CA1218774A - Image transformations on an interactive raster scan or matrix display - Google Patents
Image transformations on an interactive raster scan or matrix displayInfo
- Publication number
- CA1218774A CA1218774A CA000438411A CA438411A CA1218774A CA 1218774 A CA1218774 A CA 1218774A CA 000438411 A CA000438411 A CA 000438411A CA 438411 A CA438411 A CA 438411A CA 1218774 A CA1218774 A CA 1218774A
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- Prior art keywords
- image
- transformation
- screen
- cursor
- graphics
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
- G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
- G06F3/048—Interaction techniques based on graphical user interfaces [GUI]
- G06F3/0481—Interaction techniques based on graphical user interfaces [GUI] based on specific properties of the displayed interaction object or a metaphor-based environment, e.g. interaction with desktop elements like windows or icons, or assisted by a cursor's changing behaviour or appearance
- G06F3/04812—Interaction techniques based on cursor appearance or behaviour, e.g. being affected by the presence of displayed objects
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T11/00—2D [Two Dimensional] image generation
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- Engineering & Computer Science (AREA)
- Theoretical Computer Science (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- General Engineering & Computer Science (AREA)
- Human Computer Interaction (AREA)
- Processing Or Creating Images (AREA)
- Controls And Circuits For Display Device (AREA)
Abstract
ABSTRACT
An interactive raster-scanned display device has a microprocessor (1) and random access memory (3) which operate to issue instructions to a drawing engine (7) to cause it to load and erase image pel representation in an image buffer (9) in order to control display of images on, or removal of images from a display screen (8) in a conventional manner. A cursor control device (10) enables a user to interact by means of a cursor symbol with images on the screen. In order to reduce the demands imposed on the drawing engine during transformation of images over the screen, the system is configured so that transformation operations are performed using alternative images substituted for the full images. Each alternative image contains considerably less detail to be drawn and erased than the full image it replaces and therefore the operation is more likely to be performed at the rate desired by the user. Thus; complex graphics images containing many vectors are replaced during transformation by simple skeletal or outline drawings. If a large size cross-hair cursor is used for easy identification on a screen, then this also is replaced by a small symbol whenever it is moved. At the end of the transformation operation, the full image and the large cursor are restored on the screen.
An interactive raster-scanned display device has a microprocessor (1) and random access memory (3) which operate to issue instructions to a drawing engine (7) to cause it to load and erase image pel representation in an image buffer (9) in order to control display of images on, or removal of images from a display screen (8) in a conventional manner. A cursor control device (10) enables a user to interact by means of a cursor symbol with images on the screen. In order to reduce the demands imposed on the drawing engine during transformation of images over the screen, the system is configured so that transformation operations are performed using alternative images substituted for the full images. Each alternative image contains considerably less detail to be drawn and erased than the full image it replaces and therefore the operation is more likely to be performed at the rate desired by the user. Thus; complex graphics images containing many vectors are replaced during transformation by simple skeletal or outline drawings. If a large size cross-hair cursor is used for easy identification on a screen, then this also is replaced by a small symbol whenever it is moved. At the end of the transformation operation, the full image and the large cursor are restored on the screen.
Description
UK9-82-011 1 ~2~B7~4 I~lAGE TRANSEOR~TIONS ON AN INTERACTIVE RASTER
SCAN OR MATRIX DISPLAY
. .
5The invention relates to an interactive raster scanned or matrix display system of the type which permits two-way communication between a user of the system and a computer included as part of the system.
In such systems, the computer provides the control for the display 10so that, for example, upon receipt of signals from an input device operated by the user, a displayed:picture is modified appropriately. It is desirable for the modification to occur rapidly so that to the user it appears that the picture is changing instantaneously in response to the commands. The invention relates in particular to the use of such a 5display system for performing image transformation on the screen including such transformation made under the direct control of a user interacting with the system by means of a cursor positioning device.
There are a variety of graphical input devices such as joysticks, 20tracker balls, tabletg etc. available by means of which a user can identify a particular location or image on the screen. It is also possible to identify a position on the screen by using a keyboard propelled cursor. Here, a set of four keys may be assigned to step the cursor in each of the two directions vertically and horizontally. The 25effectiveness of these input device depends on the use of visual feedback to the user provided by a cursor displayed at the screen coordinates defined by the coordinate outputs of tne device. By controlling movement of the device, the user can steer the cursor around -the screen.
In many interactive applications provision is made for displayed images on the screen to be transformed by the user. The procedure involved includes the user moving a cursor to overl~y a point on the image in question and then issuing a signal by means of an assigned ;. .
U~9-82-011 2 ~2~8~7~
keybutton for example, to notify the computer that a transformation function is to be performed on the,image, pointed to by the cursor. The computer then operates to link the image to the cursor so that, for example, if the transformation;involves moving the image across the screen, the user can drag the image to its new position simply by moving ~he cursor with the input device. The images to be moved may include graphics line drawinys, half-tone images, text or combinations of all three. A block of text to be moved may be identified by being enclosed in a box or by pointing to the start and end of the block using a cursor.
The cursor symbol on the screen can be provided by a special purpose hardware processor. However such a processor is a relatively - expensive item in a low cost terminal and also limits the flexibility in terms of shape available to the user. It is therefore becoming increasingly common to generate the cursor by means of software thus enabling cursor shapes and sizes to be selected by the user to suit the application being performed.
A general interactive raster-scanned display system which is capable of making image transformations is described in SIGGRAPH- ACM
Computer Graphics Vol.13, No.3, August 1979. Further information on such systems may be found in Chapter 12 "Raster Display Architecture"
pages 479 to 50~ in a text book entitled 'Fundamental~ of Interactive Computer Graphics' by J D Foley and A Van Dam published by Addison-Wolsey Publications Company 1982. Basically in such systems, theindividual graphics images that constitute the picture on the screen are stored as individual graphic segments containing the graphic orders.
Then transformations may be applied individually to a given graphics segment. This in turn can result in a 'new frame' action, that is the redrawing if necessary of all visible retained information. On a raster-scanned or matrix (eg. gas panel) display, if there are many images visible and/or the images contain many vectors, it can take a UK9-82-011 3 ~8~4 relatively long time, amounting in some cases to several seconds, to redraw the entire picture.
This is particularly a ~roblem on all but high function and consequently high cost systems. The problem in as much as it relates to moving the cursor itself across the screen can be minimised by specifying that it is of small size and simple shape SQ that it can be erased and redrawn repetitively at a sufficient rate to move it across the screen at the required speed. In the case of a key operated cursor this speed is determined by the automatic typing rate of the keyboard in repetitive mode. : ~
It has been ~found howevér that when interacting with complex graphics line drawings such as integrated circuit layouts or detailed engineering drawings, a small cross-hair cursor for example can be difficult to find. Accordingly, when interacting with such complex images, it has been found to be advantageous to use a large cross-hair cursor extending from screen edge to screen edge both horizontally and vertically.
The processing power required to erase and redraw these large cursor images is not trivi,al and the time taken to perform each incremental repositioning can be long compared to the desired speed of interaction. Clearly, the problem is even worse when transforming detailed and complex images and worst of all when the transformations are performed under user control where both image and cursor are required to be moved across the screen together.
According to the invention, an interactive raster-scanned display system includes a microprocesaor controller and random access store operable to issue control signals to a drawing engine in order to display a full image on a display screen, said engine being operab'le in image transformation mode repetitively to erase and redraw such an image so as to change its position and/or shape in response to real-time UK9-82-011 4 ~ 774 commands received by said microprocessor from an interactive input device, characterised in that, in''order to reduce the demands imposed on the drawing engine during real-time image' transformation, control means are provided operable in image;~transformation mode to substitute for said full image required to be transformed, an alternative image representing said full image but containing less detail to be drawn, and on completion of said transformation to replace said alternative image by said full image.
0 In order that the invention may be fully understood, pre'ferred embodiments thereof will now b'e described by way of example with ~reference to the accompanying drawings.
In the drawings:
Figure 1 shows in simplified 'olock form a general purpose raster graphics display system to which the present invention is applied;
Figure 2 shows a number of typical images as they might appear on a screen during the performance'of transformations in accordance with the invention;
Figure 3 shows a flow diagram setting out the individual steps for invoking an alternative cursor operation performed by a display system in accordance with the invention; '~
Figure 4 shows a modification to the flow diagram in Figure 3 to - enable the display system to operate in catch-up mode should the cursor screen position fall behind the user defined position;
Figure 5 shows a flow diagram in which the detail of the alternative image is selected automatically by the display system itself to suit the available processing power; and UK9-82-011 5 ~8774 Figure 6 shows a modification of the procedure set out in the flow diagram of Figure 5 to synchronise the operation with the frame frequency of the raster visual display unit of the system.
, The basic structure of a general purpose graphics display system on which the present invention is implemented is shown in Figure 1. Such a system is well known in the art and is typical of the type of system described in the referenced chapter of the aforementioned text book by Foley and Van Dam. The basic components of a raster display system are - 10 an image creation system, an image storage system, and an image display system, all of which receive commands through an interface of a general purpose computer. Thus in the display system shown in Figure 1, a microprocessor 1 loads display lists of images to be displayed on a visual display unit (VDU) 2, into allocated space in a random access memory 3.
The display lists are in the form of graphic display segments and are provided in known manner by the 'application' being run, over input lines 4 from local peripherals for example, or perhaps over a communications line 5 -from a remote unit. The display lists of images are shown as having been allocated a block 6 of memory 3. It will be understood however that the allocation of space in such a system is under program control and the precise location of individual lists at any instant in time is of no interest. When a particular image is required to be displayed, the microprocessor points to the corresponding display list in blocX 6, and issues drawing commands to a drawing engine 7 which generates a bit map of the image to be displayed pel by pel on the screen 8. The bit map is loaded into an image refresh buffer 9 -which is sampled row by row in synchronism with the line scan of the VDU2 so that the resulting image displayed on the screen 8 is refreshed at the required frame rate. The VDU may be either a cathode ray tube display device or a matrix addressed device such employing for example a gas panel.
. --UK9-82-011 6 ~B774 l In order to interact with the image on the screen, a user is provided with cursor control deyice lO by means of which a cursor symbol can be moved from point to point over the screen. The cursor control device may take any of several forms for example a tablet, a trackball, joystick or indeed special purpose cursor keybuttons on a keyboard. In all cases, a means is provided, usually in the form of a button associated with the device, to enable a user to signal to the application program that the cursor symbol is at a position of interest on the screen. The cursor symbol may be provided by special hardware or, as is becoming increasingly common, in the form of a display list defining the cursor shape stored in allocated space in the image storage system. A full cursor display list is shown stored in block 11 in memory 3 and is displayed in the same way as other images by the drawing engine 7 generating a corresponding bit map of the cursor symbol which is loaded into the bit buffer 9 where it is held during display on the screen.
It is generally required tha~ the cursor symbol is displayed on the screen at all times and for it to be superimposed on existing images already on display on- the screen. Techniques for achieving this are well know and, since they have no relevance to the present invention, will not be described herein. The mechanism for moving a cursor across the screen, although in itself well known, has some relevance to the present invention and will be now described briefly.
The cursor position on the screen is defined by coordinate values supplied by the associated cursor control device lO. The processor 1 enters- these coordinate values into a predetermined region of memory 3 set aside for the purpose and for convenience identified as X and Y
position registers 12. A stream of new coordinate values are sent to the microprocessor as a result of a repositioning of the cursor control device by an operator. In practice, a new coordinate value is transmitted following for example each incremental ,movement of the cursor control device or alternatively at predetermined time intervals ~8~7~
1 determined by the system clock The coordinate values arriving in succession form a queue in the mic'roprocessor and are processed one at a time in the order in which they are received. The processing steps, which are quite standard, involve entering the new coordinate value from the head of the queue into the X, Y position registers 12 in memory 3, calculating the transformation using the standard linear transformation matrix for linear displacement, and sending commands to the drawing engine 7 to cause it to erase the cursor symbol at the current screen position and redraw it at the calculated pel positions specified by. the new coordinate position defined by the contents of the X, Y position register. Provided the drawing': engine is capable of erasing and redrawing the cursor symbol at a rate equal to or greater than the rate at which the new incremental position coordinates are received by the microprocessor, then it appears to the user, that the cursor symbol changes instantaneously in response to the cursor commands entered by means of the control device lO.
The cursor can be used interactively in conventional manner to identify positions on the screen at which new images are to be displayed, or to 'pick'' and transform existing images on the screen.
The techniques involved for performing there operations are well know in the art and involve repetitive erasure and redrawing not only the cursor symbol but also the image being transformed.
When interacting with complex images containing many lines, it.is desirable to use a large cursor symbol extending from screen edge to screen edge so that it is easily identified and less likely to become lost. In low cost display systems with limited processing power, the process of erasing and redrawirg such a cursor symbol can take a rela-tively long time compared with the rate at which the positioning infor-mation is received from the cursor control device. The effect is that' requests for rapid cursor repositioning may not be met and the cursor movement lags behind the input device. This can result~in overshoot and lead to general dissatisfaction of the user. When performing image ~2~8774 1 transformation for example, dragging, scaling, rotation, or even more complex transformations such as ~bber banding an image on a screen, the effect can be very much worse with each erasure and redrawing operation taking several seconds compared w'ith a typical incremental move rate of a cursor which calls for fifty such operations a second.
The present invention is aimed at reducing these problems in a low cost terminal where computing power is somewhat limited. From the human factors point of view, it is important that the cursor remains easily identifiable and does not impede the interactive nature of the process by lagging behind its intended~position. Also from the human factors point of view it would be a considerable advantage to be able to perform graphics or image transformation at the keying rate for example of a key controlled cursor.
In a system operating in accordance with the present invention, a cursor is normally drawn large and is therefore easily identifiable.
Then when the cursor is transformed, the system operates automatically to replace the full cursor with an alternative cursor image which has less detail to be draYn and therefore can be transformed at a fas-ter rate. The two cursor images full and alternative such as shown in Figure 2 as screen a and b respectively may be chosen by the program itself, or they may be selected from images suppIied by the user, o~ the application program. The alternative cursor is sh~wn stored as a display list in block 13 of memory 3.
The problem of 'losing' the cursor image is considerably reduced by judicious choice of the original full cursor image and since this full image will generally be large it can be found easily and since its position has been noted by the user before movement is requested, tracXing the alternative small cursor which automatically replaces the full cursor during the movement presents no problem. When the cursor is again stationary and no outstanding requests for cursor motion have been received by the microprocessor 1 for a predetermined period, for example 'L~ 37~4 U~9-82-011 9 1 1.5 seconds, the alternative cursor is automatically replaced by the original full cursor.
The flow diagram setting out~the sequence of steps performed by the system during a cursor movement across the screen is shown in Figure 3.
Prior to a cursor move operation, the full cursor specified by the full cursor display list lI is displayed at the current position on the screen. As soon as a cursor move request is received from the cursor control device 10, the microprocessor instructs the drawing engine 6.to 0 erase the full cursor. The microprocessor issues commands to the drawing engine so that it re-draws at the new calculated position with the incremental transformation applied, not the full cursor, but the alternative cursor defined by alternative cursor display list 13.
If user action continues to supply move requests to the micro-processor, then the alternative cursor is erased, the transfor~ation determined by the drawing engine and the alternative cursor redrawn at the transformed position. The process cycles around this loop for as long as move requests are supplied. After a predetermined time interval following the last move request, the alternative cursor is replaced once again by the full cursor. This requires the time interval from the last alternative cursor move to be monitored. This is achieved by the microprocessor entering the real time (derived from the system clock) at which the last alternative cursor move was made into predetermined storage locations of memory 3 conveniently referred to as time register 15. In the absence of user action requiring further alternative cursor movement, the real time (which of course is continually incremented at the clock rate of the system) is read and compared with the stored value of the real time in register 15. A threshold is set for the time lag, which is regarded as being sufficiently long since receipt of the last alternative cursor move, so that it can be assumed that the cursor move is complete. In the practical example chosen with the internal clock running at the frame refresh rate of the display (approximately 50 ~877~
l times/second), a lapsed uninterrupted period of 75 counts indicating a time lapse of 1.5 seconds sinçë the last alternative cursor move is considered to be adequate. As soon as this threshold is reached, the alternative cursor is erased and replaced by the full cursor which remains displayed until a new cursor move operation is requested.
The system so far described can be modified to operate in catch-up mode should the motion of the cursor on the screen fall behind the motion requesting input. This is most likely to occur during the erasing of the full image at the start of a transformation operation which takes a relatively long time. A part flow diagram shown in Figure 4 details the modification to the system and is intended to replace the portion of the flow diagram in Figure 3 lying between the point A and B. A system operating in catch-up mode reads all the input requests for cursor motion and transforms the cursor image in one step to the position it would have been in, had the program been able to keep up .
So far the operation has been concerned with simple translational movement of a cursor across the screen. The same procedure may also be adopted for performing translations or other transformations of the displayed images provided by the application. Thus for example whenever a transformation is required of an image, which would by virtue of its complexity impose a time penalty on the operation, a simplified image is substituted during the period of transformation. When the transformation has been comp~eted, the original complex image is returned.
In order to perform this operation as set out in the flow diag~am of Figure 3, or as modified by the part flow diagram in Figure 4, additional display lists representing simple substitute images for the complex images must be provided by the application. Those complex images provided with alternative images are marked by the application in a way detectable by the microprocessor. Thereafter, whenever trans-formations of images identified by the mark are called for, the ~IL2:18'77~
microprocessor adopts the procedure as described in the flow diagram of Figure 3 and 'points' to the full'image or alternative partial image as appropriate. An example of a complex image is shown as screen c in Figure 2 and an alternative s,imple skeletal image for substitution during transformations is shown as screen d. Clearly the nature of the alternative image will be selected to suit each individual case and may take any of several forms. Other typical alternative images are shown in Figure 2 where screen e represent a convex hull boundary of a three dimensional object's image, and screen f represents a simple rectang,ular frame that would enclose a full image.
For the sake of simplicity the example described dealt with a simple translation of a 2-dimensional image, however quite clearly, the invention is equally applicable for performing other 2 dimensional transformations such as scale change and rotation. In these cases additional registers up to six in number would need to be defined in the random access memory to hold the linear transformation elements used during the calculations. The transformation matrices are described in detail in the aforementioned text book by Foley and Van Dam at page 254.
Equally the invention is applicable to transforming 3-dimensional images, although in this case up to twelve registers would be required to hold the transformation elements.
The disadvantage of the method of implementing the invention described so far is that the alternative images need to be provided beforehand by the application. The images are therefore invariant and accordingly are unlikely to be the most appropriate for each and every transformation. For example, with all but the key controlled cursor devices, the speed at which a cursor and its attached image are moved around the screen is determined by the user. If the movement is fast, even the alternative image may be too large for the drawing engine to process at the desired rate. Conversely, if the required rate of movement is slow, then even if the drawing engine~ is capable of processing the full image, the ... .
l procedure will still automatically substitute the alternative image even though it may under the circumstan'ces be unnecessary.
The second embodiment of the invention utilises an interrupt system which overcomes this problem by enabling the system to specify its own alternative image by using only those vectors of the full image that can be drawn and erased in the available time interval between move commands. In this case, the display list of vectors presented for an image is ordered by the user so that the most important features of, the image are specified, and hence drawn, first. Thus for exampie the ordering of the vectors forming the image on screen c of Figure 2 may be such that those vectors forming the skeletal image on screen d are drawn first should the rate of transformation be such that an alternative image is required.
The flow diagram setting out the sequences of steps for performing image transformation operations with the system configured according to the second embodiment of the invention is shown in Figure 5.
Following receipt- of a user action interrupt from the cursor control device lO, resulting in the appearance of a move request in the input queue, the microprocessor 1 issues a STOP command to the drawing engine 7. Since it is important to save as much time as possible, any remaining drawing commands on the drawing queue currently being processed by the drawing engine are purged from the system. An instruction is issued to the drawing engine to erase the existing image from the screen. The transformation specified by the new coordinate values in reqister 13 is applied to the display list and a new DRAW
command is issued to the drawing engine 7. The engine then draws as many vectors as it can in the new incrementally transformed position until another move request appears in the input queue from device 10.
This is regarded by the system as another user interrupt and the-whole process is repeated.
UK9-82-011 13 ~Z~77~
l It is desirable from the human factors point of view for drawing of an image on the screen to be sync~ronised with the frame scan mechanism.
To achieve this, the display system is modified as shown by the part flow diagram shown in Pigure 6~which replaces the portion of the flow diagram of Figure S lying between point A and B. In this variation, a system real time interrupt occurs at the start of every frame scan (i.e.
50 times/sec). At each interrupt, the input queue is interrogated to see whether there is any outstanding user action waiting to be processed. If a move reques-t is found then the remaining procedure 0 detailed in the flow chart of Figure 5-and described above is fol~owed.
:
This mechanism tied to the frame synch of the terminal would resul-t in difference alternative images being drawn on different speed terminals. However, it would not require the code for frame selection to be modified when it is transported to a new, different speed terminal, thus providing a degree of device independence.
Finally, a further advantage of displaying alternative images is that since these can be made small, a correspondingly small amount of image buffer space is- required for its display. Further, since this space is small, its use can be reasonably special cased, so as to recover the space when the image is erased. This may be done by saving the relevant contents of the bit buffer before the image is drawn and then restoring them when the image is later erased.
SCAN OR MATRIX DISPLAY
. .
5The invention relates to an interactive raster scanned or matrix display system of the type which permits two-way communication between a user of the system and a computer included as part of the system.
In such systems, the computer provides the control for the display 10so that, for example, upon receipt of signals from an input device operated by the user, a displayed:picture is modified appropriately. It is desirable for the modification to occur rapidly so that to the user it appears that the picture is changing instantaneously in response to the commands. The invention relates in particular to the use of such a 5display system for performing image transformation on the screen including such transformation made under the direct control of a user interacting with the system by means of a cursor positioning device.
There are a variety of graphical input devices such as joysticks, 20tracker balls, tabletg etc. available by means of which a user can identify a particular location or image on the screen. It is also possible to identify a position on the screen by using a keyboard propelled cursor. Here, a set of four keys may be assigned to step the cursor in each of the two directions vertically and horizontally. The 25effectiveness of these input device depends on the use of visual feedback to the user provided by a cursor displayed at the screen coordinates defined by the coordinate outputs of tne device. By controlling movement of the device, the user can steer the cursor around -the screen.
In many interactive applications provision is made for displayed images on the screen to be transformed by the user. The procedure involved includes the user moving a cursor to overl~y a point on the image in question and then issuing a signal by means of an assigned ;. .
U~9-82-011 2 ~2~8~7~
keybutton for example, to notify the computer that a transformation function is to be performed on the,image, pointed to by the cursor. The computer then operates to link the image to the cursor so that, for example, if the transformation;involves moving the image across the screen, the user can drag the image to its new position simply by moving ~he cursor with the input device. The images to be moved may include graphics line drawinys, half-tone images, text or combinations of all three. A block of text to be moved may be identified by being enclosed in a box or by pointing to the start and end of the block using a cursor.
The cursor symbol on the screen can be provided by a special purpose hardware processor. However such a processor is a relatively - expensive item in a low cost terminal and also limits the flexibility in terms of shape available to the user. It is therefore becoming increasingly common to generate the cursor by means of software thus enabling cursor shapes and sizes to be selected by the user to suit the application being performed.
A general interactive raster-scanned display system which is capable of making image transformations is described in SIGGRAPH- ACM
Computer Graphics Vol.13, No.3, August 1979. Further information on such systems may be found in Chapter 12 "Raster Display Architecture"
pages 479 to 50~ in a text book entitled 'Fundamental~ of Interactive Computer Graphics' by J D Foley and A Van Dam published by Addison-Wolsey Publications Company 1982. Basically in such systems, theindividual graphics images that constitute the picture on the screen are stored as individual graphic segments containing the graphic orders.
Then transformations may be applied individually to a given graphics segment. This in turn can result in a 'new frame' action, that is the redrawing if necessary of all visible retained information. On a raster-scanned or matrix (eg. gas panel) display, if there are many images visible and/or the images contain many vectors, it can take a UK9-82-011 3 ~8~4 relatively long time, amounting in some cases to several seconds, to redraw the entire picture.
This is particularly a ~roblem on all but high function and consequently high cost systems. The problem in as much as it relates to moving the cursor itself across the screen can be minimised by specifying that it is of small size and simple shape SQ that it can be erased and redrawn repetitively at a sufficient rate to move it across the screen at the required speed. In the case of a key operated cursor this speed is determined by the automatic typing rate of the keyboard in repetitive mode. : ~
It has been ~found howevér that when interacting with complex graphics line drawings such as integrated circuit layouts or detailed engineering drawings, a small cross-hair cursor for example can be difficult to find. Accordingly, when interacting with such complex images, it has been found to be advantageous to use a large cross-hair cursor extending from screen edge to screen edge both horizontally and vertically.
The processing power required to erase and redraw these large cursor images is not trivi,al and the time taken to perform each incremental repositioning can be long compared to the desired speed of interaction. Clearly, the problem is even worse when transforming detailed and complex images and worst of all when the transformations are performed under user control where both image and cursor are required to be moved across the screen together.
According to the invention, an interactive raster-scanned display system includes a microprocesaor controller and random access store operable to issue control signals to a drawing engine in order to display a full image on a display screen, said engine being operab'le in image transformation mode repetitively to erase and redraw such an image so as to change its position and/or shape in response to real-time UK9-82-011 4 ~ 774 commands received by said microprocessor from an interactive input device, characterised in that, in''order to reduce the demands imposed on the drawing engine during real-time image' transformation, control means are provided operable in image;~transformation mode to substitute for said full image required to be transformed, an alternative image representing said full image but containing less detail to be drawn, and on completion of said transformation to replace said alternative image by said full image.
0 In order that the invention may be fully understood, pre'ferred embodiments thereof will now b'e described by way of example with ~reference to the accompanying drawings.
In the drawings:
Figure 1 shows in simplified 'olock form a general purpose raster graphics display system to which the present invention is applied;
Figure 2 shows a number of typical images as they might appear on a screen during the performance'of transformations in accordance with the invention;
Figure 3 shows a flow diagram setting out the individual steps for invoking an alternative cursor operation performed by a display system in accordance with the invention; '~
Figure 4 shows a modification to the flow diagram in Figure 3 to - enable the display system to operate in catch-up mode should the cursor screen position fall behind the user defined position;
Figure 5 shows a flow diagram in which the detail of the alternative image is selected automatically by the display system itself to suit the available processing power; and UK9-82-011 5 ~8774 Figure 6 shows a modification of the procedure set out in the flow diagram of Figure 5 to synchronise the operation with the frame frequency of the raster visual display unit of the system.
, The basic structure of a general purpose graphics display system on which the present invention is implemented is shown in Figure 1. Such a system is well known in the art and is typical of the type of system described in the referenced chapter of the aforementioned text book by Foley and Van Dam. The basic components of a raster display system are - 10 an image creation system, an image storage system, and an image display system, all of which receive commands through an interface of a general purpose computer. Thus in the display system shown in Figure 1, a microprocessor 1 loads display lists of images to be displayed on a visual display unit (VDU) 2, into allocated space in a random access memory 3.
The display lists are in the form of graphic display segments and are provided in known manner by the 'application' being run, over input lines 4 from local peripherals for example, or perhaps over a communications line 5 -from a remote unit. The display lists of images are shown as having been allocated a block 6 of memory 3. It will be understood however that the allocation of space in such a system is under program control and the precise location of individual lists at any instant in time is of no interest. When a particular image is required to be displayed, the microprocessor points to the corresponding display list in blocX 6, and issues drawing commands to a drawing engine 7 which generates a bit map of the image to be displayed pel by pel on the screen 8. The bit map is loaded into an image refresh buffer 9 -which is sampled row by row in synchronism with the line scan of the VDU2 so that the resulting image displayed on the screen 8 is refreshed at the required frame rate. The VDU may be either a cathode ray tube display device or a matrix addressed device such employing for example a gas panel.
. --UK9-82-011 6 ~B774 l In order to interact with the image on the screen, a user is provided with cursor control deyice lO by means of which a cursor symbol can be moved from point to point over the screen. The cursor control device may take any of several forms for example a tablet, a trackball, joystick or indeed special purpose cursor keybuttons on a keyboard. In all cases, a means is provided, usually in the form of a button associated with the device, to enable a user to signal to the application program that the cursor symbol is at a position of interest on the screen. The cursor symbol may be provided by special hardware or, as is becoming increasingly common, in the form of a display list defining the cursor shape stored in allocated space in the image storage system. A full cursor display list is shown stored in block 11 in memory 3 and is displayed in the same way as other images by the drawing engine 7 generating a corresponding bit map of the cursor symbol which is loaded into the bit buffer 9 where it is held during display on the screen.
It is generally required tha~ the cursor symbol is displayed on the screen at all times and for it to be superimposed on existing images already on display on- the screen. Techniques for achieving this are well know and, since they have no relevance to the present invention, will not be described herein. The mechanism for moving a cursor across the screen, although in itself well known, has some relevance to the present invention and will be now described briefly.
The cursor position on the screen is defined by coordinate values supplied by the associated cursor control device lO. The processor 1 enters- these coordinate values into a predetermined region of memory 3 set aside for the purpose and for convenience identified as X and Y
position registers 12. A stream of new coordinate values are sent to the microprocessor as a result of a repositioning of the cursor control device by an operator. In practice, a new coordinate value is transmitted following for example each incremental ,movement of the cursor control device or alternatively at predetermined time intervals ~8~7~
1 determined by the system clock The coordinate values arriving in succession form a queue in the mic'roprocessor and are processed one at a time in the order in which they are received. The processing steps, which are quite standard, involve entering the new coordinate value from the head of the queue into the X, Y position registers 12 in memory 3, calculating the transformation using the standard linear transformation matrix for linear displacement, and sending commands to the drawing engine 7 to cause it to erase the cursor symbol at the current screen position and redraw it at the calculated pel positions specified by. the new coordinate position defined by the contents of the X, Y position register. Provided the drawing': engine is capable of erasing and redrawing the cursor symbol at a rate equal to or greater than the rate at which the new incremental position coordinates are received by the microprocessor, then it appears to the user, that the cursor symbol changes instantaneously in response to the cursor commands entered by means of the control device lO.
The cursor can be used interactively in conventional manner to identify positions on the screen at which new images are to be displayed, or to 'pick'' and transform existing images on the screen.
The techniques involved for performing there operations are well know in the art and involve repetitive erasure and redrawing not only the cursor symbol but also the image being transformed.
When interacting with complex images containing many lines, it.is desirable to use a large cursor symbol extending from screen edge to screen edge so that it is easily identified and less likely to become lost. In low cost display systems with limited processing power, the process of erasing and redrawirg such a cursor symbol can take a rela-tively long time compared with the rate at which the positioning infor-mation is received from the cursor control device. The effect is that' requests for rapid cursor repositioning may not be met and the cursor movement lags behind the input device. This can result~in overshoot and lead to general dissatisfaction of the user. When performing image ~2~8774 1 transformation for example, dragging, scaling, rotation, or even more complex transformations such as ~bber banding an image on a screen, the effect can be very much worse with each erasure and redrawing operation taking several seconds compared w'ith a typical incremental move rate of a cursor which calls for fifty such operations a second.
The present invention is aimed at reducing these problems in a low cost terminal where computing power is somewhat limited. From the human factors point of view, it is important that the cursor remains easily identifiable and does not impede the interactive nature of the process by lagging behind its intended~position. Also from the human factors point of view it would be a considerable advantage to be able to perform graphics or image transformation at the keying rate for example of a key controlled cursor.
In a system operating in accordance with the present invention, a cursor is normally drawn large and is therefore easily identifiable.
Then when the cursor is transformed, the system operates automatically to replace the full cursor with an alternative cursor image which has less detail to be draYn and therefore can be transformed at a fas-ter rate. The two cursor images full and alternative such as shown in Figure 2 as screen a and b respectively may be chosen by the program itself, or they may be selected from images suppIied by the user, o~ the application program. The alternative cursor is sh~wn stored as a display list in block 13 of memory 3.
The problem of 'losing' the cursor image is considerably reduced by judicious choice of the original full cursor image and since this full image will generally be large it can be found easily and since its position has been noted by the user before movement is requested, tracXing the alternative small cursor which automatically replaces the full cursor during the movement presents no problem. When the cursor is again stationary and no outstanding requests for cursor motion have been received by the microprocessor 1 for a predetermined period, for example 'L~ 37~4 U~9-82-011 9 1 1.5 seconds, the alternative cursor is automatically replaced by the original full cursor.
The flow diagram setting out~the sequence of steps performed by the system during a cursor movement across the screen is shown in Figure 3.
Prior to a cursor move operation, the full cursor specified by the full cursor display list lI is displayed at the current position on the screen. As soon as a cursor move request is received from the cursor control device 10, the microprocessor instructs the drawing engine 6.to 0 erase the full cursor. The microprocessor issues commands to the drawing engine so that it re-draws at the new calculated position with the incremental transformation applied, not the full cursor, but the alternative cursor defined by alternative cursor display list 13.
If user action continues to supply move requests to the micro-processor, then the alternative cursor is erased, the transfor~ation determined by the drawing engine and the alternative cursor redrawn at the transformed position. The process cycles around this loop for as long as move requests are supplied. After a predetermined time interval following the last move request, the alternative cursor is replaced once again by the full cursor. This requires the time interval from the last alternative cursor move to be monitored. This is achieved by the microprocessor entering the real time (derived from the system clock) at which the last alternative cursor move was made into predetermined storage locations of memory 3 conveniently referred to as time register 15. In the absence of user action requiring further alternative cursor movement, the real time (which of course is continually incremented at the clock rate of the system) is read and compared with the stored value of the real time in register 15. A threshold is set for the time lag, which is regarded as being sufficiently long since receipt of the last alternative cursor move, so that it can be assumed that the cursor move is complete. In the practical example chosen with the internal clock running at the frame refresh rate of the display (approximately 50 ~877~
l times/second), a lapsed uninterrupted period of 75 counts indicating a time lapse of 1.5 seconds sinçë the last alternative cursor move is considered to be adequate. As soon as this threshold is reached, the alternative cursor is erased and replaced by the full cursor which remains displayed until a new cursor move operation is requested.
The system so far described can be modified to operate in catch-up mode should the motion of the cursor on the screen fall behind the motion requesting input. This is most likely to occur during the erasing of the full image at the start of a transformation operation which takes a relatively long time. A part flow diagram shown in Figure 4 details the modification to the system and is intended to replace the portion of the flow diagram in Figure 3 lying between the point A and B. A system operating in catch-up mode reads all the input requests for cursor motion and transforms the cursor image in one step to the position it would have been in, had the program been able to keep up .
So far the operation has been concerned with simple translational movement of a cursor across the screen. The same procedure may also be adopted for performing translations or other transformations of the displayed images provided by the application. Thus for example whenever a transformation is required of an image, which would by virtue of its complexity impose a time penalty on the operation, a simplified image is substituted during the period of transformation. When the transformation has been comp~eted, the original complex image is returned.
In order to perform this operation as set out in the flow diag~am of Figure 3, or as modified by the part flow diagram in Figure 4, additional display lists representing simple substitute images for the complex images must be provided by the application. Those complex images provided with alternative images are marked by the application in a way detectable by the microprocessor. Thereafter, whenever trans-formations of images identified by the mark are called for, the ~IL2:18'77~
microprocessor adopts the procedure as described in the flow diagram of Figure 3 and 'points' to the full'image or alternative partial image as appropriate. An example of a complex image is shown as screen c in Figure 2 and an alternative s,imple skeletal image for substitution during transformations is shown as screen d. Clearly the nature of the alternative image will be selected to suit each individual case and may take any of several forms. Other typical alternative images are shown in Figure 2 where screen e represent a convex hull boundary of a three dimensional object's image, and screen f represents a simple rectang,ular frame that would enclose a full image.
For the sake of simplicity the example described dealt with a simple translation of a 2-dimensional image, however quite clearly, the invention is equally applicable for performing other 2 dimensional transformations such as scale change and rotation. In these cases additional registers up to six in number would need to be defined in the random access memory to hold the linear transformation elements used during the calculations. The transformation matrices are described in detail in the aforementioned text book by Foley and Van Dam at page 254.
Equally the invention is applicable to transforming 3-dimensional images, although in this case up to twelve registers would be required to hold the transformation elements.
The disadvantage of the method of implementing the invention described so far is that the alternative images need to be provided beforehand by the application. The images are therefore invariant and accordingly are unlikely to be the most appropriate for each and every transformation. For example, with all but the key controlled cursor devices, the speed at which a cursor and its attached image are moved around the screen is determined by the user. If the movement is fast, even the alternative image may be too large for the drawing engine to process at the desired rate. Conversely, if the required rate of movement is slow, then even if the drawing engine~ is capable of processing the full image, the ... .
l procedure will still automatically substitute the alternative image even though it may under the circumstan'ces be unnecessary.
The second embodiment of the invention utilises an interrupt system which overcomes this problem by enabling the system to specify its own alternative image by using only those vectors of the full image that can be drawn and erased in the available time interval between move commands. In this case, the display list of vectors presented for an image is ordered by the user so that the most important features of, the image are specified, and hence drawn, first. Thus for exampie the ordering of the vectors forming the image on screen c of Figure 2 may be such that those vectors forming the skeletal image on screen d are drawn first should the rate of transformation be such that an alternative image is required.
The flow diagram setting out the sequences of steps for performing image transformation operations with the system configured according to the second embodiment of the invention is shown in Figure 5.
Following receipt- of a user action interrupt from the cursor control device lO, resulting in the appearance of a move request in the input queue, the microprocessor 1 issues a STOP command to the drawing engine 7. Since it is important to save as much time as possible, any remaining drawing commands on the drawing queue currently being processed by the drawing engine are purged from the system. An instruction is issued to the drawing engine to erase the existing image from the screen. The transformation specified by the new coordinate values in reqister 13 is applied to the display list and a new DRAW
command is issued to the drawing engine 7. The engine then draws as many vectors as it can in the new incrementally transformed position until another move request appears in the input queue from device 10.
This is regarded by the system as another user interrupt and the-whole process is repeated.
UK9-82-011 13 ~Z~77~
l It is desirable from the human factors point of view for drawing of an image on the screen to be sync~ronised with the frame scan mechanism.
To achieve this, the display system is modified as shown by the part flow diagram shown in Pigure 6~which replaces the portion of the flow diagram of Figure S lying between point A and B. In this variation, a system real time interrupt occurs at the start of every frame scan (i.e.
50 times/sec). At each interrupt, the input queue is interrogated to see whether there is any outstanding user action waiting to be processed. If a move reques-t is found then the remaining procedure 0 detailed in the flow chart of Figure 5-and described above is fol~owed.
:
This mechanism tied to the frame synch of the terminal would resul-t in difference alternative images being drawn on different speed terminals. However, it would not require the code for frame selection to be modified when it is transported to a new, different speed terminal, thus providing a degree of device independence.
Finally, a further advantage of displaying alternative images is that since these can be made small, a correspondingly small amount of image buffer space is- required for its display. Further, since this space is small, its use can be reasonably special cased, so as to recover the space when the image is erased. This may be done by saving the relevant contents of the bit buffer before the image is drawn and then restoring them when the image is later erased.
Claims (30)
1. An interactive raster scanned display system including a microprocessor and random-access store operable to issue control signals to a drawing engine in order to display a full image on a display screen, said engine being arranged in operation in image transformation mode repetitively to erase and redraw such an image so as to change its position and/or shape in response to real-time commands received by said microprocessor from an interactive input device, characterized in that, in order to reduce the demands imposed on the drawing engine during real-time image transformation, control means are provided in said system arranged in operation in image transformation mode to, by and during said change in position and/or shape of said image, substitute for said full image required to be transformed, an alternative image representing said full image but containing less detail to be drawn, and on completion of said transformation to replace said alternative image by said full image.
2. An interactive raster-scanned display system as claimed in claim 1, in which said control means operates upon receipt of a first command from said input device involving image transformation to cause said engine to erase the full image to be transformed currently on display and to draw, incrementally transformed as required by said first command, said alternative image, said control means being further operable in response to receipt of subsequent commands to cause said engine repetitively to erase and redraw the alternative image with incremental transformation as required in turn by each of said subsequent commands.
3. An interactive raster-scanned display system as claimed in claim 2, in which said transformation commands from said input device form an input queue and are processed in order of arrival by said microprocessor, said control means being operable on receipt of a subsequent transformation command before the current drawing operation of the alternative image is complete to cause said engine to erase the partially drawn alternative image and to redraw said alternative image transformed as required by the most recently received command in said queue.
4. An interactive raster-scanned display system as claimed in claim 1, claim 2 or claim 3, including means for monitoring the elapsed time from receipt by said microprocessor of the most recent command from said input device, the arrangement being such that the current transfor-mation is regarded as having been completed when said elapsed time exceeds a predetermined value.
5. An interactive raster-scanned display system as claimed in claim 1, claim 2 or claim 3, including means for monitoring the elapsed time from receipt by said microprocessor of the most recent command from said input device, the arrangement being such that the current transfor-mation is regarded as having been completed when said elapsed time exceeds a predetermined value, and said full and alternative images are stored in the form of vector display lists in available allocated space in said random access.
6. An interactive raster-scanned display system as claimed in claim 1, claim 2 or claim 3, including means for monitoring the elapsed time from receipt by said microprocessor of the most recent command from said input device, the arrangement being such that the current transfor-mation is regarded as having been completed when said elapsed time exceeds a predetermined value, said full and alternative images are stored in the form of vector display lists in available allocated space in said random access, and said control means includes a pointer mechanism arranged in operation to identify the location of a display list of a full image to be displayed and to identify the location of a display list of the associated alternative image upon invocation of transformation of said full image.
7. An interactive raster-scanned display system as claimed in claim 1, claim 2 or claim 3, including means for monitoring the elapsed time from receipt by said microprocessor of the most recent command from said input device, the arrangement being such that the current transfor-mation is regarded as having been completed when said elapsed time exceeds a predetermined value, said full and alternative images are stored in the form of vector display lists in available allocated space in said random access, and said full image is stored in said random access store as a vector display list ordered so as to be selected by said engine during a drawing operation in a predetermined sequence of vectors, said control means being arranged to be operable in response to receipt by said microprocessor of each transformation command from the input device to cause said engine to erase the image currently on display and to commence to re-draw said image from said ordered list incrementally transformed as required by said transformation command, the drawing operation continuing until receipt of a subsequent transfor-mation command where upon the process is repeated.
8. An interactive raster-scanned display system as claimed in claim 2 or 3, in which start of an alternative image draw operation by said engine is synchronized with the start of a new frame scan of said display screen.
9. An interactive raster-scanned display system as claimed in claim 2 or claim 3, including means for monitoring the elapsed time from receipt by said microprocessor of the most recent command from said input device, the arrangement being such that the current transformation is regarded as having been completed when said elapsed time exceeds a predetermined value, and in which start of an alternative image draw operation by said engine is synchronized with the start of a new frame scan of said display screen.
10. An interactive raster-scanned display system as claimed in claim 2 or claim 3, including means for monitoring the elapsed time from receipt by said microprocessor of the most recent command from said input device, the arrangement being such that the current transformation is regarded as having been completed when said elapsed time exceeds a predetermined value, said full and alternative images are stored in the form of vector display lists in available allocated space in said random access, and start of an alternative image draw operation by said engine is synchronized with the start of a new frame scan of said display screen.
11. An interactive raster-scanned display system as claimed in claim 2 or claim 3, including means for monitoring the elapsed time from receipt by said microprocessor of the most recent command from said input device, the arrangement being such that the current transformation is regarded as having been completed when said elapsed time exceeds a predetermined value, said full and alternative images are stored in the form of vector display lists in available allocated space in said random access, said control means includes a pointer mechanism arranged in operation to identify the location of a display list of a full image to be displayed and to identify the location of a display list of the associated alternative image upon invocation of transformation of said full image, and start of an alternative image draw operation by said engine is synchronized with the start of a new frame scan of said display screen.
12. An interactive raster-scanned display system as claimed in claim 2 or claim 3, including means for monitoring the elapsed time from receipt by said microprocessor of the most recent command from said input device, the arrangement being such that the current transformation is regarded as having been completed when said elapsed time exceeds a predetermined value, said full and alternative images are stored in the form of vector display lists in available allocated space in said random access, said full image is stored in said random access store as a vector display list ordered so as to be selected by said engine during a drawing operation in a predetermined sequence of vectors, said control means being arranged to be operable in response to receipt by said microprocessor of each transformation command from the input device to cause said engine to erase the image currently on display and to commence to re-draw said image from said ordered list incrementally transformed as required by said transformation command the drawing operation continuing until receipt of a subsequent transformation command where upon the process is repeated, and start of an alternative image draw operation by said engine is synchronized with the start of a new frame scan of said display screen.
13. An interactive raster-scanned display system as claimed in claim 1, claim 2 or claim 3, including means for monitoring the elapsed time from receipt by said microprocessor of the most recent command from said input device, the arrangement being such that the current transfor-mation is regarded as having been completed when said elapsed time exceeds a predetermined value, said system being organized so as to permit a user to identify by means of a cursor symbol a graphics or like image on the screen for transformation, and to control said transformation interactively by means of the controlled movement of said cursor, across the screen whilst attached to said image, the arrangement being such that during transformation at least said graphics or like-image is replaced by an alternative image representing the graphics or like image on the screen but containing less detail to be drawn.
14. An interactive raster-scanned display system as claimed in claim 1, claim 2 or claim 3, including means for monitoring the elapsed time from receipt by said microprocessor of the most recent command from said input device, the arrangement being such that the current transfor-mation is regarded as having been completed when said elapsed time exceeds a predetermined value, and said full and alternative images are stored in the form of vector display lists in available allocated space in said random access, said system being organized so as to permit a user to identify by means of a cursor symbol a graphics or like image on the screen for transformation, and to control said transformation interactively by means of the controlled movement of said cursor, across the screen whilst attached to said image, the arrangement being such that during transformation at least said graphics or like-image is replaced by an alternative image representing the graphics or like image on the screen but containing less detail to be drawn.
15. An interactive raster-scanned display system as claimed in claim 1, claim 2 or claim 3, including means for monitoring the elapsed time from receipt by said microprocessor of the most recent command from said input device, the arrangement being such that the current transfor-mation is regarded as having been completed when said elapsed time exceeds a predetermined value, said system being organized so as to permit a user to identify by means of a cursor symbol a graphics or like image on the screen for transformation, and to control said transformation interactively by means of the controlled movement of said cursor, across the screen whilst attached to said image, the arrangement being such that during transformation at least said graphics or like-image is replaced by an alternative image representing the graphics or like image on the screen but containing less detail to be drawn, wherein said cursor symbol is a full cross-hair symbol extending from screen edge to screen edge in both vertical and horizontal directions and during translation of said cursor symbol across the screen, whether attached to a graphics or like symbol or not, in response to commands from a cursor control input device operated by a user, is replaced by a relatively small cross-hair symbol containing considerably less detail.
16. An interactive raster-scanned display system as claimed in claim 2 or claim 3, in which start of an alternative image draw operation by said engine is synchronized with the start of a new frame scan of said display screen, and said system being organized so as to permit a user to identify by means of a cursor symbol a graphics or like image on the screen for transformation, and to control said transformation interactively by means of the controlled movement of said cursor, across the screen whilst attached to said image, the arrangement being such that during transformation at least said graphics or like-image is replaced by an alternative image representing the graphics or like image on the screen but containing less detail to be drawn.
17. An interactive raster-scanned display system as claimed in claim 1, claim 2 or claim 3) including means for monitoring the elapsed time from receipt by said microprocessor of the most recent command from said input device, the arrangement being such that the current transfor-mation is regarded as having been completed when said elapsed time exceeds a predetermined value, said full and alternative images are stored in the form of vector display lists in available allocated space in said random access, said system being organized so as to permit a user to identify by means of a cursor symbol a graphics or like image on the screen for transformation, and to control said transformation interactively by means of the controlled movement of said cursor, across the screen whilst attached to said image, the arrangement being such that during transformation at least said graphics or like-image is replaced by an alternative image representing the graphics or like image on the screen but containing less detail to be drawn, and wherein said cursor symbol is a full cross-hair symbol extending from screen edge to screen edge in both vertical and horizontal directions and during translation of said cursor symbol across the screen, whether attached to a graphics or like symbol or not, in response to commands from a cursor control input device operated by a user, is replaced by a relatively small cross-hair symbol containing considerably less detail.
18. An interactive raster-scanned display system as claimed in claim 1, claim 2 or claim 3, including means for monitoring the elapsed time from receipt by said microprocessor of the most recent command from said input device, the arrangement being such that the current transfor-mation is regarded as having been completed when said elapsed time exceeds a predetermined value, said full and alternative images are stored in the form of vector display lists in available allocated space in said random access, said system being organized so as to permit a user to identify by means of a cursor symbol a graphics or like image on the screen for transformation, and to control said transformation interactively by means of the controlled movement of said cursor, across the screen whilst attached to said image, the arrangement being such that during transformation at least said graphics or like-image is replaced by an alternative image representing the graphics or like image on the screen but containing less detail to be drawn.
19. An interactive raster-scanned display system as claimed in claim 1, claim 2 or claim 3, including means for monitoring the elapsed time from receipt by said microprocessor of the most recent command from said input device, the arrangement being such that the current transfor-mation is regarded as having been completed when said elapsed time exceeds a predetermined value, said full and alternative images are stored in the form of vector display lists in available allocated space in said random access, said control means includes a pointer mechanism arranged in operation to identify the location of a display list of a full image to be displayed and to identify the location of a display list of the associated alternative image upon invocation of transformation of said full image, said system being organized so as to permit a user to identify by means of a cursor symbol a graphics or like image on the screen for transformation, and to control said transformation interactively by means of the controlled movement of said cursor, across the screen whilst attached to said image, the arrangement being such that during transformation at least said graphics or like-image is replaced by an alternative image representing the graphics or like image on the screen but containing less detail to be drawn, and wherein said cursor symbol is a full cross-hair symbol extending from screen edge to screen edge in both vertical and horizontal directions and during translation of said cursor symbol across the screen, whether attached to a graphics or like symbol or not, in response to commands from a cursor control input device operated by a user, is replaced by a relatively small cross-hair symbol containing considerably less detail.
20. An interactive raster-scanned display system as claimed in claim l, claim 2 or claim 3, including means for monitoring the elapsed time from receipt by said microprocessor of the most recent command from said input device, the arrangement being such that the current transfor-mation is regarded as having been completed when said elapsed time exceeds a predetermined value, said full and alternative images are stored in the form of vector display lists in available allocated space in said random access, said full image is stored in said random access store as a vector display list ordered so as to be selected by said engine during a drawing operation in a predetermined sequence of vectors, said control means being arranged to be operable in response to receipt by said microprocessor of each transformation command from the input device to cause said engine to erase the image currently on display and to commence to re-draw said image from said ordered list incrementally transformed as required by said transformation command, the drawing operation continuing until receipt of a subsequent transformation command where upon the process is repeated, said system being organized so as to permit a user to identify by means of a cursor symbol a graphics or like image on the screen for transformation, and to control said transformation interactively by means of the controlled movement of said cursor, across the screen whilst attach d to said image, the arrangement being such that during transformation at least said graphics or like-image is replaced by an alternative image representing the graphics or like image on the screen but containing less detail to be drawn.
21. An interactive raster-scanned display system as claimed in claim 1, claim 2 or claim 3, including means for monitoring the elapsed time from receipt by said microprocessor of the most recent command from said input device, the arrangement being such that the current transfor-mation is regarded as having been completed when said elapsed time exceeds a predetermined value, said full and alternative images are stored in the form of vector display lists in available allocated space in said random access, said full image is stored in said random access store as a vector display list ordered so as to be selected by said engine during a drawing operation in a predetermined sequence of vectors, said control means being arranged to be operable in response to receipt by said microprocessor of each transformation command from the input device to cause said engine to erase the image currently on display and to commence to re-draw said image from said ordered list incrementally transformed as required by said transformation command, the drawing operation continuing until receipt of a subsequent transformation command where upon the process is repeated, said system being organized so as to permit a user to identify by means of a cursor symbol a graphics or like image on the screen for transformation, and to control said transformation interactively by means of the controlled movement of said cursor, across the screen whilst attached to said image, the arrangement being such that during transformation at least said graphics or like-image is replaced by an alternative image representing the graphics or like image on the screen but containing less detail to be drawn, and wherein said cursor symbol is a full cross-hair symbol extending from screen edge to screen edge in both vertical and horizontal directions and during translation of said cursor symbol across the screen, whether attached to a graphics or like symbol or not, in response to commands from a cursor control input device operated by a user, is replaced by a relatively small cross-hair symbol containing considerably less detail.
22. An interactive raster-scanned display system as claimed in claim 2 or 3, in which start of an alternative image draw operation by said engine is synchronized with the start of a new frame scan of said display screen, said system being organized so as to permit a user to identify by means of a cursor symbol a graphics or like image on the screen for transformation, and to control said transformation interactively by means of the controlled movement of said cursor, across the screen whilst attached to said image, the arrangement being such that during transformation at least said graphics or like-image is replaced by an alternative image representing the graphics or like image on the screen but containing less detail to be drawn, and wherein said cursor symbol is a full cross-hair symbol extending from screen edge to screen edge in both vertical and horizontal directions and during translation of said cursor symbol across the screen, whether attached to a graphics or like symbol or not, in response to commands from a cursor control input device operated by a user, is replaced by a relatively small cross-hair symbol containing considerably less detail.
23. An interactive raster-scanned display system as claimed in claim 2 or claim 3, including means for monitoring the elapsed time from receipt by said microprocessor of the most recent command from said input device, the arrangement being such that the current transformation is regarded as having been completed when said elapsed time exceeds a predetermined value, wherein start of an alternative image draw operation by said engine is synchronized with the start of a new frame scan of said display screen, and said system being organized so as to permit a user to identify by means of a cursor symbol a graphics or like image on the screen for transformation, and to control said transformation interactively by means of the controlled movement of said cursor, across the screen whilst attached to said image, the arrangement being such that during transformation at least said graphics or like-image is replaced by an alternative image representing the graphics or like image on the screen but containing less detail to be drawn.
24. An interactive raster-scanned display system as claimed in claim 2 or claim 3, including means for monitoring the elapsed time from receipt by said microprocessor of the most recent command from said input device, the arrangement being such that the current transformation is regarded as having been completed when said elapsed time exceeds a predetermined value, wherein start of an alternative image draw operation by said engine is synchronized with the start of a new frame scan of said display screen, said system being organized so as to permit a user to identify by means of a cursor symbol a graphics or like image on the screen for transformation, and to control said transformation interac-tively by means of the controlled movement of said cursor, across the screen whilst attached to said image, the arrangement being such that during transformation at least said graphics or like-image is replaced by an alternative image representing the graphics or like image on the screen but containing less detail to be drawn, and wherein said cursor symbol is a full cross-hair symbol extending from screen edge to screen edge in both vertical and horizontal directions and during translation of said cursor symbol across the screen, whether attached to a graphics or like symbol or not, in response to commands from a cursor control input device operated by a user, is replaced by a relatively small cross-hair symbol containing considerably less detail.
25. An interactive raster-scanned display system as claimed in claim 2 or claim 3, including means for monitoring the elapsed time from receipt by said microprocessor of the most recent command from said input device, the arrangement being such that the current transformation is regarded as having been completed when said elapsed time exceeds a predetermined value, said full and alternative images are stored in the form of vector display lists in available allocated space in said random access, wherein start of an alternative image draw operation by said engine is synchronized with the start of a new frame scan of said display screen, said system being organized so as to permit a user to identify by means of a cursor symbol a graphics or like image on the screen for transformation, and to control said transformation interactively by means of the controlled movement of said cursor, across the screen whilst attached to said image, the arrangement being such that during transformation at least said graphics or like-image is replaced by an alternative image representing the graphics or like image on the screen but containing less detail to be drawn, and wherein said cursor symbol is a full cross-hair symbol extending from screen edge to screen edge in both vertical and horizontal directions and during translation of said cursor symbol across the screen, whether attached to a graphics or like symbol or not, in response to commands from a cursor control input device operated by a user, is replaced by a relatively small cross-hair symbol containing considerably less detail.
26. An interactive raster-scanned display system as claimed in claim 2 or claim 3, including means for monitoring the elapsed time from receipt by said microprocessor of the most recent command from said input device, the arrangement being such that the current transformation is regarded as having been completed when said elapsed time exceeds a predetermined value, said full and alternative images are stored in the form of vector display lists in available allocated space in said random access, wherein start of an alternative image draw operation by said engine is synchronized with the start of a new frame scan of said display screen, said system being organized so as to permit a user to identify by means of a cursor symbol a graphics or like image on the screen for transformation, and to control said transformation interactively by means of the controlled movement of said cursor, across the screen whilst attached to said image, the arrangement being such that during transformation at least said graphics or like-image is replaced by an alternative image representing the graphics or like image on the screen but containing less detail to be drawn.
27. An interactive raster-scanned display system as claimed in claim 2 or claim 3, including means for monitoring the elapsed time from receipt by said microprocessor of the most recent command from said input device, the arrangement being such that the current transformation is regarded as having been completed when said elapsed time exceeds a predetermined value, said full and alternative images are stored in the form of vector display lists in available allocated space in said random access, said control means includes a pointer mechanism arranged in operation to identify the location of a display list of a full image to be displayed and to identify the location of a display list of the associated alternative image upon invocation of transformation of said full image, wherein start of an alternative image draw operation by said engine is synchronized with the start of a new frame scan of said display screen, said system being organized so as to permit a user to identify by means of a cursor symbol a graphics or like image on the screen for transformation, and to control said transformation interactively by means of the controlled movement of said cursor, across the screen whilst attached to said image, the arrangement being such that during transformation at least said graphics or like-image is replaced by an alternative image representing the graphics or like image on the screen but containing less detail to be drawn.
28. An interactive raster-scanned display system as claimed in claim 2 or claim 3, including means for monitoring the elapsed time from receipt by said microprocessor of the most recent command from said input device, the arrangement being such that the current transformation is regarded as having been completed when said elapsed time exceeds a predetermined value, said full and alternative images are stored in the form of vector display lists in available allocated space in said random access, said control means includes a pointer mechanism arranged in operation to identify the location of a display list of a full image to be displayed and to identify the location of a display list of the associated alternative image upon invocation of transformation of said full image, wherein start of an alternative image draw operation by said engine is synchronized with the start of a new frame scan of said display screen, said system being organized so as to permit a user to identify by means of a cursor symbol a graphics or like image on the screen for transformation, and to control said transformation interactively by means of the controlled movement of said cursor, across the screen whilst attached to said image, the arrangement being such that during transformation at least said graphics or like-image is replaced by an alternative image representing the graphics or like image on the screen but containing less detail to be drawn, and wherein said cursor symbol is a full cross-hair symbol extending from screen edge to screen edge in both vertical and horizontal directions and during translation of said cursor symbol across the screen, whether attached to a graphics or like symbol or not, in response to commands from a cursor control input device operated by a user, is replaced by a relatively small cross-hair symbol containing considerably less detail.
29. An interactive raster-scanned display system as claimed in claim 2 or claim 3, including means for monitoring the elapsed time from receipt by said microprocessor of the most recent command from said input device, the arrangement being such that the current transformation is regarded as having been completed when said elapsed time exceeds a predetermined value, said full and alternative images are stored in the form of vector display lists in available allocated space in said random access, said full image is stored in said random access store as a vector display list ordered so as to be selected by said engine during a drawing operation in a predetermined sequence of vectors, said control means being arranged to be operable in response to receipt by said microprocessor of each transformation command from the input device to cause said engine to erase the image currently on display and to commence to re-draw said image from said ordered list incrementally transformed as required by said transformation command, the drawing operation continuing until receipt of a subsequent transformation command where upon the process is repeated, wherein start of an alternative image draw operation by said engine is synchronized with the start of a new frame scan of said display screen, said system being organized so as to permit a user to identify by means of a cursor symbol a graphics or like image on the screen for transformation, and to control said transformation interactively by means of the controlled movement of said cursor, across the screen whilst attached to said image, the arrangement being such that during transformation at least said graphics or like-image is replaced by an alternative image repre-senting the graphics or like image on the screen but containing less detail to be drawn.
30. An interactive raster-scanned display system as claimed in claim 2 or claim 3, including means for monitoring the elapsed time from receipt by said microprocessor of the most recent command from said input device, the arrangement being such that the current transformation is regarded as having been completed when said elapsed time exceeds a predetermined value, said full and alternative images are stored in the form of vector display lists in available allocated space in said random access, said full image is stored in said random access store as a vector display list ordered so as to be selected by said engine during a drawing operation in a predetermined sequence of vectors, said control means being arranged to be operable in response to receipt by said microprocessor of each transformation command from the input device to cause said engine to erase the image currently on display and to commence to re-draw said image from said ordered list incrementally transformed as required by said transformation command, the drawing operation continuing until receipt of a subsequent transformation command where upon the process is repeated, wherein start of an alternative image draw operation by said engine is synchronized with the start of a new frame scan of said display screen, said system being organized so as to permit a user to identify by means of a cursor symbol a graphics or like image on the screen for transformation, and to control said transformation interactively by means of the controlled movement of said cursor, across the screen whilst attached to said image, the arrangement being such that during transformation at least said graphics or like-image is replaced by an alternative image representing the graphics or like image on the screen but containing less detail to be drawn, and wherein said cursor symbol is a full cross-hair symbol extending from screen edge to screen edge in both vertical and horizontal directions and during translation of said cursor symbol across the screen, whether attached to a graphics or like symbol or not, in response to commands from a cursor control input device operated by a user, is replaced by a relatively small cross-hair symbol containing considerably less detail.
, 27
, 27
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP82306863.0 | 1982-12-22 | ||
| EP82306863A EP0112414B1 (en) | 1982-12-22 | 1982-12-22 | Image transformations on an interactive raster scan or matrix display |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1218774A true CA1218774A (en) | 1987-03-03 |
Family
ID=8189865
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000438411A Expired CA1218774A (en) | 1982-12-22 | 1983-10-05 | Image transformations on an interactive raster scan or matrix display |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US4688181A (en) |
| EP (1) | EP0112414B1 (en) |
| JP (1) | JPS59119476A (en) |
| CA (1) | CA1218774A (en) |
| DE (1) | DE3277247D1 (en) |
Families Citing this family (67)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3475661D1 (en) * | 1984-09-12 | 1989-01-19 | Ibm | Automatic highlighting in a raster graphics display system |
| JPH0772914B2 (en) * | 1985-08-21 | 1995-08-02 | カシオ計算機株式会社 | Graphic display device and graphic display method |
| JPS6284380A (en) * | 1985-10-09 | 1987-04-17 | Matsushita Electric Ind Co Ltd | Graphic editing device |
| JP2575636B2 (en) * | 1985-11-15 | 1997-01-29 | カシオ計算機株式会社 | Graphic display device |
| JP2679971B2 (en) * | 1985-11-15 | 1997-11-19 | カシオ計算機株式会社 | Graphic display control device |
| JPH07117886B2 (en) * | 1985-11-28 | 1995-12-18 | キヤノン株式会社 | Data control device |
| JPS62168271A (en) * | 1986-01-21 | 1987-07-24 | Ricoh Co Ltd | Graphic form producing device |
| JPS62179057A (en) * | 1986-01-31 | 1987-08-06 | Ricoh Co Ltd | Graphic generating and editing device |
| JPH0711752B2 (en) * | 1986-03-28 | 1995-02-08 | カシオ計算機株式会社 | Data movement editing method |
| JPH0640340B2 (en) * | 1986-07-31 | 1994-05-25 | 株式会社日立製作所 | Data display |
| SE8603442L (en) * | 1986-08-15 | 1988-02-16 | Ibm Svenska Ab | METHOD OF SCREEN PANEL TREATMENT |
| JPS6385977A (en) * | 1986-09-30 | 1988-04-16 | Canon Inc | Graphic editing device |
| US4731609A (en) * | 1986-11-03 | 1988-03-15 | International Business Machines Corporation | Fast correlation of markers with graphic entities |
| US5179656A (en) * | 1987-03-02 | 1993-01-12 | International Business Machines Corporation | Three dimensional directional pointer icon |
| GB8706348D0 (en) * | 1987-03-17 | 1987-04-23 | Quantel Ltd | Electronic image processing systems |
| US5379371A (en) * | 1987-10-09 | 1995-01-03 | Hitachi, Ltd. | Displaying method and apparatus for three-dimensional computer graphics |
| US4821211A (en) * | 1987-11-19 | 1989-04-11 | International Business Machines Corp. | Method of navigating among program menus using a graphical menu tree |
| US4918624A (en) * | 1988-02-05 | 1990-04-17 | The United States Of America As Represented By The United States Department Of Energy | Vector generator scan converter |
| JPH0228757A (en) * | 1988-07-18 | 1990-01-30 | Brother Ind Ltd | Document generating device |
| DE69033514D1 (en) * | 1989-02-08 | 2000-05-31 | Canon Kk | Figure processing device |
| JP2747055B2 (en) * | 1989-09-11 | 1998-05-06 | 株式会社日立製作所 | Graphic display device |
| JP2873840B2 (en) * | 1989-11-08 | 1999-03-24 | 日立ソフトウェアエンジニアリング株式会社 | Graphic processing unit |
| JPH03233689A (en) * | 1990-02-09 | 1991-10-17 | Fuji Xerox Co Ltd | Outline data drawing device |
| US5307452A (en) * | 1990-09-21 | 1994-04-26 | Pixar | Method and apparatus for creating, manipulating and displaying images |
| US5455902A (en) * | 1990-12-21 | 1995-10-03 | Eastman Kodak Company | Method and apparatus for performing real-time computer animation |
| US5214414A (en) * | 1991-04-12 | 1993-05-25 | International Business Machines Corp. | Cursor for lcd displays |
| EP0529121A1 (en) * | 1991-08-24 | 1993-03-03 | International Business Machines Corporation | Graphics display tool |
| JPH0581274A (en) * | 1991-09-20 | 1993-04-02 | Hitachi Ltd | Method for forming document |
| JPH05189535A (en) * | 1992-01-16 | 1993-07-30 | Fujitsu Ltd | Control system for graphic movement on display screen |
| US5448399A (en) * | 1992-03-13 | 1995-09-05 | Park Scientific Instruments | Optical system for scanning microscope |
| US5437009A (en) * | 1993-02-18 | 1995-07-25 | Bell Communications Research, Inc. | Method and system for displaying status information of communications networks |
| US5778401A (en) * | 1995-10-31 | 1998-07-07 | International Business Machines Corporation | Insertion bar |
| JP2794409B2 (en) * | 1996-06-21 | 1998-09-03 | セイコーエプソン株式会社 | Ruled line creation device |
| US20020154132A1 (en) | 1997-07-30 | 2002-10-24 | Alain M. Dumesny | Texture mapping 3d graphic objects |
| US6072498A (en) * | 1997-07-31 | 2000-06-06 | Autodesk, Inc. | User selectable adaptive degradation for interactive computer rendering system |
| US6321231B1 (en) | 1997-08-11 | 2001-11-20 | Marshall, O'toole, Gerstein, Murray & Borun | Data management and order delivery system |
| US6362817B1 (en) * | 1998-05-18 | 2002-03-26 | In3D Corporation | System for creating and viewing 3D environments using symbolic descriptors |
| US6559971B1 (en) * | 1998-10-27 | 2003-05-06 | Hewlett-Packard Development Co., L.P. | Self-resizing demonstration page for a printing device |
| US6310619B1 (en) | 1998-11-10 | 2001-10-30 | Robert W. Rice | Virtual reality, tissue-specific body model having user-variable tissue-specific attributes and a system and method for implementing the same |
| US6297799B1 (en) * | 1998-11-12 | 2001-10-02 | James Knittel | Three-dimensional cursor for a real-time volume rendering system |
| JP2002162958A (en) * | 2000-11-28 | 2002-06-07 | Pioneer Electronic Corp | Method and device for image display |
| CA2328795A1 (en) | 2000-12-19 | 2002-06-19 | Advanced Numerical Methods Ltd. | Applications and performance enhancements for detail-in-context viewing technology |
| CA2345803A1 (en) | 2001-05-03 | 2002-11-03 | Idelix Software Inc. | User interface elements for pliable display technology implementations |
| US8416266B2 (en) | 2001-05-03 | 2013-04-09 | Noregin Assetts N.V., L.L.C. | Interacting with detail-in-context presentations |
| US7213214B2 (en) | 2001-06-12 | 2007-05-01 | Idelix Software Inc. | Graphical user interface with zoom for detail-in-context presentations |
| US9760235B2 (en) | 2001-06-12 | 2017-09-12 | Callahan Cellular L.L.C. | Lens-defined adjustment of displays |
| US7084886B2 (en) | 2002-07-16 | 2006-08-01 | Idelix Software Inc. | Using detail-in-context lenses for accurate digital image cropping and measurement |
| US6847351B2 (en) * | 2001-08-13 | 2005-01-25 | Siemens Information And Communication Mobile, Llc | Tilt-based pointing for hand-held devices |
| CA2361341A1 (en) | 2001-11-07 | 2003-05-07 | Idelix Software Inc. | Use of detail-in-context presentation on stereoscopically paired images |
| CA2370752A1 (en) | 2002-02-05 | 2003-08-05 | Idelix Software Inc. | Fast rendering of pyramid lens distorted raster images |
| JP3833138B2 (en) * | 2002-04-19 | 2006-10-11 | キヤノン株式会社 | Image processing apparatus, image processing method, program, and storage medium |
| US8120624B2 (en) | 2002-07-16 | 2012-02-21 | Noregin Assets N.V. L.L.C. | Detail-in-context lenses for digital image cropping, measurement and online maps |
| CA2393887A1 (en) | 2002-07-17 | 2004-01-17 | Idelix Software Inc. | Enhancements to user interface for detail-in-context data presentation |
| CA2406131A1 (en) | 2002-09-30 | 2004-03-30 | Idelix Software Inc. | A graphical user interface using detail-in-context folding |
| CA2449888A1 (en) | 2003-11-17 | 2005-05-17 | Idelix Software Inc. | Navigating large images using detail-in-context fisheye rendering techniques |
| CA2411898A1 (en) | 2002-11-15 | 2004-05-15 | Idelix Software Inc. | A method and system for controlling access to detail-in-context presentations |
| US7486302B2 (en) | 2004-04-14 | 2009-02-03 | Noregin Assets N.V., L.L.C. | Fisheye lens graphical user interfaces |
| US8106927B2 (en) | 2004-05-28 | 2012-01-31 | Noregin Assets N.V., L.L.C. | Graphical user interfaces and occlusion prevention for fisheye lenses with line segment foci |
| US9317945B2 (en) | 2004-06-23 | 2016-04-19 | Callahan Cellular L.L.C. | Detail-in-context lenses for navigation |
| US7714859B2 (en) | 2004-09-03 | 2010-05-11 | Shoemaker Garth B D | Occlusion reduction and magnification for multidimensional data presentations |
| US7995078B2 (en) | 2004-09-29 | 2011-08-09 | Noregin Assets, N.V., L.L.C. | Compound lenses for multi-source data presentation |
| US7580036B2 (en) | 2005-04-13 | 2009-08-25 | Catherine Montagnese | Detail-in-context terrain displacement algorithm with optimizations |
| US8031206B2 (en) | 2005-10-12 | 2011-10-04 | Noregin Assets N.V., L.L.C. | Method and system for generating pyramid fisheye lens detail-in-context presentations |
| US7983473B2 (en) | 2006-04-11 | 2011-07-19 | Noregin Assets, N.V., L.L.C. | Transparency adjustment of a presentation |
| US9026938B2 (en) | 2007-07-26 | 2015-05-05 | Noregin Assets N.V., L.L.C. | Dynamic detail-in-context user interface for application access and content access on electronic displays |
| JP1617939S (en) | 2017-10-17 | 2018-11-12 | ||
| JP1617940S (en) | 2017-10-17 | 2018-11-12 |
Family Cites Families (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3723803A (en) * | 1970-07-06 | 1973-03-27 | Computer Image Corp | Generation, display and animation of two-dimensional figures |
| US4121228A (en) * | 1975-09-15 | 1978-10-17 | Cowe Alan B | Photocomposition machine with keyboard entry and CRT display |
| GB1570183A (en) * | 1976-01-21 | 1980-06-25 | Marconi Co Ltd | Position encoding arrangemnts |
| JPS5851273B2 (en) * | 1976-12-17 | 1983-11-15 | 株式会社日立製作所 | Cursor display signal generation method |
| US4125873A (en) * | 1977-06-29 | 1978-11-14 | International Business Machines Corporation | Display compressed image refresh system |
| GB2038596B (en) * | 1978-12-20 | 1982-12-08 | Ibm | Raster display apparatus |
| NO155164C (en) * | 1979-04-27 | 1987-02-18 | Furuno Electric Co | DEVICE FOR INDICATING A WALKING BODY 'S WAY. |
| GB2048624B (en) * | 1979-05-02 | 1982-12-15 | Ibm | Graphics display apparatus |
| US4254467A (en) * | 1979-06-04 | 1981-03-03 | Xerox Corporation | Vector to raster processor |
| DE2939489A1 (en) * | 1979-09-28 | 1981-05-14 | Siemens Ag | SYSTEM FOR LOCALIZING AREAS WITH MIXED TEXT / IMAGE EDITING ON THE SCREEN |
| US4282546A (en) * | 1979-11-28 | 1981-08-04 | Rca Corporation | Television image size altering apparatus |
| DE2952180A1 (en) * | 1979-12-22 | 1981-07-02 | Dornier System Gmbh, 7990 Friedrichshafen | DEVICE FOR OVERLAYING AND ACCURATE POSITIONING OR POINTLY SHIFTING OF SYNTHETICALLY GENERATED IMAGES |
| US4498079A (en) * | 1981-08-20 | 1985-02-05 | Bally Manufacturing Corporation | Prioritized overlay of foreground objects line buffer system for a video display system |
| US4454507A (en) * | 1982-01-04 | 1984-06-12 | General Electric Company | Real-time cursor generator |
| US4561659A (en) * | 1983-01-06 | 1985-12-31 | Commodore Business Machines, Inc. | Display logic circuit for multiple object priority |
| US4542376A (en) * | 1983-11-03 | 1985-09-17 | Burroughs Corporation | System for electronically displaying portions of several different images on a CRT screen through respective prioritized viewports |
| US4613946A (en) * | 1984-06-07 | 1986-09-23 | Forman Ernest H | Method and apparatus for generating hierarchical displays |
-
1982
- 1982-12-22 DE DE8282306863T patent/DE3277247D1/en not_active Expired
- 1982-12-22 EP EP82306863A patent/EP0112414B1/en not_active Expired
-
1983
- 1983-10-05 CA CA000438411A patent/CA1218774A/en not_active Expired
- 1983-10-11 JP JP58188594A patent/JPS59119476A/en active Granted
-
1986
- 1986-04-30 US US06/859,845 patent/US4688181A/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| US4688181A (en) | 1987-08-18 |
| EP0112414A1 (en) | 1984-07-04 |
| JPS6310470B2 (en) | 1988-03-07 |
| JPS59119476A (en) | 1984-07-10 |
| DE3277247D1 (en) | 1987-10-15 |
| EP0112414B1 (en) | 1987-09-09 |
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