Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUSRE43462 E1
Publication typeGrant
Application numberUS 09/301,656
Publication dateJun 12, 2012
Filing dateApr 28, 1999
Priority dateApr 21, 1993
Publication number09301656, 301656, US RE43462 E1, US RE43462E1, US-E1-RE43462, USRE43462 E1, USRE43462E1
InventorsKinya Washino, Barry H. Schwab
Original AssigneeKinya (Ken) Washino
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Video monitoring and conferencing system
US RE43462 E1
Abstract
A PC-based system for monitoring and storing representative images from video cameras may be utilized for security or other monitoring applications. Camera inputs from digital or analog sources are individually and independently digitized and displayed at a first set of image sizes, sampling rates, and frame rates, and may be stored in digital form on various recording media at a second set of image sizes, sampling rates, and frame rates, and these two sets of sizes and rates may or may not be identical. Provisions are included for adding detection or alarm systems which will automatically alter image size, sampling rate and/or frame rate of an individual input source, or activate other physical responses. In addition to security system monitoring, further applications of the invention are disclosed for process monitoring in manufacturing environments and also for applications in videoconferencing.
Images(9)
Previous page
Next page
Claims(41)
1. A video storage and display system, comprising:
a plurality ofone or more video cameras, each outputting a signal representative of a video image;
means to receive the signals from each camera and digitally compress the images;
two forms of high-capacity storage media, one being randomly searchable while the other continues to store the digitally compressed image; and
a computer configured to receive the digitally compressed images, the computer being interfaced to the following devices:
a display screen,
means to receive externally derived operator commands, and
the high-capacity storage media, and wherein the computer is programmed to perform the following functions:
display the digitally compressed images from the cameras in different windows on the display screen, each window being associated with an update rate and dimensions in pixels,
vary the dimensions and the ratespatial parameters and temporal parameters at which a particular image is updated in its window in accordance with one of the externally derived commands,
store the digitally compressed images in the high-capacity storage mediummedia, and
vary the dimensions and the ratespatial parameters and temporal parameters at which a particular image is stored in accordance with one of the externally derived commands.
2. The video storage and display system of claim 1, further including means associated with the computer for controlling the operation of one or more of the video cameras.
3. The video storage and display system of claim 1, wherein the means to digitally compress the image from a particular camera is disposed at the location of the camera.
4. The video storage and display system of claim 1, wherein the means to digitally compress the image from a particular camera is disposed at the location of the computer.
5. The video storage and display system of claim 1, further including a separate computer associated with each camera, the computers being networked together over a common communication bus, enabling an operator situated at a particular computer to display the images gathered by other cameras in separate windows on that operator's display screen.
6. The video storage and display system of claim 1, wherein one or both of the high-capacity storage mediummedia comprises a magnetic tape.
7. The video storage and display system of claim 1, wherein one or both of the high-capacity storage mediummedia comprises a magnetic disk.
8. The method of simultaneously displaying and storing multiple video images, comprising the steps of:
receiving video images from a plurality of sources;
digitizing one or more of the images if not already in digital form;
displaying at least certain of the digitized images in separate windows on a display device, using a first, predetermined frame rate and resolution associated with each window; and
simultaneously storing the displayed images using a second, predetermined frame rate and resolution associated with each image.
9. The method of claim 812, further including the step of receiving a command to set the frame rate and resolution associated with the display and storage of a particular image.
10. The method of claim 9, wherein the command is based upon an operator input.
11. The method of claim 9, wherein the command is based upon an external stimulus.
12. The method of simultaneously displaying and storing multiple video images, comprising the steps of:
receiving video images at a personal computer based system from a plurality ofone or more sources;
digitizing one or moreany of the images if not already in digital form using an analog-to-digital converter;
displaying at least certain of the digitized images in separate windows on a personal computer based display device, using a first set of temporal and spatial parameters associated with each image in each window;
simultaneously storing the displayed imagesconverting one or more of the video source images into a data storage format using a second set of temporal and spatial parameters associated with each image; and
simultaneously storing the converted images in a storage device.
13. The method of claim 12, the temporal parameters including frame rate.
14. The method of claim 12, the spatial parameters including image dimension in pixels.
15. A video storage and display system, comprising:
a plurality ofone or more video cameras, each outputting a signal representative of a video image;
means to receive the signals from each camera and digitally compress the images; and
a computer configured to receive the digitally compressed images, the computer being interfaced to the following devices:
a display screen,
means to receive externally derived operator commands including means for sensing a deviation from the normal-state image scene associated with at least one of the video cameras, the existence of the deviation being used as the basis for generating an externally derived command, and
a high-capacity storage medium, and programmed to perform the following functions:
display the digitally compressed images from the cameras in different windows on the display screen, each window being associated with an update rate and dimensions in pixels,
vary the dimensions and the ratespatial parameters and temporal parameters at which a particular image is updated in its window in accordance with one of the externally derived commands,
store the digitally compressed images in the high-capacity storage medium, and
vary the dimensions and the ratespatial parameters and temporal parameters at which a particular image is stored in accordance with one of the externally derived commands.
16. The video storage and display system of claim 1, wherein one or more video images or camera control signals are received through a network connection.
17. The video storage and display system of claim 1, wherein one or more of the high-capacity storage media comprises a removable or permanent magnetic disk, a removable or permanent magneto-optical disc, a removable optical disc or a removable or permanent semiconductor-based device.
18. The video storage and display system of claim 1, wherein the temporal parameters include frame rate and the spatial parameters include image dimension in pixels.
19. The method of claim 12, wherein one or more video images or camera control signals are received through a network connection.
20. The method of claim 12, wherein the high-capacity storage medium comprises a removable or permanent magnetic disk, a removable or permanent magneto-optical disc, a removable optical disc or a removable or permanent semiconductor-based device.
21. The method of claim 12, including a display device associated with each source and a communication capability enabling an operator situated at the display for one source to view images, in separate windows, gathered by one or more different source.
22. The video storage and display system of claim 15, further including a device for remotely controlling the operation of one or more of the video cameras.
23. The video storage and display system of claim 15, wherein one or more video images or camera control signals are received through a network connection.
24. The video storage and display system of claim 15, wherein the high-capacity storage medium comprises a removable or permanent magnetic disk, a removable or permanent magneto-optical disc, a removable optical disc or a removable or permanent semiconductor-based device.
25. The video storage and display system of claim 15, further including a memory for storing the sensed deviation information in conjunction with the image data.
26. The video storage and display system of claim 15, further including:
a computer and display device associated with each video camera; and
communication capability enabling an operator situated at the display device associated with one camera to view images, in separate windows, gathered by one or more different cameras.
27. The video storage and display system of claim 15, wherein the temporal parameters include frame rate and the spatial parameters include image dimension in pixels.
28. A video storage system, comprising:
one or more video sources, each outputting a signal representative of a video image;
means to receive the signals from each source and digitally compress the images;
two forms of a high-capacity video storage media; and
a computer interfaced to the following devices:
an input to receive externally derived operator commands, and
the high-capacity storage media, and
wherein the computer is programmed to perform the following functions:
store the digitally compressed images in the high-capacity storage media, and
vary the spatial parameters and temporal parameters at which a particular image is stored in accordance with one of the externally derived commands.
29. The video storage system of claim 28, wherein the high-capacity storage media include one medium being randomly searchable, and with the other being serially searchable.
30. The video storage system of claim 28, wherein one or more video images is received through a network connection.
31. The video storage system of claim 28, wherein the high-capacity storage media comprises a removable or permanent magnetic disk, a removable or permanent magneto-optical disc, a removable optical disc or a removable or permanent semiconductor-based device.
32. The video storage system of claim 28, wherein the temporal parameters include frame rate and the spatial parameters include image dimension in pixels.
33. A digital video recording and monitoring system configured for use with a display device, comprising:
one or more inputs for receiving video material characterized by having spatial parameters and temporal parameters;
circuitry for digitally compressing the video material;
a first video storage medium which is randomly addressable;
a second video storage medium which is serially addressable;
an output for delivering the video material to the display device;
a user control; and
processing hardware or software operative to perform the following functions under user control:
a) store the digitally compressed video material in one or both of the first and second video storage media, and
b) output the video material for monitoring to the display device.
34. The digital video recording and monitoring system of claim 33, wherein the processing circuitry is operative to simultaneously store the digitally compressed video material in the first and second video storage media.
35. The digital video recording and monitoring system of claim 33, wherein the first video storage medium is a magnetic disk.
36. The digital video recording and monitoring system of claim 33, wherein the second video storage medium is a magnetic tape.
37. The digital video recording and monitoring system of claim 33, wherein the processing circuitry further permits searching of the video material previously recorded on the first storage medium while continuing to store the material on the second storage medium.
38. The digital video recording and monitoring system of claim 33, wherein the spatial parameters and temporal parameters of the video material in the first or second storage medium are different from the spatial parameters and temporal parameters of the video material delivered to the display device.
39. The digital video recording and monitoring system of claim 33, further including one or more video cameras interfaced to the one or more inputs.
40. The digital video recording and monitoring system of claim 33, further including:
a plurality of video cameras interfaced to the one or more inputs; and
the video material from different cameras is visible in different windows on the display device.
41. The digital video recording and monitoring system of claim 33, wherein the temporal parameters include frame rate and the spatial parameters include image dimension in pixels.
Description
REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. Ser. No. 08/050,861, filed Apr. 21, 1993 now U.S. Pat. No. 5,450,140 and Ser. No. 08/298,104, filed Aug. 30, 1994 now U.S. Pat. No. 5,537,157.

FIELD OF THE INVENTION

This invention relates generally to video monitoring, and, more particularly, to such systems employing means for digitizing camera images for display at a first image size, sampling rate, and frame rate, and for digital storage at a second image size, sampling rate, and frame rate.

BACKGROUND OF THE INVENTION

Existing systems for monitoring video signals from multiple sources either have relied upon switching means to sequence through each of the sources in a predetermined pattern, or else implement some form of “split screen” display, in which a conventional video monitor displays, for example, the output of four cameras, each occupying a portion of the display screen. Often, the video output is also supplied to signal storage means such as a VCR which is operated in a single-frame recording mode, providing a time-lapse record of the camera outputs. These types of systems are in common usage, and are well known in the art.

More recently, the availability of digital techniques for video signal processing and data compression has opened new video monitoring alternatives. Mathisen, for example, U.S. Pat. No. 4,198,656, describes a system employing a signal selector which is controlled by signal storage means, including a VCR functioning as a time-lapse frame recorder, and disc storage means functioning as a frame-store type device which provides continuity in the display while the selector is advancing through its sequence to the next signal source, or to the next recorded signal from one particular source. Each image is further provided with a digital code, which enables the image source to be identified upon playback.

Katz (U.S. Pat. No. 5,216,502) discloses a system for monitoring and recording transactions at multiple cashier lanes. According to the preferred embodiment, output signals from four cameras are fed to a four-quadrant multiplexer, which contains a frame store having provisions for reducing each camera image to one-quarter size and then displaying it in one of the four quadrants of the video monitor. The combined output signal is then recorded on a Video Cassette Recorder (VCR) to provide a more permanent record of the transaction. No description is given of the size-reduction method, but this kind of display may be implemented by employing a time-compression scheme for the horizontal lines, and eliminating alternate scan lines from the vertical dimension of the video frame. Data from the individual cash registers is encoded digitally, and then either recorded on lines of video in the vertical-interval or else recorded on the audio tracks of the VCR. The monitoring provisions include a video overlay generator, so that transaction information may be displayed concurrently with images of the event. Provisions are also included for selective recording of representative frames of video, as triggered by transaction events at individual cashier lanes. This further reduces the number of frames recorded, and extends the recording duration of the video cassette.

Neither of these two inventions disclose the use of image data compression schemes, nor of image resizing by digital means. Katz does disclose selective recording of frames of video, but only in analog form, and using conventional video recording means, such as a VCR.

Blum et al. (U.S. Pat. No. 5,237,408) disclose a system employing multiple interface circuit boards containing provisions for capturing and digitizing images from a plurality of cameras, further storing a slow-scan sequence of images for each camera in active buffer memory means as RAM on each of the interface boards. The display of these image sequences is preferably controlled by a PC with disk storage capabilities, and individual images selectively may be recorded on the hard disk, under operator control. Storage capacity is limited, however, because no image data compression is provided, and it is not practical to store large quantities or sequences of images. There are no provisions for automatic recording of images, nor any provision for storing these images in a data form differing from the display format image size.

Gormley (U.S. Pat. No. 5,258,837) discloses video compression means as a method for fitting multiple camera images within a single video display screen. However, Gormley clearly indicates that the system relies on fixed image-size compression of the digitized incoming video signal, and does not perform any kind of bandwidth compression. Provisions are included for storing images on a video recorder, but, as in other systems, these images are stored by taking the screen display as a whole, rather than storing independently constituted representations of the individual camera outputs.

In general, these conventional systems, regardless of the subsequent signal processing employed, accept analog video signals from the camera sources for input to the monitoring system. As such, these signals are susceptible to disturbances such as RF interference, ground-loop noise, and high-frequency signal loss due to long runs of coaxial cables. Automatic video switcher units sequence the source signals at a relatively slow rate, requiring as much as 16 seconds delay between successive viewings of a particular source when using a one source-per-second rate to sequence through 16 sources. When such a system is equipped with a time-lapse video recorder, the recording medium is expensive, has low resolution, and is limited in recording capacity.

Other systems, such as video conferencing arrangements, use multiple camera images and audio sources which are coordinated through electronic switching means and image display means, with interconnections between conferencing rooms locally or at remote sites via telephone lines or other communications links. Fabris et al. (U.S. Pat. No. 4,516,156) discloses a sophisticated implementation of such a system, employing satellite links for long-distance communications, a full range of camera remote controls (including lens controls and pan-tilt-head controls), and touch-screen monitor facilities for system controls of cameras and signal switching. This system, however, has no provisions for image storage, or any application of image data compression means coupled with display means or image storage means.

SUMMARY OF THE INVENTION

The present invention implements an automated video monitoring system by way of a PC-based platform employing display windowing software, with camera sources being interfaced to an input circuit board which includes provisions for image data compression. Using a basic image size in pixels of 320×240, and optionally including color processing employing a Y-U-V 4:1:1 or 4:2:2 sampling technique, a range of performance standards are established. An economical simultaneous display of 4 sources in a 2×2 configuration on a conventional 10″ VGA-format (640×480 pixels) monitor may be upgraded to a more elaborate 24-source (plus one utility window, which also may be used as a graphical-based input source device for transmitting control commands to the individual cameras) display in a 5×5 configuration on a high-resolution 20″ (1600×1200 pixels) monitor. Other combinations are possible, including arrays of images of size 640×480 pixels or even 800×600 pixels, depending on the screen size of the display monitor and the capabilities of the video display adapter circuit card. In addition, not all image windows need to be of the same size, nor updated at the same rate, but rather they may be mixed and combined based on particular applications. Remote controls for the individual cameras may be implemented by way of windowing software and/or monitor touch-screen devices. Automatic sensing of particular events (representing security alarms, equipment or process disturbances, or a change in the person speaking in a videoconferencing environment) may be employed to cause reconfiguration by way of resizing the image or modifying the update rate of individual windows on the display screen, or by modifying the data format of recording images on a storage device.

Storage of images may be implemented by way of a tape back-up device, such as a DAT or 8-mm tape recorder, which are capable of storing as much as 960 hours of monitoring images, or by way of disk storage devices, preferably including removable disk drives such as magneto-optical disks or PCMCIA-compatible disk-drive modules. Images are preferably stored as a succession of data-compressed representations, corresponding to various window sizes sampled at diverse update rates; however, though the image representations need not be identical to the sizes and rates used for video monitors displaying the various images. In an alternative embodiment, cameras are provided with data compression means at the camera location, with a bi-directional data link providing control signals from the PC, and accepting data-compressed images from the cameras. Depending on the data rates selected, the transmission of these signals may be by means of coaxial cables, twisted-pair lines, or fiber-optic cables. These signals may alternatively be transmitted over internal PBX telephone lines, or over greater distances, including satellite links, as would be the case for remote monitoring of facilities or videoconferencing. The use of digital images allows the application of various useful techniques, such as digital noise reduction and motion-sensing, to trigger security alarms, for example.

It is an object of the invention to provide a more efficient method for monitoring camera outputs by means of a multiple-window display system implemented on a computer platform.

It is another object of the invention to provide an improved recording system for event-logging or security applications, by means of storing data-compressed digital images, including identifying information, which are more representative of events than typical analog time-lapse recordings, and further to implement this system on a computer platform.

It is a further object of the invention to provide extended recording time for event-logging or security applications by means of either tape-based, or disk-based, or both tape-based and disk-based data recording means.

It is yet another object of the invention to provide a system for remote monitoring of cameras by means of transmission of data-compressed digital images over communication links.

It is yet a further object of the invention to provide a convenient method of implementing videoconferencing facilities by means of a PC-based platform.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1-6 show various possible screen display configurations according to the invention;

FIG. 7 is a functional diagram of a PC-based system wherein plug-in printed-circuit boards implement digital processing for analog input signals;

FIG. 8 is a functional diagram of a plug-in printed-circuit board introduced with reference to FIG. 7;

FIG. 9 is a functional diagram of a universal camera adapter having digital output signals;

FIG. 10 is a diagram of an integrated camera system;

FIG. 11 is a functional diagram of a PC-based monitoring system adapted for videoconferencing at multiple remote locations;

FIG. 12 is an overhead view of a physical layout of the system of FIG. 11;

FIGS. 13A and 13B are drawings of a multiple-camera monitoring unit for table-top use in videoconferencing;

FIG. 14 is a side-view of an expanded multiple-camera monitoring unit implemented for videoconferencing;

FIG. 15 is a table listing a variety of possible operating modes, depending on computer monitor display facilities, in either a monitoring or a videoconferencing version of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention implements an automated video monitoring system by way of a PC-based platform employing display windowing software, with camera sources being interfaced to an input circuit board which includes provisions for image data compression. The basic video window size of 320×240 pixels from each camera source can be displayed on a variety of video monitors, in a number of formats, depending on system complexity. The preferred recording medium is a 4-mm helical-scan data cartridge, commonly referred to as a digital audio tape (DAT). Each tape cartridge is capable of storing 10 GB (gigabytes) of data. All recording times in the explanation below are based a data-compression ratio of 100:1, utilizing a 4:2:2 Y/U/V sampling method for color images. Other higher capacity media, such as 8-mm tapes capable of 20 GB of data storage, may be employed when longer times are desired.

FIG. 15 shows a variety of possible operating modes, depending on the particular implementation of the PC-based monitoring system. These six representative modes will be explained in detail with the understanding that the invention is by no means limited to the specific examples shown, and that many different alternatives are possible. It should be noted also that in certain of the implementations shown, the entire screen may not be occupied by the various windows, and any unused areas at the top, bottom, or sides may be utilized to display warning messages, control buttons, or other such facilities.

FIG. 1 shows a computer monitor display for a system configured in accordance with Mode I as listed in FIG. 15. Using a commonly available 14″ VGA-format computer monitor with a dimension in pixels of 640×480, four windows having a dimension in pixels of 320×240 may be displayed simultaneously. Recording this data at the rate of one frame per second (1 fps) in black and white (B/W) and with 100:1 data-compression on a 10 GB DAT tape provides approximately 960 hours of images per tape, or alternatively more than 480 hours of color images. A second monitor optionally may be used to display utility windows including various system operating controls, as, for example, camera pan, tilt, zoom, focus, and so forth.

FIG. 2 shows a computer monitor display for a system configured in accordance with Mode II as listed in FIG. 15. Using a 15″ to 17″ SVGA-format computer monitor with a dimension in pixels of 1024×768, nine windows, each having a dimension in pixels of 320×240, may be displayed simultaneously. Eight windows may be implemented as camera displays, and the ninth window may be used for the continuous display of the utility window, as described above. Recording of all eight windows at 1 fps will allow 480 hours of B/W images in this configuration per 10 GB DAT tape, or alternatively more than 240 hours of color images.

FIG. 3 shows a computer monitor display for a system configured in accordance with Mode III as listed in FIG. 15. Using a 17″ to 20″ high-resolution computer monitor with a dimension in pixels of 1240×1024, eight windows having a dimension in pixels of 320×240 may be displayed, in addition to two windows having a dimension in pixels of 640×480. One of these larger windows may be implemented as a utility window, and the other larger window may be implemented for sequential display of the eight camera inputs at full camera resolution having a dimension in pixels of 640×480. Recording all eight camera image windows, and also the input-scan window, at 1 fps will allow 360 hours of B/W images in this configuration per 10 GB DAT tape, or alternatively more than 180 hours of images in color.

FIG. 4 shows a computer monitor display for a system configured in accordance with Mode IV as listed in FIG. 15. Using a 20″ high-resolution computer monitor with a dimension in pixels of 1600×1200, 25 windows with a dimension in pixels of 320×240 may be displayed simultaneously. Twenty-four windows may be implemented as camera displays, and one is implemented as a the utility window. Recording all twenty-four windows, and also the utility window, at 1 fps will allow 180 hours of B/W images in this configuration per 10 GB DAT tape. If color recording is desired, a 20 GB 8-mm data cartridge will allow 180 hours of color images.

FIG. 5 shows a computer monitor display for a system configured in accordance with Mode V as listed in FIG. 15. Using a 20″ high-resolution computer monitor with a dimension in pixels of 1600×1200, twelve larger windows having a dimension in pixels of 400×300 may be displayed, as well as one large high-resolution window, with a dimension in pixels of 800×600, to display the sequentially scanned output of the camera images. Recording in this format at 1 fps will provide 180 hours of B/W images in this configuration per 10 GB DAT tape. If color recording is desired, a 20 GB 8-mm data cartridge will allow 180 hours of color images.

FIG. 6 shows a computer monitor display for a system configured in accordance with Mode VI as listed in FIG. 15. Using a 14″ to 17″ SVGA computer monitor with a dimension in pixels of 1240×1024, and implementing a smaller window size with a dimension in pixels of 240×180, eight windows are available for the camera image displays, and two large windows of 480×360 are available for sequentially-scanned camera images. Recording in this screen format at 1 fps allows 480 hours of B/W images in this configuration on a 20 GB 8-mm data cartridge, and allows 240 hours of images in color.

In any of the display configurations just described, it is also possible to use a video overlay technique to display the utility controls superimposed on the camera video. Regardless of which display or recording format is used, the PC based monitoring system includes various facilities and features, which will now be described in further detail.

In operation, the user need only observe the various display windows on the monitor screen, rather than concentrate on many monitors simultaneously, thereby reducing the risk of missing an important event. Since no video switcher is used in recording, and images from all sources are continuously recorded at the selected frame rate for each source, more information is recorded than in conventional analog systems, wherein events may be missed due to the sequential switching of input images. The digital format also improves the picture quality, as the signal-to-noise ratio will be higher than for analog systems. In addition, there is no loss of quality during recording or playback, and because the recording technique is digital, other types of information optionally may be recorded along with the camera data, such as audio, time, date, location, etc.

An additional feature is the capability to implement a dual-recording-media option. This facility provides the ability to record simultaneously both on a tape (for high capacity, long term storage) and also on a removable media, such as a removable hard disk (i.e. PCMCIA) or magneto-optical disk (for short-term storage of up to 24 hours of images). These disks facilitate high-speed searching of recorded information without interrupting the tape, as well as providing a back up for the recording on the tape. In addition, the system is capable of simultaneously searching the recorded images on the disk storage unit while continuing to store images on the tape storage unit.

It should be noted that there is no requirement that the image sizes or frame rates utilized for the video display match those utilized for the storage media. In practice, these two specifications may not agree, and will be determined by other factors, such as operator manipulation of the displayed image sizes or changes resulting from the detection of alarm conditions.

FIG. 7 shows a functional diagram of an analog input-digital processing card installed in the PC which allows the use of existing analog cameras and cables with the PC-based monitoring system. This card, which may be obtained from such manufacturers as Nova, Model No. V-SW, features four video inputs 2a-2d having balanced or differential input circuitry for good noise immunity (or optically-coupled inputs for fiber-optic cabling), four video amplifiers 4a-4d, a 4×1 video switcher 6 by which any one of the four video inputs may be selected as a signal source, and an analog-to-digital (A/D) converter 8. The recording of camera inputs is digital, however, there is no provision for remote control of camera functions such as pan, tilt, zoom, and so forth. If additional inputs are desired, multiple cards may be installed in the PC. The output of the A/D converter 8 is supplied to the graphics processor and image data-compression engine 10. This unit performs the various functions required to configure the image sizes and frame rates as specified by the equipment operator. Because the overall data recording bandwidth of the system is a factor in the selection of the individual picture data rates, computer software is provided to implement menu-driven management of the data bandwidth allocation to the various image sources. Based on this configuration, signals are provided to the video switcher 4 to facilitate the selection of the particular image sources as required. The data-compressed images are provided in digital form to the microprocessor data bus 12. The microprocessor unit (not shown) in turn provides control signals to the graphics processor 10 by way of this data bus, in accordance with the image data allocation configuration selected.

FIG. 8 is a functional diagram of a digital input/output-digital processing card which implements bi-directional digital communications to and from the camera/adapter unit over a single transmission line, thereby greatly reducing the cost of cable and installation, and allowing existing wiring to be used. Various implementations of this printed-circuit card are required, depending on the type of network interconnection media selected. In addition, system performance will depend on the type of network interconnection media. As an example, a fiber optic network will have a higher transmission rate and better signal quality than a telephone network. Interfacing technology for these communication methods are in common usage and well known in the art. This printed-circuit card also serves four cameras through inputs 52a-52d, and additional cards can be implemented if required. The bi-directional digital video and camera control data switcher 54 serves to select the individual image sources as explained in reference to FIG. 7. These source signals are then provided to the graphics processor and image data-compression engine 56, which provides similar functions to those provided by the graphics processor 10, discussed in reference to FIG. 7. The processed data-compressed images are then provided to the microprocessor data bus 60. However, in this implementation, the bi-directional nature of the data switcher 54 is exploited to provide full functional control of the camera facilities through the bi-directional controller 58. These functional controls include the cameras themselves (lens and exposure control) and the camera's physical mounting provisions (pan and tilt). The various control signals for these functions are those traditionally provided to these kinds of equipment, and these concepts are well known in the art. In an alternative embodiment, the individual cameras are each equipped with separate image data-compression facilities, utilizing such techniques as motion-JPEG or MPEG compression. In this case, control signals for these additional functions are provided from the microprocessor bus 60 through the bi-directional controller 58 and the data switcher 54.

FIG. 9 is a functional diagram of a digital output universal camera adapter. This is a fully digital version of the camera adapter as described in co-pending U.S. patent application Ser. No. 08/050,861, titled “PERSONAL-COMPUTER BASED VIDEO PRODUCTION SYSTEM” now U.S. Pat. No. 5,450,140. The A/D-converter, digital image data-compressor, and bi-directional interface camera adapter 100 accepts analog audio and video signals from the camera 102, and converts them to digital signals in anticipation of the transmission of these signals over the interconnection network 104. The camera adapter also receives camera control commands from the PC by means of the interconnection network, and translates them into the appropriate pan, tilt, zoom, focus and iris control signals for the particular camera equipment, including the camera lens 106 and the pan/tilt mounting facilities 108. In addition, the camera adapter also has inputs for several “alarm system” type sensors 110, as, for example, motion detectors, photocell detectors, or simple switches. These alarm signals are digitized, encoded, and then transmitted to the main PC by means of the interconnection,networkinterconnection network. Power is supplied for this equipment from a local source 112. This camera adapter is implemented to provide a full-function system, adaptable to all existing types of cameras and control equipment. However, because of the large number of interconnections involved in the adapter, camera, pan/tilt unit, and sensors, the installation process may be somewhat complicated.

By equipping an individual camera input with digital frame store capabilities, it is possible to detect an alarm condition based on deviations from the normal-state image scene. For example, if a camera is monitoring a door exit or an area of a warehouse aisle that is not utilized during evening hours, any change in the image would represent an alarm condition. To allow camera movement, this sensing process would be disabled during pan, scan, tilt, zoom, and other camera positioning controls, and the sensing would be re-enabled after camera positioning ceased, or by manual operator control.

FIG. 10 is a functional diagram of an integrated camera system according to the invention including means to overcome problems associated with having a physically separate camera, pan/tilt unit, and adapter unit. The integrated system includes a camera 150 with pan/tilt control, A/D converter, digital data-compression circuitry, and requisite interfacing circuitry. Such provisions are preferably included in the camera base structure 152, which simplifies installation, as no separate interconnecting cables are required. The integrated camera system optionally may include provisions for supplying electrical operating power from a network coaxial cable, and thereby may be implemented with only a single interconnecting cable. An integrated camera system of this type may be implemented in a physical package which is as small as the camera itself, since most of the electronics may be highly miniaturized by developing custom integrated circuits, including LSI, ASIC, DSP, and mixed-signal processing.

It will be appreciated that in any of these implementations, alarm or sensor signals may be utilized to automatically re-configure the system operating mode, as, for example, increasing the frame rate or image size for an image source associated with the sensor which has initiated the alarm signal condition. As explained above, the displayed windows and image sizes may be reconfigured into an operating mode different from the reconfiguration of the digital storage mode. If desired, the operator may choose to allow the system to automatically adjust the compression ratio utilized for a particular window in response to alarm signal conditions. Alternatively, the compression ratio may be adjusted in response to the selection by the operator of a particular window for closer monitoring, by switching to an image window having larger dimensions in pixels. For some applications, the use of a resolution-independent data compression scheme, such as the “Fractal Compression” method of Iterated Systems, Inc., will be preferred, since images compressed by this method may be resized to fit larger or smaller windows as desired, without loss of apparent resolution. In addition, automatic switching of the audio signals associated with a particular window in response to alarm signal condition will enable the operator to fully investigate such events, and the audio signals may serve to attract the operate's attention to the event. Such switching optionally may be coupled with operator selections for monitoring purposes as well, and in both of these options may be integrated into the system previously described for recording the images, with or without any associated audio signals, onto the mass-storage media.

FIG. 11 illustrates a PC-based monitoring system implemented for videoconferencing at multiple remote locations. In this application of the invention, a main control center, shown generally as 200, is interconnected, by way of a network, with remote locations, shown generally as 204 to 210, designated as “1” through “N”. The network 202 may be implemented by way of telephone lines (slow speed), ISDN Lines (medium speed), or alternatively coaxial cable or fiber optics cables (high speed). The higher speed implementations permit transmission at higher frame rates and higher image resolutions. As an alternative, wireless networks or microwave links optionally may be used. Network communication between the main and remote locations is bi-directional; the main computer receives audio, video, and sensor data from each of the remote locations, and transmits controls for camera pan, tilt, focus, zoom, and so forth. Audio and video communications for the system operators also is provided, by means of an additional camera and headset at each location.

The application of these PC-based monitoring techniques also may hebe implemented in cases in which the central monitoring area may be located at some distance from the remote site. In this case, the physical hardware and networking facilities will follow the example shown in FIG. 11, with the understanding that “Location 1” through “Location IN” will now refer to separate monitoring for security applications or other monitoring purposes.

The purpose of the main control center is to manage multiple cameras at multiple locations. By monitoring and controlling the remote locations from a central location 220, the system may function without an operator at each location. Optionally, additional computers shown, by way of example, as 222 and 224 at the main location may be implemented to simplify the monitoring and control of the remote locations. The main control center stores the data from remote locations in the main control storage facilities, shown, by way of example, as 238, 240 and 242, using digital tape and removable media, including, by way of example, PCMCIA-based removable media or magneto-optical (MO) media. The images may be stored at various frame rates and resolutions, depending on the requirements for the intended use of the stored images. Intercom provisions as shown as 230, 232 and 234, facilitate the coordination of activities between the main control center and the various remote locations, and video camera units are provided at each of the computers, shown, by way of example, as 244, 246 and 248.

Each remote location includes a PC/monitor 250, with multiple video cameras, shown, by way of example, as 252 and 254, including provisions 256 for image and data storage utilizing digital tape and other removable media. This remote location may be operated under control from either the main location (as described above), or a local operator, or by specific software designed for automatic control. In the case of software-controlled operations, provisions are included for control to be assumed by the main control center, if necessary. As in the case of the main control computers, each of the remote computers is equipped with intercom facilities as 258 and video cameras as 260.

In the traditional videoconferencing situation, only one camera and monitor are used. Unfortunately, this results in an unnatural scene which provides the users with only a single viewing perspective. The use of a wide-angle camera lens which is needed to include many people seated around a table creates a distorted view, especially for those seated furthest from the camera. FIG. 12 shows an overhead view of the typical videoconferencing arrangement, including conference table 300, camera and monitor 302, and conference participants, shown as circles as 304.

Using the PC-based monitoring system, it is possible to create a video conference that presents a much more natural viewing appearance. As shown in FIG. 13A, a multiple-camera, multiple-display unit 310 preferably is preferably located directly on the conference table 312. This reduces the camera-perspective-distorting effects just described, because conference members 314 may be seated in a more comfortable and convenient position. The resulting video image is also much more natural. Each controller remote site computer-display section 322 (as described herein below) simultaneously shows all of the members participating in the remote conference, with an individual video window allocated for each participant, under control from the PC-based monitoring system operator. In practice, the remote site equipment operator will select one of the display operating modes as described in FIG. 15, depending on the number of subjects (camera views) and the capabilities of the remote site computer equipment. Optionally, an additional camera 316 fitted with a wide-angle lens will provide an overall view of the conference room, in accordance with more traditional systems.

To facilitate the aiming of the individual cameras for the participants, an arrangement such as that implemented at airport gates to assist the parking of airplanes (typically an “I” and an “O” formed of neon light tubes is utilized for airplane gate parking) optionally may be included. In this case, the two indicators are mounted so as to overlap only when viewed directly along the optical axis of the camera lens system. Thus, the camera position need only be adjusted so as to cause the indicators to overlap, thereby assuring that the camera correctly is aimed at the subject. A number of microphones 318 are situated around the conference table in locations suitable for proper audio coverage of the participants' speech.

FIG. 13B shows a side-view depicting the physical layout of each of the four sides of the multiple-camera, multiple-display unit 310. The top unit 320 houses the individual cameras (2 to 8 units) and associated electronics, optionally including aiming provisions as described herein above. An LCD display screen 322 shows the various camera images of the conference participants. Speakers located at positions 324 provide audio from the remote sites.

As shown in FIG. 14, the multiple-camera/display unit shown in FIG. 13B preferably is modular in construction including removable side panels, in order to facilitate expansion along either horizontal axis so as to accommodate any size or shape conference table, with each section of the unit serving up to four conference participants. In the preferred embodiment, the entire unit preferably is constructed so as to provide a low profile, by utilizing slanted LCD display panels 330 to create a minimum obstruction for the local conference participants. If a low profile design is not required, the display panels optionally could be larger, and mounted vertically. Until color LCD panels become more cost-effective, the display unit would be constructed with any of the currently available small LCD projector systems. Each conference location may include a designated PC operator, however, the implementation of the network connection facilitates control of the system from a remote location.

It should be noted that the implementation of the PC-based monitoring system is not limited to these examples of security systems or videoconferencing. Many alternative implementations, such as workplace, factory, production line, and process monitoring, would benefit from this system, and these alternative implementations should be considered to be within the scope of the invention.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2995620Jun 27, 1955Aug 8, 1961Hazeltine Research IncColor television-signal convepsion apparatus
US3617626 *May 16, 1969Nov 2, 1971TechnicolorHigh-definition color picture editing and recording system
US3811008Jan 24, 1972May 14, 1974Lee SVideo multiplex system
US3935380Dec 6, 1974Jan 27, 1976Coutta John MSurveillance system
US4051524May 7, 1976Sep 27, 1977Qsi Systems, Inc.Sequential video switching system
US4074225May 9, 1975Feb 14, 1978Engleway CorporationEmergency detection alarm and evacuation system
US4120004Apr 11, 1977Oct 10, 1978Coutta John MSurveillance system
US4138694Feb 23, 1977Feb 6, 1979Sony CorporationVideo signal recorder/reproducer for recording and reproducing pulse signals
US4198656Oct 24, 1975Apr 15, 1980Pelco SalesVideo sequencer-processor
US4237483Mar 19, 1979Dec 2, 1980Electronic Management Support, Inc.Surveillance system
US4324401Jan 15, 1979Apr 13, 1982Atari, Inc.Method and system for generating moving objects on a video display screen
US4360827Jun 2, 1981Nov 23, 1982Darome, Inc.Method and means for interactive audio and video conferencing
US4458266Oct 21, 1981Jul 3, 1984The Commonwealth Of AustraliaVideo movement detector
US4507683Apr 2, 1982Mar 26, 1985Ampex CorporationCamera status and diagnostics display system
US4510526Apr 19, 1983Apr 9, 1985Coutta John MSurveillance system
US4511886Oct 6, 1983Apr 16, 1985Micron International, Ltd.Electronic security and surveillance system
US4516156Mar 15, 1982May 7, 1985Satellite Business SystemsTeleconferencing method and system
US4616319Aug 6, 1984Oct 7, 1986General Electric CompanyStorage of digitized video images on disk
US4618894Apr 6, 1984Oct 21, 1986Victor Company Of Japan, Ltd.Color video signal recording and reproducing apparatus
US4630110Feb 15, 1984Dec 16, 1986Supervision Control Systems, Inc.Surveillance system
US4650929 *Feb 28, 1985Mar 17, 1987Heinrich-Hertz-Institut Fur Nachrichtentechnik Berlin GmbhCommunication system for videoconferencing
US4654703Nov 22, 1985Mar 31, 1987Viera William EVideo camera surveillance system
US4661863Apr 3, 1984Apr 28, 1987Victor Company Of Japan, Ltd.Color video signal recording and reproducing apparatus
US4663518Oct 31, 1985May 5, 1987Polaroid CorporationOptical storage identification card and read/write system
US4673974Jan 7, 1986Jun 16, 1987Hitachi, Ltd.Image transmission system
US4685003Dec 2, 1983Aug 4, 1987Lex Computing & Management CorporationVideo composition method and apparatus for providing simultaneous inputting and sorting of video source material
US4686698Apr 8, 1985Aug 11, 1987Datapoint CorporationWorkstation for interfacing with a video conferencing network
US4691248May 21, 1986Sep 1, 1987Victor Company Of JapanSynchronized signal separating circuit for a recording and reproducing apparatus
US4692806Apr 8, 1986Sep 8, 1987Rca CorporationImage-data reduction technique
US4710917Apr 8, 1985Dec 1, 1987Datapoint CorporationVideo conferencing network
US4712103Dec 3, 1985Dec 8, 1987Motohiro GotandaDoor lock control system
US4729044Feb 5, 1985Mar 1, 1988Lex Computing & Management CorporationMethod and apparatus for playing serially stored segments in an arbitrary sequence
US4739401Jan 25, 1985Apr 19, 1988Hughes Aircraft CompanyTarget acquisition system and method
US4768090Sep 8, 1987Aug 30, 1988Compagnie Generale D'automatisme Cga-HbsSurveillance device using video camera
US4772945May 11, 1987Sep 20, 1988Sony CorporationSurveillance system
US4777526Jun 5, 1987Oct 11, 1988Sony CorporationSecurity monitor system
US4777527Dec 23, 1986Oct 11, 1988Compagnie Generale D'automatisme Cga-HbsMoving video surveillance system
US4811408Nov 13, 1987Mar 7, 1989Light Signatures, Inc.Image dissecting document verification system
US4812924Mar 9, 1987Mar 14, 1989Sony CorporationMethod and apparatus for reproducing or recording a PCM signal and sub data concerning the PCM signal in a paired format
US4814869Apr 27, 1987Mar 21, 1989Oliver Jr Robert CVideo surveillance system
US4823207Jan 30, 1987Apr 18, 1989Hitachi, Ltd.PCM recording and playback with variable read and write speeds
US4829389Nov 16, 1987May 9, 1989Sony CorporationSurveillance video tape recorder
US4847829Nov 25, 1987Jul 11, 1989Datapoint CorporationVideo conferencing network
US4849486Jul 9, 1986Jul 18, 1989Nippon Oil Co., Ltd.Polyphenylene ether resin composition
US4873573Dec 23, 1986Oct 10, 1989British Broadcasting CorporationVideo signal processing for bandwidth reduction
US4876597Aug 18, 1988Oct 24, 1989Adt Security Systems, Inc.Video observation systems
US4879747Mar 21, 1988Nov 7, 1989Leighton Frank TMethod and system for personal identification
US4884898Feb 6, 1989Dec 5, 1989Lee Controls, Inc.Linear motion pillow block including fine tuning features
US4905262Jul 28, 1988Feb 27, 1990Tektronix, Inc.Synchronous programmable two-stage serial/parallel counter
US4931868May 31, 1988Jun 5, 1990Grumman Aerospace CorporationMethod and apparatus for detecting innovations in a scene
US4937685Dec 2, 1983Jun 26, 1990Lex Computer And Management CorporationMethod of display presentation for video editing
US4942464Mar 9, 1989Jul 17, 1990Erhard MilatzSurveillance device for the protection of an automatic delivery apparatus
US4943854Nov 17, 1988Jul 24, 1990Chuo Electronics Co., Ltd.Video surveillance system for selectively selecting processing and displaying the outputs of a plurality of TV cameras
US4951140Feb 22, 1989Aug 21, 1990Kabushiki Kaisha ToshibaImage encoding apparatus
US4961211Jun 30, 1988Oct 2, 1990Nec CorporationTelevision conference system including many television monitors and method for controlling the same
US4962473Dec 9, 1988Oct 9, 1990Itt CorporationEmergency action systems including console and security monitoring apparatus
US4965819Sep 22, 1988Oct 23, 1990Docu-Vision, Inc.Video conferencing system for courtroom and other applications
US4992866Jun 29, 1989Feb 12, 1991Morgan Jack BCamera selection and positioning system and method
US5001348Aug 23, 1989Mar 19, 1991Messerschmitt-Boelkow-Blohm GmbhMethod and apparatus for recognizing the start and motion of objects
US5012334Jan 29, 1990Apr 30, 1991Dubner Computer Systems, Inc.Video image bank for storing and retrieving video image sequences
US5014267Apr 6, 1989May 7, 1991Datapoint CorporationVideo conferencing network
US5027222 *Jun 19, 1989Jun 25, 1991Matsushita Electric Industrial Co., Ltd.Apparatus for recording audio signals and video signals on a recording medium
US5027413Jun 13, 1989Jun 25, 1991U.S. Philips Corp.Target detection systems
US5034986Feb 12, 1990Jul 23, 1991Siemens AktiengesellschaftMethod for detecting and tracking moving objects in a digital image sequence having a stationary background
US5040067Jan 30, 1989Aug 13, 1991Pioneer Electronic CorporationMethod and device for processing multiple video signals
US5095196 *Dec 28, 1989Mar 10, 1992Oki Electric Industry Co., Ltd.Security system with imaging function
US5097328Oct 16, 1990Mar 17, 1992Boyette Robert BApparatus and a method for sensing events from a remote location
US5103306Mar 28, 1990Apr 7, 1992Transitions Research CorporationDigital image compression employing a resolution gradient
US5111290Dec 28, 1990May 5, 1992Gutierrez Frederic JSurveillance system having a miniature television camera and a RF video transmitter mounted in a mannequin
US5117285Jan 15, 1991May 26, 1992Bell Communications ResearchEye contact apparatus for video conferencing
US5128776Jun 16, 1989Jul 7, 1992Harris CorporationPrioritized image transmission system and method
US5142367Dec 14, 1990Aug 25, 1992Goldstar Co., Ltd.System for divisionally displaying plural images on a screen
US5144661Feb 11, 1991Sep 1, 1992Robert ShamoshSecurity protection system and method
US5150212Dec 31, 1990Sep 22, 1992Samsung Electronics Co., Ltd.Control system for recording and reproducing a plurality of video signals
US5179449Jan 11, 1990Jan 12, 1993Kabushiki Kaisha ToshibaScene boundary detecting apparatus
US5182776Mar 4, 1991Jan 26, 1993Hitachi, Ltd.Image processing apparatus having apparatus for correcting the image processing
US5191645Feb 28, 1991Mar 2, 1993Sony Corporation Of AmericaDigital signal processing system employing icon displays
US5202759Jan 24, 1992Apr 13, 1993Northern Telecom LimitedSurveillance system
US5206929Oct 26, 1990Apr 27, 1993Sony Corporation Of AmericaOffline editing system
US5216502Dec 18, 1990Jun 1, 1993Barry KatzSurveillance systems for automatically recording transactions
US5218672Jan 19, 1990Jun 8, 1993Sony Corporation Of AmericaOffline editing system with user interface for controlling edit list generation
US5229850 *Jul 29, 1991Jul 20, 1993Kabushiki Kaisha ToshibaVideo monitoring system including a memory for storing and transmitting a video signal immediately following the occurrence of an event
US5235420Mar 22, 1991Aug 10, 1993Bell Communications Research, Inc.Multilayer universal video coder
US5237408Aug 2, 1991Aug 17, 1993Presearch IncorporatedRetrofitting digital video surveillance system
US5237648Jun 8, 1990Aug 17, 1993Apple Computer, Inc.Apparatus and method for editing a video recording by selecting and displaying video clips
US5243418Nov 27, 1991Sep 7, 1993Kabushiki Kaisha ToshibaDisplay monitoring system for detecting and tracking an intruder in a monitor area
US5253062Sep 19, 1991Oct 12, 1993Fuji Photo Film Co., Ltd.Image displaying apparatus for reading and writing graphic data at substantially the same time
US5258837Oct 19, 1992Nov 2, 1993Zandar Research LimitedMultiple security video display
US5260783Feb 21, 1991Nov 9, 1993Gte Laboratories IncorporatedLayered DCT video coder for packet switched ATM networks
US5270811Jun 21, 1991Dec 14, 1993Fujitsu LimitedTelemetry monitoring method and device therefor for transmitting information by means of asynchronous transfer mode technique in broadband ISDN
US5272527 *Apr 2, 1992Dec 21, 1993Pioneer Electronic CorporationPicture image monitoring system
US5285273Feb 19, 1988Feb 8, 1994British Aerospace Public Limited CompanyTracking system
US5293313Nov 21, 1990Mar 8, 1994Picker International, Inc.Real time physician view box
US5325194Aug 26, 1992Jun 28, 1994Fujitsu LimitedMultipoint video conferencing system
US5335013 *Jan 16, 1992Aug 2, 1994Faber Robert AMethod and apparatus for video camera image film simulation
US5339104Dec 9, 1992Aug 16, 1994Goldstar Co., Ltd.Motion detecting apparatus
US5339393Apr 15, 1993Aug 16, 1994Sony Electronics, Inc.Graphical user interface for displaying available source material for editing
US5341439Aug 21, 1992Aug 23, 1994Hsu Shin YiSystem for texture-based automatic detection of man-made objects in representations of sensed natural environmental scenes
US5382972Sep 8, 1992Jan 17, 1995Kannes; DenoVideo conferencing system for courtroom and other applications
US5400069Jun 16, 1993Mar 21, 1995Bell Communications Research, Inc.Eye contact video-conferencing system and screen
US5422989 *Nov 23, 1992Jun 6, 1995Harris CorporationUser interface mechanism for interactively manipulating displayed registered images obtained from multiple sensors having diverse image collection geometries
US5481297 *Feb 25, 1994Jan 2, 1996At&T Corp.Multipoint digital video communication system
US5491511 *Feb 4, 1994Feb 13, 1996Odle; James A.Multimedia capture and audit system for a video surveillance network
US5502576 *Aug 24, 1992Mar 26, 1996Ramsay International CorporationMethod and apparatus for the transmission, storage, and retrieval of documents in an electronic domain
US5521634 *Jun 17, 1994May 28, 1996Harris CorporationAutomatic detection and prioritized image transmission system and method
US5526133 *Jun 28, 1994Jun 11, 1996Sensormatic Electronics CorporationSystem and method for logging and retrieving information on video cassettes in a computer controlled surveillance system
US5619995 *Jun 14, 1994Apr 15, 1997Lobodzinski; Suave M.For communication with a diagnostic imaging system
US5926611 *Dec 20, 1996Jul 20, 1999Hughes Electronics CorporationHigh resolution digital recorder and method using lossy and lossless compression technique
USD311924Mar 21, 1988Nov 6, 1990Jack Hunter InvestmentsHousing for a simulated video surveillance camera
USD312649Feb 2, 1988Dec 4, 1990Canon Kabushiki KaishaVideo surveillance camera
USD322084Jun 7, 1989Dec 3, 1991Kabushiki Kaisha ToshibaVideo surveillance camera body
USD347839Dec 12, 1990Jun 14, 1994Carota Communications Inc.Video conferencing cabinet
USD349913Jan 22, 1993Aug 23, 1994 Surveillance video camera security box
USD354973Apr 5, 1993Jan 31, 1995Sony CorporationSurveillance video camera
Non-Patent Citations
Reference
1Barthel, Digital Storage Weighed for ATM Surveillance, American Banker, Feb. 22, 1994.
2Carvahlo et al., Automated Detection of Intruders Using a Neural Network, S.P.I.E., Apr. 21, 1992.
3Chang et al., A Remote Multi-Camera Visual Surveillance System Using Frame-Switching Technology, I.E.E.E., Oct. 5-7, 1988.
4Cudworth, Modern Video Surveillance and Control Systems Using Digital Image Processing Methods, I.E.E.E., Mar. 31, 1992-Apr. 2, 1992.
5Darg, a New High-Speed Video System for Motion Analysis, I.E.E.E., Jun. 26-28, 1991.
6Hasegawa et al., Development and Picture Quality Evaluation of a Prototype Hi-Vision Coding System for Facility Monitoring, S.P.I.E., Sep. 16, 1994.
7Hayter et al., The Desk Area Network, ACM SIGOPS Operating Systems Review, Oct. 1991.
8Intellution's Plant TV Brochure Date unknown.
9McLeod, Automated Video Surveillance-Teaching an Old Dog New Tricks, S.P.I.E., Dec. 17, 1993.
10McLeod, Automated Video Surveillance—Teaching an Old Dog New Tricks, S.P.I.E., Dec. 17, 1993.
11Murtoviita et al., Visual Aids for Substation Monitoring and Security Control, I.E.E.E., Jun. 26-28, 1991.
12Newton, Picturing the Future of CCTV, Security Management, Nov. 1, 1994.
13Pappageorge, The Secrets of CCTV, Security Management, Aug. 1, 1993.
14Point-of-sale monitoring downsizes for small venues, May 1993.
15Rangan et al., Designing An On-Demand Multimedia Service, Jul. 1, 1992.
16Rangan et al., Efficient Storage Techniques for Digital Continuous Multimedia, I.E.E.E., Aug. 1, 1993.
17Vicon Industries, Vicon Introduces The V5000DVM Digital Video Multiplexer, Vicon Industries, Apr. 15, 1992.
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US20100061707 *Oct 12, 2007Mar 11, 2010Ryota KosakaiImage capturing apparatus and image capturing method
Legal Events
DateCodeEventDescription
Apr 23, 2013CCCertificate of correction
Aug 8, 2012ASAssignment
Owner name: HAWK TECHNOLOGY SYSTEMS, LLC, MICHIGAN
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:MULTI-FORMAT, INC.;REEL/FRAME:028747/0907
Effective date: 20120807