WO1994030009A1

WO1994030009A1 - Seamless composite photography

Info

Publication number: WO1994030009A1
Application number: PCT/US1994/006761
Authority: WO
Inventors: Robert A. Shelton
Original assignee: Out-Takes, Inc.
Priority date: 1993-06-15
Filing date: 1994-06-15
Publication date: 1994-12-22
Also published as: AU7109094A

Abstract

A system and method for producing a still image that is particularly adapted for integrating with another still image into one composite still image. A combination of a predetermined characterizing background (12) such as a projected blue image or a colored process screen and coordinated flash lighting (23) are utilized together with a still camera (16) or other still imager. The characterizing background is used as a backdrop to a foreground object (13), the characterizing background having predetermined characteristics such as a narrow window in the color spectrum, a predetermined pattern, or both. The foreground object is illuminated by the flash and an image is captured in still form by an imaging medium such as conventional film or a charge-couple imager. Thereafter, the captured image may be combined digitally with one or more digitally recorded images to produce a seamlessly integrated composite image.

Description

SEAMLESS COMPOSITE PHOTOGRAPHY

This invention relates to seamless composite photography and more particularly to such photography using characterizing backdrops such as a process screen background in combination with photographic flash illumination controlled to exhibit predetermined characteristics.

BACKGROUND OF THE INVENTION

In practicing the photographic arts, it has heretofore been proposed to produce seamless composites in which a predetermined subject is incorporated into one or more selected scenes (e.g., in motion pictures) in such a way as to appear to be original photography rather than a contrived combination. Illustrative of such prior proposals are those set forth in United States Patents 4,169,666 granted October 2, 1979 to Slater et al and 4,417,791 granted November 29, 1983 to Erland et al, such patents relating to traveling matte cinematography, i.e., motion pictures or video. It has also been proposed to produce still composite pictures using continuous lighting, illustrative of which is United States Patent 3,149,969 which was granted September 22, 1964 to Petro Vlahos. However, when practicing prior proposals, it has often been necessary for an operator to perform manual touch-ups of the ι composite so as to eliminate tell-tale indications that render the composite unrealistic. Moreover, while a minor mis-match can be tolerated in motion picture composites due in part to the rapidity with which individual frames are projected and the inability of the human eye to discern minor anomalies in such rapidly changing projections, a higher degree of matching must be employed for still-type image capture to produce seamless integration that appears genuine.

As will be observed from references to United States Patent 3,149,969, it has been customary to use continuous illumination for composite still photography. There have been a variety of reasons. These include the simplicity of continuous illumination, its spectral characteristics and its low cost. Moreover, when used with conventional photographic film and previewing equipment such as a video display, continuous illumination has been generally compatible with the color characteristics of the backdrops, the film and the video camera, thus contributing to facility of use.

Although photographic flash illumination such as strobe lighting has been used in studio portraiture and in specialized motion picture applications, it has presented certain problems and disadvantages in the production of still image composite photographs. Thus, for example, strobe illumination is more complex and costly than conventional continuous lighting. Moreover, when including image capture on two or more different photosensitive media, optimum levels of strobe light needed for exposing conventional color film typically have overpowered electronic imaging equipment such as video cameras or have tended to wash out the color characteristics of backdrops. Synchronizing problems have heretofore been encountered in coordinating the timing of differing image-capturing devices such as film cameras, video imaging devices and brief duration illumination sources. Accordingly, the practice of seamless composite still photography has heretofore been accomplished with continuous conventional lighting.

Although the use of continuous conventional lighting and the attendant equipment therefor have the advantages of simplicity, dependability and low cost, they also present some disadvantages. These include excessive heat and the inefficient use of electricity, both in providing the lighting, and also in operation of air conditioning or ventilating equipment required to maintain the ambient room temperatures at a reasonable comfort level. Continuous lighting sources also lack the advantage of being able to freeze action for a live subject such as is necessary in many professional photography or studio portraiture situations.

To ameliorate the foregoing disadvantages of the prior art, provision is herein made to utilize characterizing backdrops, which in the preferred embodiment are process screens having characteristics that are computer distinguishable from foreground objects. These process screens are employed in combination with photographic flash illumination, such as provided by strobe lights, in such a way as to avoid process screen wash-out while being coordinated with any of a predetermined plurality of image capturing components such as still cameras with conventional film, charge-coupled devices, video capture and display. Thus, advantage is taken of the full potential of strobe photography, thereby expanding the utility of composite photography to the professional photographer.

The methods and apparatus according to the invention are specially adaptable to employment of digital processing of both the background and foreground portions of the proposed composite utilizing a variety of integration techniques.

BRIEF SUMMARY OF THE INVENTION

The foregoing is accomplished through the cooperative combination of characterizing backdrop (e.g., process screen) techniques with image capture modes coordinated with controlled flash illumination to produce still image representations that include a characterizing background together with a desired foreground, the latter typically being a person or object a photographer desires to incorporate into a selected image. The still image representations are particularly adaptable each to being scanned and digitized electronically for combination under the control of a computer with a selected background into a composite image that appears genuine and realistic. OBJECTS AND FEATURES OF THE INVENTION

It is one general object of the invention to improve seamless photographic integration.

It is another object of the invention to enhance comfort of subjects whose visual image is being recorded.

It is another object of the invention to increase efficient use of lighting in producing still photographic images. It is still another object of the invention to prevent wash-out of the characteristics of process screens when employing photographic flash illumination.

It is yet one other object of the invention to enhance image quality by preventing the blurring of the capture that otherwise might occur if the subject moves during exposure.

Accordingly, in accordance with one feature of the invention, photographic flash or flash illumination such as strobe lighting is employed in combination with a characterizing background such as a process screen and an image-capturing medium, thereby improving efficiency and comfort.

In accordance with another feature of the invention, and in the preferred embodiment, conventional video capture is employed in combination with a process screen background, flash illumination and still photography imaging, thereby facilitating real-time monitoring, subject posing and frame selection.

In accordance with yet another feature of the invention, through the use of flash illumination, provision is made to over-power adverse lighting characteristics that may otherwise be introduced by ambient lighting, thereby facilitating the photographer to consistently reproduce and control the intensity and characteristics of the image-capturing operative light.

These and other objects and features of the invention will be apparent from the following description, by way of a preferred embodiment, with reference to the drawings. BRIEF DESCRIPTION OF THE DRAWING

Figure 1 is a perspective view illustrating a studio having equipment in accordance with the invention; and

Figures 2a and 2b are flow diagrams depicting the sequence of actions performed by the system.

DESCRIPTION OF A PREFERRED EMBODIMENT It also may be helpful to define the following terms as employed both in this specification and the attendant claims:

Characterizing Background means an intentional backdrop having predetermined characteristics that are identifiable by imaging devices and distinguishable by digital processing equipment from foreground objects. Included within such definition are projected mono¬ chromatic light and Process Screens.

Process Screen or Process Screens means one or more physical backdrops having a uniform surface color of a relatively narrow spectral range, a predetermined pattern adapted for image recognition, luminescence of a predetermined character, polarized transreflectances, or a combination of two or more of the attributes.

Photographic Flash or Flash Illumination means an intense light of brief duration that is intentionally activated in order to provide principal illumination for capturing an image by a photosensitive medium. Included within such definition are Strobe or Strobe Lighting, as defined below.

Strobe or Strobe Lighting means an intense light of extremely brief duration emanating from the gaseous discharge of electrical current through a gas discharge member.

Request for Flash Signal means a mechanical indicia or electrical signal intentionally designated to result in immediate or momentarily delayed activation of a Photographic Flash.

Now turning to the drawing, and more particularly Figure 1 thereof, it will be seen to portray a photographic studio generally shown at 10. Preferably included within this studio are conventional lights (not shown) positioned so as to provide an acceptable level of continuing ambient light. Also included within this studio is Process Screen 11 having a surface 12 that is characterized as set forth in the foregoing definition.

Positioned in front of surface 12 and above surface 14 of a floor or other support 15 is foreground subject 13 whose image is to be captured by an image- capturing device such as camera 16. While not necessary to the practice of the inventions hereof, the camera 16 is preferably made movable in any of the three directions defined by arrows c-c (side-to-side direction) , d-d (vertical direction) and e-e (forward and backward direction) .

Also, while not necessary to the practice of the inventions hereof, to support the strobe lighting assembly (which is hereinafter described) , there is provided a structural support which may take any of a number of known geometrical forms such as the conventional support shown which includes vertical and horizontal support members 17, 17a and 17b. Attached to support members 17 and 17a by any suitable means are optional guide rails 18 and 18a having tracks 19 and 19a in which the lower portions 20 and 20a of a hemispherically shaped support 21 may be moved forward or rearward as shown by arrows f-f. Also provided at points of movable attachment of hemispherical support 21 to guide rails 18 and 18a are pivots 22 and 22a which permit controlled pivoting of support 21 in the directions shown by arrows a-a.

Hemispherical support 21 preferably includes conventional tracks, grooves or the like with which mating conventional movable supports (not shown) for strobe light 23 engage. By virtue of such conventional mating movable supports, strobe light 23 can be moved along a hemispherical arc corresponding to the arc of hemispherical shaped support 21 as denoted by curved arc segment b-b.

While not necessary for the practice of the inventions hereof, provision is also preferably made for bi-axial movement of the position from which light emitted by strobe light 23 is directed. That, together with movement along the hemispherical path defined by hemispherically shaped support 21, provides improved adjustability for the strobe unit 23.

Further reference to Figure 1 reveals the presence of optional additional imaging device 25 which may be a video camera or charge-coupled device still camera. Also depicted are strobe synchronizing module 28, light intensity coordinating module 29, optional computer 30 and optional computer keyboard 31. As mentioned above, strobe synchronizing module 28 is provided to coordinate the timing of the strobe flash with the shutter of a conventional film camera, if used, or with the scanning sequence of charge-coupled devices if employed in practicing the principles hereof.

Also, as mentioned above, when the principles of the invention are employed with imaging devices having different levels of sensitivity, it is desirable to provide for coordination therebetween by momentarily adjusting the sensitivity of one or more of such devices so that they are compatible with each other and with the level of lighting provided by the strobe. Thus, since it known that when a video camera such as camera 25 is utilized with an imaging device such as film camera 16, the level of light employed with conventional color film tends to overpower the video camera and result in a washed out image, the light intensity coordinating module produces an electrical signal to which the otherwise overpowered imaging device is responsive to lower the sensitivity of such imaging device for the duration of the strobe flash, thus coordinating such device and preventing undesired washout. Correspondingly, after the conclusion of the strobe flash, the imager is returned to its previous state which normally is adjusted for levels of ambient lighting that ordinarily are provided within the studio.

Circuits capable of providing the foregoing coordinating signal are known in the art and may take the form of any of a variety thereof.

Now turning to Figures 2a and 2b, there is shown a flow diagram depicting the sequence of actions performed by the system. A necessary step in practicing the invention is to deploy a characterizing background such as a Process Screen in the desired location. This is represented by rectangle 40 "Positioning Process Screen." It is also necessary to deploy or position a still frame imaging device. This is represented by rectangle 41 "Positioning a Still Frame Imaging Device." Although these steps are needed in order to successfully implement the invention hereof, in certain instances they may be performed only once during the construction and operation of a studio. Alternatively, they may be performed more often as, for example, by the brief projection of monochromatic light; or, in the case of a portable process screen, by the movement or repositioning of the still frame imaging device. Accordingly, it is not contemplated that each time an image is captured that the characterizing backdrop (e.g., Process Screen) or camera necessarily be re-positioned.

In the preferred embodiment, when the Process Screen and still frame imaging device are in the desired position, a selected subject is interposed between the imaging device and the Process Screen. This is represented by rectangle 42 "interposing a Selected Subject Between the Imaging Device and the Process Screen." Next, and after any posing of the subject that may be necessary or desirable, and any desired repositioning of the light sources, the operator (not shown) initiates a Request for Flash. This is represented by rectangle 43 "Request for Flash." Such request may be initiated by any of a nu ber of known devices such as by operation of a conventional shutter release, depressing a selected key on a computer keyboard such as keyboard 31 (Figure 1) , or operation of an electrical switch. In response to the Request for Flash, an electrical Request for Flash Signal is generated as by circuits well known in the art. This electrical signal is represented by rectangle 44 "Request for Flash Signal."

For embodiments that employ a video camera in addition to the still frame imaging device, there is provided "And" circuit 46 to which the Request for Flash Signal is communicated via path 45. In single imaging systems, such "And" circuit and the Video Field Signal as represented by rectangle 47 are eliminated or not needed. Moreover, in such single imaging systems, sensitivity coordination as represented by rectangle 48 "Sensitivity Coordination" is not needed and is either eliminated or by-passed. In such event, the aforementioned Request for Flash Signal 44 is communicated directly to the input 50 of the activating circuits of the Strobe Light 23 (Figure 1) as represented by the "Strobe Fires" rectangle 51 of Figure 2b. However, in embodiments utilizing both a video and a still imaging device, the concurrent occurrence of the Request for Flash Signal at path 45 and a video field signal on path 52 results in an activating output being conducted over path 49 to the aforementioned sensitivity coordination circuits represented by rectangle 48 "Sensitivity Coordination", where they initiate an adjustment of the sensitivity of the video imaging device so as to cause it to be compatible with the level of light emitted when the Flash illumination device, e.g.. Strobe Light 23 (Figure 1) fires. In such embodiment, as soon as the sensitivity coordination circuits are activated, an electrical signal is conducted via path 50 to fire Strobe 23. The resulting Flash illumination of the subject and Process Screen is represented by path 53 and rectangle 54 "Illuminates Foreground Object and Process Screen." While the subject and Process Screen are illuminated, one or more images are captured by the still frame imager and, if included, by any other imagers. This is represented by path 55 and rectangle 56 "Image Recorded by Imaging Device(s)."

In considering the foregoing, it will be evident to those skilled in the art that coordination through sensitivity adjustment can be accomplished in many ways including reducing the gain on the camera, attenuating the video signal, or introducing or controlling a neutral density filter. This can also be done manually as by adjusting a lens iris or automatically as, for example under control of a solenoid whose action is coordinated with the Request for Flash Signal.

It will now be evident that there has been described herein an improved method and combination adapted for use in seamless composite photograph. It will also be evident that the method and apparatus described exhibit attractive features as mentioned above and overcome problems of the prior art. It should also be evident that the described System provides enhanced effectiveness while exhibiting improved operating characteristics; and that it is relatively simple in design and easy and cost effective to produce and use, thus contributing to its attractiveness and desirability.

Although the inventions hereof have been described by way of example of preferred embodiments, it will be evident that other adaptations and modifications may be employed without departing from the spirit and scope thereof. For example, other provisions could be made for Flash Illumination coordination, positioning the component devices and capture devices.

The terms and expressions employed herein have been used as terms of description and not of limitation; and thus, there is no intent of excluding equivalents, but on the contrary it is intended to cover any and all equivalents that may be employed without departing from the spirit and scope of the invention.

Claims

What is claimed is:

1. A system for forming images comprising: a characterizing background, a still camera for capturing an image of a subject against said characterizing background, a source of flash illumination, and means including said still camera and said source of flash illumination for coordinating the timing associated with capturing an image of said subject and said characterizing background.

2. A system for forming images comprising: a characterizing background, a still camera for capturing an image of a subject against said characterizing background, a source of flash illumination, and means including said still camera and said source of flash illumination for simultaneously capturing an image of said subject and said characterizing background.

3. A system according to Claim 2 in which said still camera includes a charge-coupled device imaging detector.

4. A system according to Claim 2 in which said still camera includes a charge-coupled device imaging detector.

5. A system according to Claim 2 in which said still camera includes both a charge-coupled device imaging detector for capturing said image of said subject and photographic film for capturing said image of said subject.

6. A system according to Claim 2 further including a video camera for recording a video image of said subject.

7. A system according to Claim 3 further including a video camera for recording a video image of said subject.

8. A system according to Claim 4 further including a video camera for recording a video image of said subject.

9. A system according to Claim 5 further including a video camera for recording a video image of said subject.

10. A system according to Claim 2 wherein said characterizing background is a process screen.

11. A system according to Claim 3 wherein said characterizing background is a process screen.

12. A system according to Claim 4 wherein said characterizing background is a process screen.

13. A system according to Claim 5 wherein said characterizing background is a process screen.

14. A system according to Claim 6 wherein said characterizing background is a process screen.

15. A system according to Claim 7 wherein said characterizing background is a process screen.

16. A system according to Claim 8 wherein said characterizing background is a process screen.

17. A system according to Claim 9 wherein said characterizing background is a process screen.

18. A method of capturing an image of a subject and a characterizing background comprising the steps of:

(1) deploying a characterizing background;

(2) positioning a still frame imaging device before said characterizing background with said still frame imaging device pointing toward said characterizing background;

(3) interposing a selected subject between said still frame imaging device and said characterizing background;

(4) positioning lighting sources with regard to said subject and said characterizing background and adjusting the duration, color temperature and density of light emanating from said lighting sources; and

(5) activating flash illumination and said still frame imaging device to momentarily illuminate said selected subject thereby simultaneously to capturing an image of said subject and at least a part of said characterizing background.

19. A method of capturing an image of a subject and a characterizing background comprising the steps of:

(1) deploying a characterizing background;

(3) interposing a selected subject between said still frame imaging device and said characterizing background; and

(4) activating flash illumination and said still frame imaging device to momentarily illuminate said selected subject, thereby simultaneously to capturing an image of said subject and at least a part of said characterizing background.

20. The method of Claim 19 further including the step of selecting said characterizing background from the group consisting of a process screen, a predetermined pattern, a predetermined uniform color having a relatively narrow spectral range, a predetermined plurality of such colors, and a combination of a pattern and one or more predetermined colors.

21. The method according to Claim 19 further including the step of capturing said image of said subject and said characterizing background onto photographic film.

22. The method according to Claim 19 further including the step of capturing said image of said subject and said characterizing background onto a charge-coupled device imager.

23. The method according to Claim 19 further including the step of capturing an image of said subject and said characterizing background into a video camera.

24. The image produced by any one of the methods of Claims 18-23.