Three dimensional television system

• US 4,567,513 A
• Filed: 11/02/1983
• Issued: 01/28/1986
• Est. Priority Date: 11/02/1983
• Status: Expired due to Term

• Current Assignee: Donald J. Imsand
• Original Assignee: Donald J. Imsand
• Inventors: Imsand, Donald J.
• Primary Examiner(s): Britton, Howard W.
• Assistant Examiner(s): Kostak, Victor R.
• Application Number:
  US06/547,897
• Time in Patent Office: 818 Days
• Field of Search: 358/88, 358/89, 358/91, 358/92, 358/3
• US Class Current: 348/55
• CPC Class Codes: H04N 13/00 Stereoscopic video systems; Multi-view video systems; Details thereof
• CPC Class Codes: H04N 13/10 Processing, recording or transmission of stereoscopic or multi-view image signals
• CPC Class Codes: H04N 13/189 Recording image signals; Reproducing recorded image signals
• CPC Class Codes: H04N 13/239 using two 2D image sensors having a relative position equal to or related to the interocular distance H04N13/243 takes precedence
• CPC Class Codes: H04N 13/30 Image reproducers optical systems for producing stereoscopic or other three-dimensional effects G02B30/00
• CPC Class Codes: H04N 2013/0081 Depth or disparity estimation from stereoscopic image signals

Abstract

Methods and apparatus for producing a television image having the illusion of three dimensional depth. This method is compatible with television broadcast standards and standard home TV receivers without additional home apparatus. The basic methodology is to alternate video from two stereoscopic TV cameras, using a synchronized video switch, at an alternation rate to allow the human visual perception process to perceive the two images as a single binocularly fused image. However, this basic method has an inherent flicker problem related to the "limit of binocular fusion" of the human visual perception process. The flicker problem is eliminated through video processing techniques that produce globally converged alternating binocular video. The method is also compatible with display mediums other than television.

Claims

1. A method of displaying a stereo pair of images to present a single, three dimensional, sharply focused, flicker-free image to human visual perception comprising the steps of:

(a) positioning a pair of video cameras in stereo relation to each other to view a scene,

(b) displaying the video signal from first one camera,

(c) displaying the video signal from the second camera in registration with the display of the first signal, in binocular relationship to the first signal and for approximately the same period as the first signal,

(d) switching between display of the first and second signals at a rate between 3 and 25 of each image per second, and

(e) monitoring the light level of the scene and increasing the rate of switching between display of the first and second signals responsive to higher light levels.

2. A television system for displaying a three dimensional, sharply focused, flicker-free image to human visual perception, comprising:

(a) a pair of video cameras positioned in stereo relation to each other to view a scene,

(b) means for transmitting the video signal from first one of the pair of cameras and then the other camera for approximately equal periods and switching between the video signals from the first and second camera at a rate between 3 and 25 of each image per second, and

(c) means for receiving the transmitted video signals and displaying such signals in registration and in binocular relationship to each other, said binocular relation displaying means comprising;

(i) means for measuring the characteristics of each of the two video signals,

(ii) means for comparing the characteristics and time occurrence of video elements within each of the two video signals,

(iii) means for identifying corresponding video elements within each of the two video signals not within the limits of human binocular fusion, and

(iv) means for processing the video signal from the one camera to time shift the video elements not within the limits of binocular fusion to bring such elements within the limits of binocular fusion when the processed video signal is displayed together with the video signal from the other camera.

3. A method for producing a pair of stereo scopic images, the corresponding objects of which are within a viewer'"'"'s limit of binocular fusion comprising the steps of:

(a) repositioning the corresponding objects in the two images to corresponding positions such that when the two images are superimposed the video objects at all ranges coincide; and

(b) filling in voids created in each image by such repositioning of the objects by using corresponding image elements from the other image.

4. A method of displaying a stereo pair of images to present a single, three dimensional, sharply focused, flicker-free image to human visual perception comprising the steps of:

(a) separately producing stereo video images of only foreground objects located approximately equal distances from a first pair of cameras against a solid color background,

(b) separately producing stereo video images of only midground objects located approximately equal distances from a second pair of cameras against a solid color background,

(c) separately producing monocular video of only background objects,

(d) combining the foreground, midground and background video images such that the solid color background of the midground video is replaced by corresponding portions of the monocular background objects video and the solid color background of the foreground video is replaced by corresponding portions of the combined midground and background video,

(e) displaying first the combined video signal from the background video and one camera of each of the pairs of foreground and midground cameras,

(f) displaying the combined video signal from the background video and the other cameras of the pairs of foreground and midground cameras in registration with the display of the first signal, in binocular relationship to the first signal and for approximately the same period as the first signal, and

(g) switching between display of the first and second signals at a rate between 3 and 25 of each image per second.

5. The method in accordance with claim 4 further comprising the step of displaying the second signal for a substantially shorter period than display of the first signal.

27. The method of claim 4 wherein said video signal processing step includes time delay shifting, by different delay periods, of at least two video elements within one of the video signals.

28. The method in accordance with claim 27 further comprising the step of positioning the video cameras one above the other.

29. The method in accordance with claim 27 further comprising the step of using video cameras which are vertical scan video cameras.

30. The method in accordance with claim 27 further comprising the step of displaying the second signal for a substantially shorter period than display of the first signal.

6. A method of displaying a stereo pair of images to present a single, three dimensional, sharply focused, flicker-free image to human visual perception comprising the steps of:

(a) positioning a pair of vertical scan video cameras in stereo relation to each other to view a scene,

(b) displaying the video signal from first one camera,

(c) displaying the video signal from the second camera in registration with the display of the first signal, in binocular relationship to the first signal and for approximately the same period as the first signal, and

(d) switching between display of the first and second signals at a rate between 3 and 25 of each image per second.

7. The method in accordance with claim 6 further comprising the step of displaying the second signal for a substantially shorter period than display of the first signal.

8. A method of displaying a stereo pair of images to present a single, three dimensional, sharply focused, flicker-free image to human visual perception comprising the steps of:

(a) positioning a pair of video cameras in stereo relation to each other to view a scene,

(b) processing the signals from the cameras to identify the video elements within the scene which are not within the limit of binocular fusion and elements that are within the limit of binocular fusion,

(c) combining the video signals from the cameras such that video elements which are within the limit of binocular fusion are alternately displayed for approximately equal periods, alternating at a rate between 3 and 25 of each image per second, and

(d) displaying video signals from only one of the cameras continuously for video elements not within the limit of binocular fusion.

9. The method in accordance with claim 8 further comprising the step of positioning the video cameras one above the other.

10. The method in accordance with claim 8 further comprising the step of using video cameras which are vertical scan video cameras.

11. The method in accordance with claim 8 further comprising the step of displaying the second signal for a substantially shorter period than display of the first signal.

12. A method of displaying a stereo pair of images to present a single three dimensional, sharply focused, flicker-free image to human visual perception comprising the steps of:

(a) positioning a plurality of pairs of video cameras to view a scene such that the cameras of each pair are in stereo relation to each other and each pair of cameras is converged at a different distance within the scene,

(b) synthesizing a first composite video signal depicting the scene from one of the cameras in each pair of cameras utilizing convergence detector circuitry, switching circuitry and layered video circuitry,

(c) displaying the first video signal,

(d) synthesizing a second composite video signal depicting the scene from the other camera in each pair of cameras utilizing convergence detector circuitry, switching circuitry and layered video circuitry,

(e) displaying the second video signal in registration with the display of the first signal, in binocular relationship to the first signal and for approximately the same period as the first signal, and

(f) switching between display of the first and second composite video signals at a rate between 3 and 25 of each image per second.

13. The method in accordance with claim 12 further comprising the step of positioning the video cameras within each pair of cameras one above the other.

14. The method in accordance with claim 12 further comprising the step of using video cameras which are vertical scan video cameras.

15. The method in accordance with claim 12 further comprising the step of displaying the second signal within each pair of signals for a substantially shorter period than display of the first signal.

16. A method of displaying a stereo pair of images to present a single, three dimensional, sharply focused, flicker-free image to human visual perception comprising the steps of:

(1) positioning a pair of video cameras in stereo relation to each other to view a scene,

(2) displaying the video signal from first one camera,

(3) displaying the video signal from the second camera;

(i) in binocular relationship to the first signal by;

(a) measuring the characteristics of each of the two video signals,

(b) comparing the characteristics and time occurrence of video elements within each of the two video signals,

(c) identifying corresponding video elements within each of the two video signals not within the limits of human binocular fusion, and

(d) processing the video signal from one camera to time shift the video elements not within the limits of binocular fusion to bring such elements within the limit of binocular fusion when the processed video signal is displayed together with the video signal from the second camera in accordance with said switching step,

(ii) in registration with the display of the first signal and

(iii) for approximately the same period as the first signal, and

(4) switching between display of the first and second signals at a rate between 3 and 25 of each image per second.

17. The method in accordance with claim 16 further comprising the step of positioning the video cameras one above the other.

18. The method in accordance with claim 16 further comprising the step of using video cameras which are vertical scan video cameras.

19. The method in accordance with claim 16 further comprising the step of alternating the two video signals at the field alternation rate such that one signal is displayed in one interlaced field and the other signal is displayed in the other interlaced field.

20. The method in accordance with claim 16 further comprising the step of displaying the second signal for a substantially shorter period than display of the first

21. The method in accordance with claim 16 wherein said comparing step is performed by detecting the edges of video objects and comparing the characteristics of video elements within such objects.

22. The method in accordance with claim 21 further comprising the step of displaying the second signal for a substantially shorter period than display of the first signal.

23. The method in accordance with claim 16 wherein said identifying step is performed by backlighting some objects in the video scene with light invisible to the video camera and detecting object elements so backlit.

24. The method in accordance with claim 23 further comprising the step of displaying the second signal for a substantially shorter period than display of the first signal.

25. The method in accordance with claim 16 wherein said identifying step is performed by range gating utilizing pulsed electromagnetic radiation.

26. The method in accordance with claim 25 further comprising the step of displaying the second signal for a substantially shorter period than display of the first signal.