Multiplexing technique for stereoscopic video system

• US 5,193,000 A
• Filed: 08/28/1991
• Issued: 03/09/1993
• Est. Priority Date: 08/28/1991
• Status: Expired due to Term

• Current Assignee: RealD Incorporated
• Original Assignee: Stereographics Corporation (RealD Incorporated)
• Inventors: Lipton, Lenny, Meyer, Lawrence D., Kramer, Frank K. III
• Primary Examiner(s): Britton, Howard W.
• Application Number:
  US07/751,883
• Time in Patent Office: 559 Days
• Field of Search: 358/92, 358/146, 358/3
• US Class Current: 348/43
• CPC Class Codes: H04N 13/161 Encoding, multiplexing or demultiplexing different image signal components for multi-view video sequence encoding H04N19/597
• 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 13/296 Synchronisation thereof; Control thereof
• CPC Class Codes: H04N 13/337 using polarisation multiplexing
• CPC Class Codes: H04N 13/341 using temporal multiplexing
• CPC Class Codes: H04N 13/363 using image projection screens volumetric display H04N13/388
• CPC Class Codes: H04N 13/398 Synchronisation thereof; Control thereof
• CPC Class Codes: H04N 19/597 specially adapted for multi-view video sequence encoding

Abstract

A method and apparatus for time multiplexing and demultiplexing two channels of picture information within a standard video channel. The method is specifically designed for field sequential stereoscopic display applications, but may be used for non-stereoscopic applications where conservation of bandwidth is required. The technique is superior to prior art commercially available stereoplexing approaches, and increases vertical resolution while decreasing stair-stepping of diagonal lines. The demultiplexing display controller of the invention can be manufactured at a low cost because its design takes advantage of commercially available integrated circuits.

Claims

1. A method for time multiplexing a first video signal comprising horizontal lines and a second video signal comprising horizontal lines, including the steps of:

horizontally compressing the horizontal lines of the fist video signal to generate first compressed line signals;

horizontally compressing the horizontal lines of the second video signal to generate second compressed line signals; and

generating a multiplexed video signal comprising multiplexed line signals, wherein each of the multiplexed line signals consist of a first number of sample of one of the first compressed line signals concatenated with said first number of samples of one of the second compressed line signals.

2. The method of claim 1, wherein the multiplexed video signal has a conventional video bandwidth.

3. The method of claim 1, wherein the multiplexed video signal represents a stereoscopic image, the first video signal represents a first perspective viewpoint of the stereoscopic image, and the second video signal represents a second perspective viewpoint of the stereoscopic image.

4. The method of claim 1, also including the step of:

displaying the multiplexed video signal on a monitor, to produce side-by-side first and second subfield images.

5. The method of claim 1, wherein the multiplexed video signal represents a nonstereoscopic image, the first video signal represents a first planar image, and the second video signal represents a second planar image.

6. The method of claim 1, wherein the multiplexed video signal and the multiplexed line signals include no horizontal sync blanking area and no horizontal sync pulse.

7. A method for time multiplexing a first video signal comprising horizontal lines and a second video signal comprising horizontal lines, including the steps of:

horizontally compressing the horizontal lines of the first video signal to generate first compressed line signals;

horizontally compressing the horizontal lines of the second video signal to generate second compressed line signals;

generating a multiplexed video signal comprising multiplexed line signals, wherein each of the multiplexed line signals consists of one of the first compressed lien signals concatenated with one of the second compressed line signals; and

generating a field-sequential video signal from the multiplexed video signal by expanding and demultiplexing the multiplexed line signals.

8. The method of claim 7, wherein the field-sequential video signal includes a first data stream comprising an expanded version of each of the first compressed line signals, followed by a second data stream comprising an expanded version of each of the second compressed line signals.

9. The method of claim 7, also including the step of:

displaying the field-sequential video signal on a monitor, to produce a field-sequential stereoscopic video image.

10. The method of claim 7, wherein each of the first video signal and the second video signal represents a frame.

11. The method of claim 10, wherein the field-sequential video signal includes a first data stream representing a first odd field, followed by a second data stream representing a second odd field, followed by a third data stream representing a first even field, followed by a fourth data stream representing a second even field.

12. A method for time multiplexing a first video signal comprising horizontal liens and a second video signal comprising horizontal lines, including the steps of:

horizontally compressing the horizontal lines of the first video signal to generate first compressed line signals;

horizontally compressing the horizontal lines of the second video signal to generate second compressed line signals;

generating a multiplexed video signal comprising multiplexed line signals, wherein each of the multiplexed line signals consists of one of the first compressed lien signals concatenated with one of the second compressed line signals;

storing the multiplexed video signal;

generating reproduced multiplexed line signals by plying back the stored multiplexed video signal; and

expanding and demultiplexing the reproduced multiplexed line signals to generate a field-sequential video signal.

13. The method of claim 12, wherein the step of expanding the reproduced multiplexed line signals includes the steps of:

generating first horizontally expanded signals corresponding to the first compressed line signals; and

generating second horizontally expanded signals corresponding to the second compressed line signals, wherein the field-sequential video signal includes a first data stream comprising the first horizontally expanded signals, followed by a second data stream comprising the second horizontally expanded signals.

14. The method of claim 12, wherein each of the first video signal and the second video signal represents a frame, and wherein the field-sequential video signal includes a first data stream representing a first odd field, followed by a second data stream representing a second odd field, followed by a third data stream representing a first even field, followed by a fourth data stream representing a second even field.

15. An apparatus for time multiplexing a first video signal comprising horizontal lines and a second video signal comprising horizontal lines, including:

a means for horizontally compressing the horizontal lines of the first video signal to generate first compressed line signals and for horizontally compressing the horizontal liens of the second video signal to generate second compressed line signals; and

a multiplexing means for generating a multiplexed video signal comprising multiplexed line signals, wherein each of the multiplexed line signals consists of a first number of samples of one of the first compressed lien signals concatenated with said first number of sample of one of the second compressed line signals.

16. The apparatus of claim 15, also including:

a recording and playback means, for recording the multiplexed video signal, and generating reproduced multiplexed line signals by playing back the recorded multiplexed video signal; and

a demultiplexing means, connected to the recording and playback means, and including a means for expanding and demultiplexing the reproduced multiplexed lien signals to generate a field-sequential video signal.

17. The apparatus of claim 16, wherein the reproduced multiplexed line signals have a conventional video bandwidth, and also including:

a transmission link for transmitting data having said conventional video bandwidth, said transmission link connected between an output of the recording and playback means and an input of the demultiplexing means.

18. The apparatus of claim 15, wherein the multiplexed video signal has a conventional video bandwidth.

19. The apparatus of claim 18, also including:

a demultiplexing means which includes means for converting the multiplexed video signal into a field-sequential video signal by expanding and demultiplexing the multiplexed line signals; and

a transmission link for transmitting data having said conventional video bandwidth, wherein the transmission link is connected between an output of the multiplexing means and an input of the demultiplexing means.

20. The apparatus of claim 19, wherein the field-sequential video signal is a stereoscopic video signal including a first data stream representing a first odd field, followed by a second data stream representing a second odd field, followed by a third data stream representing a first even field, followed by a fourth data stream representing a second even field.

21. The apparatus of claim 19, wherein the demultiplexing means includes means for generating first horizontally expanded signals corresponding to the first compressed line signals, and for generating second horizontally expanded signals corresponding to the second compressed line signals, and wherein the field-sequential video signal includes a first data stream comprising the first horizontally expanded signals, followed by a second data stream comprising the second horizontally expanded signals.

22. An apparatus for processing time multiplexed line signals for display, wherein each of the multiplexed line signals consists of a first compressed line signal concatenated with a second compressed line signal, wherein the first compressed line signals represent a first video signal, and wherein the second compressed line signals represent a second video signal, including:

a means for demultiplexing the multiplexed line signals to separate the first compressed line signals from the second compressed line signals; and

a means for generating horizontally expanded first compressed line signals and horizontally expanded second compressed line signals from the separated first compressed line signals and the separated second compressed line signals, and for combining the horizontally expanded first compressed line signals and the horizontally expanded second compressed line signals to generate a field-sequential video signal.

23. The apparatus of claim 22, wherein the field-sequential video signal includes a first data stream comprising the horizontally expanded first compressed line signals, followed by a second data stream comprising the horizontally expanded second compressed line signals.

24. The apparatus of claim 22, wherein each of the first video signal and the second video signal represents a frame, and wherein the field-sequential video signal includes a first data stream representing a first odd field, followed by a second data stream representing a second odd field, followed by a third data stream representing a first even field, followed by a fourth data stream representing a second even field.

25. An apparatus for processing time multiplexed line signals for display, wherein each of the multiplexed line signals consists of a first compressed data stream concatenated with a second compressed data stream, wherein the first compressed data streams represent a first video signal, and wherein the second compressed data streams represent a second video signal, including:

a memory means having storage locations which map into a grid of rows and columns;

a write means for writing the first compressed data streams into a first set of row locations of the memory means at a first data rate, and for writing the second compressed data streams into a second set of row locations of the memory means at said first data rate; and

a read means for reading the data stored in the first set of row locations at a second data rate lower than said first data rate, and thereafter reading the data stored in the second set of row locations at the second data rate, to generate a field-sequential video signal.

26. The apparatus of claim 25, wherein the storage locations map into a grid of rows and columns defining a 512×

512 pixel array, wherein each of the first and the second compressed data streams comprises three sections of 128 pixels.

27. The apparatus of claim 25, wherein each of the first video signal and the second video signal represents a frame, and wherein the field-sequential video signal includes a first data stream representing a first odd field, followed by a second data stream representing a second odd field.

28. The apparatus of claim 27, wherein the field-sequential video signal includes a first data stream representing a first odd field, followed by a second data stream representing a second odd field, followed by a third data stream representing a first even field, followed by a fourth data stream representing a second even field.

29. An apparatus for processing time multiplexed lien signals for display, wherein each of the multiplexed lien signals consist of a first number of samples of a first compressed data stream concatenated with said first number of sample of a second compressed data stream, wherein the first compressed data streams represent a first video signal, and wherein the second compressed data streams represent a second video signal, including:

a demultiplexing means for receiving the time multiplexed line signals and processing the time multiplexed line signals to produce parallel first and second channels of video information;

first projection means for receiving the first channel of video information and projecting a first video image representing said firs channel; and

second projection means for receiving the second channel of video information and projecting a second video image representing said second channel.

30. The apparatus of claim 29, also including:

a first polarizing filter for imposing a first polarization characteristic on the projected first video image; and

a second polarizing filter for imposing a second polarization characteristic on the projected second video image.

31. A method for time multiplexing a first video signal comprising horizontal lines and a second video signal comprising horizontal lines, including the steps of:

discarding selected pixels comprising each of the horizontal lines of the first video signal to generate first partial lien signals;

discarding selected pixels comprising each of the horizontal lines of the second video signal to generate second partial line signals; and

generating a multiplexed video signal having a bandwidth substantially identical to that of the first video signal, wherein the multiplexed video signal comprises multiplexed line signals, and wherein each of the multiplexed line signals consists of a first number of sample of one of the first partial line signals concatenated with said first number of samples of one of the second partial line signals.

32. An apparatus for processing time multiplexed line signals for display, wherein each of the time multiplexed line signals consists of a first compressed data stream concatenated with a second compressed data stream, wherein the first compressed data streams represent a first video signal, and wherein the second compressed data streams represent a second video signal, including:

a first-in-first-out memory means for receiving the time multiplexed line signals; and

a read means for reading a field-sequential video signal from the memory means.

33. The apparatus of claim 32, also including:

a color space conversion means for receiving the field-sequential video signal, and generating a field-sequential RGB video signal from the field-sequential video signal.