3D cameras for HDR

• US 9,210,322 B2
• Filed: 12/14/2011
• Issued: 12/08/2015
• Est. Priority Date: 12/27/2010
• Status: Expired due to Fees

• Current Assignee: Dolby Laboratories Licensing Corporation (Dolby Laboratories Incorporated)
• Original Assignee: Dolby Laboratories Licensing Corporation (Dolby Laboratories Incorporated)
• Inventors: Ninan, Ajit, Daly, Scott, Ward, Gregory John, Atkins, Robin
• Primary Examiner(s): Perungavoor, Sath V
• Assistant Examiner(s): Hilaire, Clifford
• Application Number:
  US13/326,273
• Publication Number:
  US 20120162366A1
• Time in Patent Office: 1,455 Days
• Field of Search: 348/47, 348/49
• US Class Current: 1/1
• CPC Class Codes: H04N 13/106 Processing image signals for multi-view video sequence encoding H04N19/597
• CPC Class Codes: H04N 13/139 Format conversion, e.g. of frame-rate or size
• 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 13/289 Switching between monoscopic and stereoscopic modes
• CPC Class Codes: H04N 2013/0088 Synthesising a monoscopic image signal from stereoscopic images, e.g. synthesising a panoramic or high resolution monoscopic image
• CPC Class Codes: H04N 23/73 by influencing the exposure time
• CPC Class Codes: H04N 23/741 by increasing the dynamic range of the image compared to the dynamic range of the electronic image sensors
• CPC Class Codes: H04N 23/951 by using two or more images to influence resolution, frame rate or aspect ratio
• CPC Class Codes: H04N 25/58 involving two or more exposures

Abstract

High dynamic range 3D images are generated with relatively narrow dynamic range image sensors. Input frames of different views may be set to different exposure settings. Pixels in the input frames may be normalized to a common range of luminance levels. Disparity between normalized pixels in the input frames may be computed and interpolated. The pixels in the different input frames may be shifted to, or stay in, a common reference frame. The pre-normalized luminance levels of the pixels may be used to create high dynamic range pixels that make up one, two or more output frames of different views. Further, a modulated synopter with electronic mirrors is combined with a stereoscopic camera to capture monoscopic HDR, alternating monoscopic HDR and stereoscopic LDR images, or stereoscopic HDR images.

Claims

1. A method for creating one or more high dynamic range (HDR) images using a stereoscopic camera, the method comprising:

capturing a scene using a stereoscopic camera with a synopter;

generating from the captured scene a first input image and a second input image, wherein the second input image uses a different exposure than the first input image; and

combining said two input images into a single output image.

2. The method of claim 1, wherein generating one of the input images further comprises filtering an optical path between a lens and one of the sensors of the stereoscopic camera.

3. The method of claim 2, wherein the filtering step comprises using a neutral density filter.

4. The method of claim 1, wherein the synopter is located in front of the lenses and the sensors of the stereoscopic camera.

5. The method of claim 1, wherein the synopter is located between the lenses and the sensors of the stereoscopic camera.

6. The method of claim 1, wherein the two input images are generated using a synopter that comprises at least one mirror with unequal reflectance and transmittance ratios.

7. The method of claim 6, wherein the mirror with unequal reflectance and transmittance ratio comprises at least one of a partially silvered mirror or an electronic mirror.

8. The method of claim 7 wherein the ratio of reflectance to transmittance ratios of the mirror is approximately 80%:

20%.

9. A method for creating one or more high dynamic range (HDR) stereoscopic images using a standard dynamic range (SDR) stereoscopic camera, the method comprising:

capturing a stereoscopic SDR image;

capturing a monoscopic HDR image using a stereoscopic camera with a synopter;

generating an image depth map from said captured stereoscopic SDR image;

combining said depth map, said stereoscopic SDR stereoscopic image, and said monoscopic HDR image; and

,

creating an output stereoscopic HDR image based on the combining step.

10. The method of claim 9, further comprising:

motion compensating the captured monoscopic HDR image in relation to the captured SDR stereoscopic image before the combining step is performed.

11. The method of claim 9, further comprising:

motion compensating the captured stereoscopic SDR images in relation to the captured monoscopic input HDR image before the combining step is performed.

12. The method of claim 9, wherein the synopter further comprises two electronic mirrors, wherein the two electronic mirrors switch between a reflective mode and a transmissive mode.

13. The method of claim 12, wherein the two electronic mirrors switch between the reflective mode and the transmissive mode at a rate that is two or more times higher than a desired output frame rate.

14. An apparatus for creating one or more high dynamic range (HDR) images using a stereoscopic camera, the apparatus comprising:

a subsystem, at least partly implemented in hardware, that captures a scene using a stereoscopic camera with a synopter;

a subsystem, at least partly implemented in hardware, that generates from the captured scene a first input image and a second input image, wherein the second input image uses a different exposure than the first input image; and

a subsystem, at least partly implemented in hardware, that combines said two input images into a single output image.

15. The apparatus of claim 14, further comprising a subsystem, at least partly implemented in hardware, that filters an optical path between a lens and one of the sensors of the stereoscopic camera.

16. The apparatus of claim 15, wherein the optical path is filtered using a neutral density filter.

17. The apparatus of claim 14, wherein the synopter is located in front of the lenses and the sensors of the stereoscopic camera.

18. The apparatus of claim 14, wherein the synopter is located between the lenses and the sensors of the stereoscopic camera.

19. The apparatus of claim 14, wherein the two input images are generated using a synopter that comprises at least one mirror with unequal reflectance and transmittance ratios.

20. The apparatus of claim 19, wherein the mirror with unequal reflectance and transmittance ratio comprises at least one of a partially silvered mirror or an electronic mirror.

21. The apparatus of claim 20, wherein the ratio of reflectance to transmittance ratios of the mirror is approximately 80%:

20%.

22. An apparatus for creating one or more high dynamic range (HDR) stereoscopic images using a standard dynamic range (SDR) stereoscopic camera, the apparatus comprising:

a subsystem, at least partly implemented in hardware, that captures a stereoscopic SDR image;

a subsystem, at least partly implemented in hardware, that captures a monoscopic HDR image using a stereoscopic camera with a synopter;

a subsystem, at least partly implemented in hardware, that generates an image depth map from said captured stereoscopic SDR image;

a subsystem, at least partly implemented in hardware, that combines said depth map, said stereoscopic SDR stereoscopic image, and said monoscopic HDR image; and

,

a subsystem, at least partly implemented in hardware, that creates an output stereoscopic HDR image based on the combining step.

23. The apparatus of claim 22, further comprising:

a subsystem, at least partly implemented in hardware, that motion compensates the captured monoscopic HDR image in relation to the captured SDR stereoscopic image before the combining step is performed.

24. The apparatus of claim 22, further comprising:

a subsystem, at least partly implemented in hardware, that motion compensates the captured stereoscopic SDR images in relation to the captured monoscopic input HDR image before the combining step is performed.

25. The apparatus of claim 22, wherein the synopter further comprises two electronic mirrors, wherein the two electronic mirrors switch between a reflective mode and a transmissive mode.

26. The apparatus of claim 25, wherein the two electronic mirrors switch between the reflective mode and the transmissive mode at a rate that is two or more times higher than a desired output frame rate.