Apparatus and method for determining a disparity estimate

• US 9,591,281 B2
• Filed: 06/30/2011
• Issued: 03/07/2017
• Est. Priority Date: 12/22/2010
• Status: Active Grant

• Current Assignee: Thomson Licensing (Vantiva SA)
• Original Assignee: Thomson Licensing (Vantiva SA)
• Inventors: Schlosser, Markus, Jachalsky, Jorn, Ostermann, Ralf
• Primary Examiner(s): Shah, Utpal
• Application Number:
  US13/995,602
• Publication Number:
  US 20130272582A1
• Time in Patent Office: 2,077 Days
• US Class Current: 1/1
• CPC Class Codes: G06T 2207/10021 Stereoscopic video; Stereoscopic image sequence
• CPC Class Codes: G06T 7/593 from stereo images
• CPC Class Codes: H04N 13/128 Adjusting depth or disparity
• CPC Class Codes: H04N 13/156 Mixing image signals
• CPC Class Codes: H04N 13/183 On-screen display [OSD] information, e.g. subtitles or menus

Abstract

The invention relates to a method and an apparatus for determining a disparity value for an object located in or to be placed into a stereoscopic image pair having an associated disparity map. First an area to be analyzed in one of the stereoscopic images is determined Then a histogram is built from disparity estimates of the associated disparity map that fall within the determined area. Subsequently a contiguous range of bins is searched in the histogram that also contains a sufficient number of pixels. Finally, a disparity estimate for the determined area is selected from the contiguous range of histogram bins.

Claims

1. A method for determining a disparity value for an object located in or to be placed into a stereoscopic image pair, the stereoscopic image pair having an associated disparity map having disparity estimates for individual pixels of the stereoscopic image pair, the method comprising:

determining an area to be analyzed in one of the stereoscopic images;

retrieving those disparity estimates from the associated disparity map that are associated with pixels of the stereoscopic image pair that lie within the determined area;

building a histogram from the retrieved disparity estimates;

searching a contiguous range of histogram bins, each histogram bin of the contiguous range containing at least a specified minimum number of disparity estimates and the contiguous range containing in total at least a specified number of disparity estimates; and

selecting a disparity estimate for the determined area from the contiguous range of histogram bins.

2. The method according to claim 1, wherein only those disparity estimates from the associated disparity map that are associated with pixels of the stereoscopic image pair that lie within the determined area are used to build the histogram for which an associated confidence measure exceeds a defined threshold.

3. The method according to claim 1, wherein said building a histogram further comprises accumulating associated confidence measures of the disparity estimates, or a value derived from the associated confidence measures of the disparity estimates.

4. The method according to claim 1, wherein the determined disparity estimate is used to adapt the stereoscopic image pair to a display.

5. The method according to claim 1, wherein the area to be analyzed in one of the stereoscopic images is the complete stereoscopic image.

6. The method according to claim 1, wherein the contiguous range farthest from a viewer is searched in the histogram.

7. The method according to claim 1, wherein the contiguous range closest to a viewer is searched in the histogram.

8. The method according to claim 7, wherein the area to be analyzed in one of the stereoscopic images is determined by the area of one or more graphics objects to be placed into the stereoscopic image pair.

9. The method according to claim 8, wherein the graphics object is a menu item, a score board, a logo or a subtitle.

10. The method according to claim 1, wherein the disparity estimate for the determined area is selected as the disparity for which the collected number of pixels surpasses the threshold or a fraction of the threshold, as a function of the absolute minimum, mean or maximum of the found contiguous range, or as a function of the maximum or median of a sub-historgram for this contiguous range.

11. The method according to claim 1, further comprising subdividing the determined area to be analyzed.

12. An apparatus for determining a disparity value for an object located in or to be placed into a stereoscopic image pair, the stereoscopic image pair having an associated disparity map having disparity estimates for individual pixels of the stereoscopic image pair, wherein the apparatus comprises:

a graphics analyzing block configured to determine an area to be analyzed in one of the stereoscopic images;

a histogram building block configured to retrieve those disparity estimates from the associated disparity map that are associated with pixels of the stereoscopic image pair that lie within the determined area and to build a histogram from the retrieved disparity estimates;

a searching block configured to search a contiguous range of histogram bins, each histogram bin of the contiguous range containing at least a specified number of disparity estimates and the contiguous range containing in total at least a specified number of disparity estimates; and

a disparity estimation block configured to select a disparity estimate for the determined area from the contiguous range of histogram bins.

13. The apparatus according to claim 12, wherein the histogram building block is configured to use only those disparity estimates from the associated disparity map that are associated with pixels of the stereoscopic image pair that lie within the determined area to build the histogram for which an associated confidence measure exceeds a defined threshold.

14. The apparatus according to claim 12, wherein the histogram building block is configured to build the histogram by accumulating associated confidence measures of the disparity estimates, or a value derived from the associated confidence measures of the disparity estimates.

15. The apparatus according to claim 12, wherein the apparatus is configured to use the determined disparity estimate to adapt the stereoscopic image pair to a display.

16. The apparatus according to claim 12, wherein the area to be analyzed in one of the stereoscopic images is the complete stereoscopic image.

17. The apparatus according to claim 12, wherein the searching block is configured to search the contiguous range farthest from a viewer in the histogram.

18. The apparatus according to claim 12, wherein the searching block is configured to search the contiguous range closest to a viewer in the histogram.

19. The apparatus according to claim 18, wherein the area to be analyzed in one of the stereoscopic images is determined by the area of one or more graphics objects to be placed into the stereoscopic image pair.

20. The apparatus according to claim 19, wherein the graphics object is a menu item, a score board, a logo or a subtitle.

21. The apparatus according to claim 12, wherein the disparity estimation block is configured to select the disparity estimate for the determined area as the disparity for which the collected number of pixels surpasses the threshold or a fraction of the threshold, as a function of the absolute minimum, mean or maximum of the found contiguous range, or as a function of the maximum or median of a sub-histogram for this contiguous range.

22. The apparatus according to claim 12, wherein the graphics analyzing block is configured to subdivide the determined area to be analyzed.