System and Method of Processing 3D Stereoscopic Image

• US 20130038600A1
• Filed: 08/12/2011
• Published: 02/14/2013
• Est. Priority Date: 08/12/2011
• Status: Active Grant

• Current Assignee: Himax Technologies Ltd. (Himax Technologies Incorporated)
• Original Assignee: Himax Technologies Ltd. (Himax Technologies Incorporated)
• Inventors: WANG, Tzung-Ren
• Granted Patent: US 8,817,073 B2
• Time in Patent Office: Days
• US Class Current: 345/419
• CPC Class Codes: G06T 15/405 using Z-buffer
• CPC Class Codes: H04N 13/122 Improving the 3D impression of stereoscopic images by modifying image signal contents, e.g. by filtering or adding monoscopic depth cues H04N13/128 takes precedence
• CPC Class Codes: H04N 13/189 Recording image signals; Reproducing recorded image signals
• CPC Class Codes: H04N 19/597 specially adapted for multi-view video sequence encoding
• CPC Class Codes: H04N 2013/0081 Depth or disparity estimation from stereoscopic image signals

Abstract

A 3D stereoscopic image processing system comprises a receiver unit and an image processing unit. The receiver unit is adapted to receive a pair of stereoscopic images. The image processing unit is adapted to compute a first depth map from the pair of stereoscopic images, determine extreme depth values from a window selected in the depth map, determine a filter map based on the extreme depth values, and compute a second depth map by combining the filter map with the first depth map. In other embodiments, a method of processing stereoscopic images is provided, comprising computing a first depth map from a pair of stereoscopic images, generating a filter map associated with the first depth map, and combining the first depth map with the filter map to derive a second depth map.

Claims

1. A stereoscopic image rendering system comprising:

a receiver unit adapted to receive a pair of stereoscopic images; and

an image processing unit adapted to

compute a first depth map from the pair of stereoscopic images;

determine extreme depth values from a window selected in the depth map;

determine a filter map based on the extreme depth values; and

compute a second depth map by combining the filter map with the first depth map.

2. The system according to claim 1, wherein the filter map is defined with a quadratic function expressed by the formulae α

x2+β

x+γ

, wherein α

, β and

γ

are parameters.

3. The system according to claim 2, wherein a minimum of the extreme depth values include a minimal depth value and a maximal depth value, the minimal depth value being assigned to the parameters α

and γ

, and the maximal depth value being assigned to the parameter β

.

4. The system according to claim 1, wherein the second depth map is computed by adding the first depth map applied with a first weight, with the filter map applied with a second weight.

5. The system according to claim 4, wherein the sum of the first weight with the second weight is equal to 1.

6. The system according to claim 1, wherein the window is substantially centered on a middle area of the first depth map.

7. The system according to claim 1, wherein the image processing unit is further adapted to

apply a bidirectional stereo matching method to compute the first depth map from the pair of stereoscopic images;

and

derive the first depth map from the disparity map.

8. The system according to claim 7, wherein the image processing unit is configured to fill an occlusion hole in the disparity map with depth values of a pixel region adjacent to the occlusion hole.

9. The system according to claim 7, wherein the image processing unit is configured to fill a boundary hole in the disparity map with depth values of a pixel region adjacent to the boundary hole.

10. A method of processing stereoscopic images, comprising:

computing a first depth map from a pair of stereoscopic images;

generating a filter map associated with the first depth map; and

combining the first depth map with the filter map to derive a second depth map.

11. The method according to claim 10, wherein the step of generating the filter map comprises:

selecting a window in the first depth map;

determining extreme depth values in the window; and

forming a filter map based on the extreme depth values.

12. The method according to claim 11, wherein the filter map is defined by a filter function F(x)=α

x2+β

x+γ

, wherein α

, β and

γ

are parameters predetermined according to the extreme depth values.

13. The method according to claim 12, wherein the extreme depth values include a minimal depth value and a maximal depth value, the minimal depth value being assigned to α

and γ

, and the maximal depth value being assigned to β

.

14. The method according to claim 11, wherein the window is substantially centered in the first depth map.

15. The method according to claim 10, wherein the step of combining the first depth map with the filter map to derive a second depth map includes:

applying a first weight to the first depth map;

applying a second weight to the filter map; and

adding the weighted first depth map with the weighted filter map.

16. The method according to claim 15, wherein the sum of the first weight with the second weight is equal to 1.

17. The method according to claim 10, wherein the step of computing a first depth map from a pair of stereoscopic images comprises:

applying a bidirectional stereo matching method to compute a disparity map from the pair of stereoscopic images; and

deriving the first depth map from the disparity map.

18. The method according to claim 17, wherein the step of applying a bidirectional stereo matching method to compute the disparity map further includes filling an occlusion hole in the disparity map with depth values of a pixel region adjacent to the occlusion hole.

19. The method according to claim 17, wherein the step of applying a bidirectional stereo matching method to compute the disparity map further includes filling an boundary hole in the disparity map with depth values of a pixel region adjacent to the boundary hole.