GENERATION OF A DEPTH MAP FROM A MONOSCOPIC COLOR IMAGE FOR RENDERING STEREOSCOPIC STILL AND VIDEO IMAGES

• US 20080247670A1
• Filed: 04/02/2008
• Published: 10/09/2008
• Est. Priority Date: 04/03/2007
• Status: Active Grant

• Current Assignee: Her Majesty The Queen In Right Of Canada, As Represented By The Minister Of Industry, Through The Communications Research Centre Canada
• Original Assignee: Her Majesty The Queen In Right Of Canada, As Represented By The Minister Of Industry, Through The Communications Research Centre Canada
• Inventors: TAM, Wa James, Vazquez, Carlos
• Granted Patent: US 8,488,868 B2
• Time in Patent Office: Days
• US Class Current: 382/298
• CPC Class Codes: G06T 7/50 Depth or shape recovery
• CPC Class Codes: H04N 13/257 Colour aspects
• CPC Class Codes: H04N 13/261 with monoscopic-to-stereoscopic image conversion

Abstract

The invention relates to a method and an apparatus for generating a depth map from a digital monoscopic color image. The method includes the following general steps: a) obtaining a first color component of the MCI, said first color component corresponding to partial color information of the MCI; and, b) assigning depth values to pixels of the MCI based on values of the first color component of respective pixels for forming the depth map for the MCI. In one embodiment, the depth values are generated by adjusting and/or scaling of pixel values of the Cr chroma component of the monoscopic source color image in the Y′CbCr color system.

Claims

1. A method of generating a depth map from a monoscopic color image (MCI) composed of pixels, the method comprising the steps of:

a) obtaining a first color component of the MCI, said first color component corresponding to partial color information of the MCI; and

,

b) assigning depth values to pixels of the MCI based on values of the first color component of respective pixels for forming the depth map for the MCI.

2. A method according to claim 1, wherein the depth values are obtained by scaling respective pixel values of the first color component.

3. A method according to claim 2, wherein the first color component is the Cr chroma component of the MCI in the Y′

CbCr color system.

4. A method according to claim 1, wherein step (b) comprises the step of

c) selectively adjusting pixel values of the first color component in a portion of the MCI.

5. A method according to claim 4, wherein the portion of the MCI is selected based on pixel values of a second color component of the MCI.

6. A method according to claim 5, wherein the first color component is the Cr chroma component of the MCI in the Y′

CbCr color system, and the second color component is one of red (R) and green (G) color components of the MCI in the RGB color system.

7. A method according to claim 6, wherein the portion of the MCI comprises one of:

first pixels having R values satisfying a pre-determined red threshold criterion, and second pixels having G values satisfying a pre-determined green threshold criterion.

8. A method according to claim 7, wherein the pre-determined red threshold criterion comprises at least one of:

determining if the red intensity values exceed a threshold value,

determining if the red intensity values minus green intensity values exceed a threshold value, and

determining if the blue intensity values minus green intensity values exceed a threshold value,

and wherein the pre-determined green threshold criterion comprises determining if the green intensity values exceed a threshold value.

9. A method according to claim 7, wherein step (b) comprises one of:

selectively reducing values of the first color component for the first pixels, and selectively enhancing values of the first color component for the second pixels.

10. A method according to claim 1, further comprising the step of smoothing the depth map.

11. A method according to claim 10, wherein the step of smoothing the depth map comprises applying a 2D Gaussian filter thereto.

12. A method according to claim 2, wherein the first color component is one of chroma components of the MCI in the Y′

CbCr color system or one of chroma components of the MCI in the CMYK color system.

13. A method of generating a multi-view image comprising the step of:

a. receiving a monoscopic color image (MCI) composed of pixels;

b. generating a depth map from the MCI based on a color component thereof, said color component corresponding to partial color information of the MCI;

c. utilizing a depth image based rendering (DIBR) algorithm to create at least one deviated image by processing the MCI based on the depth map, so as to form a stereoscopic image pair.

14. A 3D image generating apparatus comprising:

a data receiver for receiving data representing a monoscopic color image (MCI) composed of pixels;

a depth map generator for generating a depth map comprising pixel depth values based on a first color component of the MCI; and

,

a DIBR processor for processing the MCI based on the depth map to render at least one deviated image for forming at least one stereoscopic image pair.

15. A 3D image generating apparatus according to claim 14, further comprising a multi-view display for generating at least one stereoscopic view from the at least one stereoscopic image pair.

16. A 3D image generating apparatus according to claim 14, wherein:

the depth map generator comprises a scaling unit for scaling pixel values of the first color component for producing the pixel depth values.

17. A 3D image generating apparatus according to claim 16, wherein the depth map generator further comprises:

a color processor for obtaining a second color component from the MCI;

a color adjuster for selectively adjusting pixel values of the first color component based on pixel values of the second color component for respective pixels.

18. A 3D image generating apparatus according to claim 16, wherein the color processor is for obtaining the first color component from the MCI.

19. An apparatus for generating 3D motion pictures from a sequence of monoscopic color images, comprising a 3D image generating apparatus according to claim 15 for generating and sequentially displaying at least one stereoscopic view from each monoscopic color image from the sequence of the monoscopic color images.