EFFICIENT CODING OF DEPTH TRANSITIONS IN 3D (VIDEO)

• US 20120229603A1
• Filed: 11/08/2010
• Published: 09/13/2012
• Est. Priority Date: 11/13/2009
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Bruls, Wilhelmus Hendrikus Alfonsus, Varekamp, Christiaan, Klein Gunnewiek, Reinier Bernardus Maria
• Granted Patent: US 10,097,843 B2
• Time in Patent Office: Days
• 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 19/21 with binary alpha-plane coding for video objects, e.g. context-based arithmetic encoding [CAE]
• CPC Class Codes: H04N 19/46 Embedding additional information in the video signal during the compression process H04N19/517, H04N19/68, H04N19/70 take precedence
• CPC Class Codes: H04N 19/597 specially adapted for multi-view video sequence encoding
• CPC Class Codes: H04N 2213/003 Aspects relating to the "2D+depth" image format

Abstract

A method of encoding a video data signal (15) is provided, together with a method for decoding. The encoding comprises providing color information (51) for pixels in an image, providing a depth map with depth information (52) for the pixels, providing transition information (56, 57, 60, 70, 71) being representative of a width (63, 73) of a transition region (61, 72) in the image, the transition region (61, 72) comprising a depth transition (62) and blended pixels in which colors of a foreground object and a background object are blended, and generating (24) the video data signal (15) comprising encoded data representing the color information (51), the depth map (52) and the transition information (56, 57, 60, 70, 71). The decoding comprises using the transition information (56, 57, 60, 70, 71) for determining the width (63, 73) of the transition regions (61, 72) and for determining alpha values (53) for pixels inside the transition regions (61, 72). The determined alpha values (53) are used for determining the color of a blended pixel at the transition of a foreground object and a background object.

Claims

1. A method of encoding a video data signal (15), the method comprising:

providing color information (51) for pixels in an image,

providing a depth map with depth information (52) for the pixels,

providing transition information (56, 57, 60, 70, 71) being representative of a width (63, 73) of a transition region (61, 72) in the image, the transition region (61, 72) comprising a depth transition (62) and blended pixels in which colors of a foreground object and a background object are blended,

generating (24) the video data signal (15) comprising encoded data representing the color information (51), the depth map (52) and the transition information (56, 57, 60, 70, 71).

2. A method of encoding a video data signal (15) as claimed in claim 1, wherein the transition information comprises a width map (60) defining for the depth transition (62) a corresponding width as a number of blended pixels.

3. A method of encoding a video data signal (15) as claimed in claim 1, wherein the transition information comprises a binary map (70, 71) indicating for each pixel in the image whether it is in the transition region (72) or not.

4. A method of encoding a video data signal (15) as claimed in claim 3, wherein the binary map (71) has a lower resolution than the image.

5. A method of encoding a video data signal (15) as claimed in claim 1, wherein the transition information (56, 57) comprises a table with width parameters (56, 75) for different transition depths.

6. A method of encoding a video data signal (15) as claimed in claim 5, wherein the transition depths are defined as a depth of the foreground object at the depth transition.

7. A method of encoding a video signal (15) as claimed in claim 5, wherein the transition depths are defined as a combination of the depths of the foreground object and the background object at the depth transition.

12. A computer program product for encoding a video data signal, which program is operative to cause a processor to perform the method as claimed in claim 1.

8. A method of decoding a video data signal (15), the video data signal (15) comprising encoded data representing color information (51) for pixels in an image, a depth map with depth information (52) for the pixels and transition information (56, 57, 60, 70, 71) being representative of a width (63, 73) of a transition region (61, 72) comprising a depth transition (62) and blended pixels in which colors of a foreground object and a background object are blended, the method comprising:

receiving the video data signal (41),

based on the transition information (56, 57, 60, 70, 71), determining the width (63, 73) of the transition region (61, 72),

based on the width of the transition region, determining alpha values (53) of the blended pixels, the alpha value (53) of the blended pixels being dependent on a distance to the depth transition (62),

based on the alpha values (53) and the color information (51) determining a color of the blended pixels.

9. A method of decoding a video data signal (15) as claimed in claim 8, wherein the determining of the alpha values (53) is further based on a depth (52) of the depth transition (62).

13. A computer program product for decoding a video data signal, which program is operative to cause a processor to perform the method as claimed in claim 8.

10. An encoder (10) for encoding a video data signal (15), the encoder comprising:

means for providing color information (51) for pixels in an image, a depth map with depth information (52) for the pixels and transition information (56, 57, 60, 70, 71) being representative of a width (63, 73) of a transition region (61, 72) comprising a depth transition (62) and blended pixels in which colors of a foreground object and a background object are blended,

means for generating the video data signal (15) comprising encoded data representing the color information (51), the depth information (52) and the transition information, and

an output for providing the video data signal (15).

11. A decoder (30) for decoding a video data signal (15), the decoder (30) comprising:

an input for receiving a video data signal (15), the video data signal (15) comprising encoded data representing color information (51) for pixels in an image, a depth map with depth information (52) for the pixels and transition information (56, 57, 60, 70, 71) being representative of a width (63, 73) of a transition region (61, 72) comprising a depth transition (62) and blended pixels in which colors of a foreground object and a background object are blended,

means for, based on the transition information (56, 57, 60, 70, 71), determining the width (63, 73) of the transition region (61, 72),

means for, based on the width (63, 73) of the transition region (61, 72), determining alpha values (53) of the blended pixels, the alpha values (53) of the blended pixels being dependent on a distance to the depth transition (62), and

means for, based on the alpha values (53) and the color information (51), determining a color of the blended pixels.

14. A video data signal (15) comprising encoded data representing color information (51) for pixels in an image, a depth map with depth information (52) for the pixels and transition information (56, 57, 60, 70, 71) being representative of a width (63, 73) of a transition region (61, 72) comprising a depth transition (62) and blended pixels in which colors of a foreground object and a background object are blended.

15. A digital data carrier having encoded thereon a video data signal (15) as claimed in claim 14.