Concept for determining a measure for a distortion change in a synthesized view due to depth map modifications
An apparatus for determining a measure for a distortion change of a first view synthesized from a second view, caused by a modification of a depth map of the second view from a first state to a second state, is configured—starting from a current synthesis state of the first view corresponding to a synthesis from the second view having the depth map modified to the second state in an already processed portion of the depth map and having the depth map unmodified at the first state in a yet to be processed portion of the depth map—to compute a possible successor synthesis state corresponding to a synthesis of the first view from the second view having the depth map modified to the second state in an already processed portion plus a currently processed portion and having the depth map unmodified at the first state in the yet to be processed portion without the currently processed portion; and to determine a distortion change of a distortion of the current synthesis state of the first view relative to an undistorted version of the first view to a distortion of the possible successor synthesis state of the first view relative to the undistorted version of the first view.
1. An encoder for coding a video comprising:
a texture encoding mechanism configured for encoding, using a processor, a texture sample array of a view of a video;
a depth encoding mechanism configured for encoding, using the processor, a depth map associated with a view of the video; and
a distortion measurement mechanism configured for determining, using the processor, a distortion change of a first view of the video synthesized from a second view of the video, wherein the distortion change is caused by a modification to the depth map of the second view and is based on at least two synthesis states of the first view corresponding to synthesis of the first view based on the depth map of the second view.
2. The encoder according to claim 1 , the distortion measurement mechanism is configured for obtaining an undistorted version of the first view in accordance with a synthesis of the first view from the second view based on the depth map of the second view in a non-coded state.
3. The encoder according to claim 1 , wherein the distortion measurement mechanism is configured for obtaining and determining with regard to a section of the first view within which changes occur between a first synthesis state and a second synthesis state of the first view.
4. The encoder according to claim 1 , wherein the distortion measurement mechanism is configured for using a per-pixel difference measure for determining the distortion of the respective synthesis state.
5. The encoder according to claim 1 , wherein the distortion measurement mechanism is configured for warping texture samples of a currently coded portion from the second view into the first view using a coded state of the depth map of the second view and determining the distortion of a second synthesis state of the first view based the warped texture samples.
6. The encoder according to claim 5 , wherein the distortion measurement mechanism is configured for, interpolating the warped texture samples onto sample positions of the first view.
7. A decoder for decoding a video comprising:
a texture decoding mechanism configured for decoding, using a processor, a texture sample array of a first view of a video; and
a depth decoding mechanism configured for decoding, using the processor, a depth map associated with the first view of the video,
wherein information related to the first view is used to determine a distortion change of a second view of the video, the second view is synthesized from the first view of the video, the distortion change is caused by a modification to the depth map of the first view and is based on at least two synthesis states of the second view corresponding to synthesis of the second view based on the depth map of the first view.
8. The decoder according to claim 7 , an undistorted version of the second view is obtained in accordance with a synthesis of the second view based on the depth map of the first view in a non-coded state of the depth map.
9. The decoder according to claim 7 , wherein the distortion change of the second view is determined at least by:
obtaining first and second synthesis states of the second view, the first synthesis state corresponding to a synthesis of the second view based on the depth map of the first view comprising a first portion in a coded state and a second portion in a non-coded state, and the second synthesis state corresponding to a synthesis of the second view based on the depth map of the first view including the first portion and a currently encoded portion of the second portion both in the coded state, and
determining the distortion change based on first and second distortion measures with respect to the first and second synthesis states of the second view, respectively, wherein the first and second distortion measures are determined relative to an undistorted version of the first view,
wherein the steps of obtaining and determining are performed with regard to a section of the second view within which changes occur between the first synthesis state and the second synthesis state.
10. The decoder according to claim 9 , wherein the step of determining includes use a per-pixel difference measure for determining the distortion of the respective synthesis state.
11. The decoder according to claim 9 , wherein the distortion change of the second view is determined further by warping texture samples of the currently encoded portion from the first view into the second view using the coded state of the depth map of the first view and determining the distortion of the second synthesis state of the second view based on the warped texture samples.
12. The decoder according to claim 11 , wherein the warped texture samples are interpolated onto sample positions of the second view.
13. The decoder according to claim 12 , wherein the interpolation includes hole filling or blending with another view of the video.
14. A method of decoding a video comprising:
decoding a texture sample array of a first view of a video;
decoding, using a processor, a depth map associated with the first view of the video; and
determining, based on information related to the first view, a distortion change of a second view of the video, wherein the second view being synthesized from the first view of the video, the distortion change is caused by a modification to the depth map of the first view and is based on at least two synthesis states of the second view corresponding to synthesis of the second view based on the depth map of the first view.
15. The method according to claim 14 , further comprising obtaining an undistorted version of the second view in accordance with a synthesis of the second view based on the depth map of the first view in a non-coded state.
16. The method according to claim 14 , wherein the distortion change of the second view is determined at least by:
obtaining first and second synthesis states of the second view, the first synthesis state corresponding to a synthesis of the second view based on the depth map of the first view comprising a first portion in a coded state and a second portion in a non-coded state, and the second synthesis state corresponding to a synthesis of the second view based on the depth map of the first view including the first portion and a currently encoded portion of the second portion both in the coded state, and
determining the distortion change based on first and second distortion measures with respect to the first and second synthesis states of the second view, respectively, wherein the first and second distortion measures are determined relative to an undistorted version of the first view,
wherein the steps of obtaining and determining are performed with regard to a section of the second view within which changes occur between the first synthesis state and the second synthesis state.
17. The method according to claim 16 , wherein the step of determining includes use a per-pixel difference measure for determining the distortion of the respective synthesis state.
18. The method according to claim 16 , wherein the determining the distortion change further comprises warping texture samples of the currently encoded portion from the first view into the second view using the coded state of the depth map of the first view, and determining the distortion of the second synthesis state of the second view based on the warped texture samples.
19. The method according to claim 18 , further comprising interpolating the warped texture samples onto sample positions of the second view.
20. The method according to claim 19 , wherein the interpolation includes hole filling or blending with another view of the video.