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 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 , wherein the distortion measurement mechanism is configured to:
obtain first and second synthesis states of the first view, the first synthesis state corresponding to a synthesis of the first view from the second view based on the depth map of the second view comprising a first portion in a modified state and a second portion in an unmodified state, and the second synthesis state corresponding to a synthesis of the first view from the second view based on the depth map of the second view comprising the first portion and a currently processed portion in the modified state and the second portion without the currently processed portion in the unmodified state.
3. The encoder according to claim 2 , 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 the first synthesis state and the 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 2 , 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 the 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 depth decoding mechanism configured for decoding, 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.
8. The decoder according to claim 7 , wherein the distortion measurement mechanism is configured to:
obtain first and second synthesis states of the first view, the first synthesis state corresponding to a synthesis of the first view from the second view based on the depth map of the second view comprising a first portion in a modified state and a second portion in an unmodified state, and the second synthesis state corresponding to a synthesis of the first view from the second view based on the depth map of the second view comprising the first portion and a currently processed portion in the modified state and the second portion without the currently processed portion in the unmodified state.
9. The decoder according to claim 8 , 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 the first synthesis state and the second synthesis state of the first view.
10. The decoder according to claim 7 , wherein the distortion measurement mechanism is configured for using a per-pixel difference measure for determining the distortion of the respective synthesis state.
11. The decoder according to claim 8 , 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 the second synthesis state of the first view based the warped texture samples.
12. The decoder according to claim 11 , wherein the distortion measurement mechanism is configured for, interpolating the warped texture samples onto sample positions of the first view.