Method of Depth Coding Compatible with Arbitrary Bit-Depth
A method and apparatus for coding depth data using inter-view motion prediction (IVMP) in a three-dimensional or multi-dimensional video coding system are disclosed. In one embodiment, the bit depth of the depth data associated with the current depth map is determined first and a converted disparity vector is derived from a selected depth value depending on the bit depth. A corresponding depth block in an inter-view reference depth map in a reference view is located using the converted disparity vector. The current depth block is then encoded or decoded using the corresponding depth block as an inter-view predictor.
1 . A method of coding depth data using inter-view motion prediction (IVMP) for a three-dimensional or multi-view video coding system, the method comprising:
receiving input data associated with a current depth block of depth data of a current depth map in a dependent view;
determining a bit depth of the depth data associated with the current depth map;
deriving a converted disparity vector from a selected depth value depending on the bit depth;
locating a corresponding depth block in an inter-view reference depth map in a reference view using the converted disparity vector; and
encoding or decoding the current depth block using the corresponding depth block as an inter-view predictor.
2 . The method of claim 1 , wherein the converted disparity vector is determined from the selected depth value using a lookup table.
3 . The method of claim 1 , wherein the selected depth value, d is calculated according to d=1<<(BitDepth−1), BitDepth corresponds to the bit depth and “<<” corresponds to an arithmetic left shift operation.
4 . The method of claim 3 , wherein the converted disparity vector corresponds to (DepthToDisparityB [d], 0), wherein DepthToDisparityB [] is a lookup function mapping an input depth value to an output disparity vector.
5 . The method of claim 1 , wherein the bit depth of the depth data associated with the current depth map is indicated in a sequence level of a bitstream associated with the depth data.
6 . The method of claim 1 , wherein said determining the converted disparity vector, said locating the corresponding depth block and said encoding or decoding the current depth block using the corresponding depth block as the inter-view predictor are performed only if the bit depth is 8.
7 . The method of claim 1 , wherein said encoding or decoding the current depth block using the corresponding depth block as the inter-view predictor is not performed if the bit depth is not 8.
8 . The method of claim 1 , wherein a bitstream associated with the depth data is invalid if the bitstream indicates that inter-view motion prediction is applied to the depth data and the bit depth is not 8.
9 . An apparatus for coding depth data using inter-view motion prediction (IVMP) for a three-dimensional or multi-view video coding system, the apparatus comprising one or more electronic circuits configured to:
receive input data associated with a current depth block of depth data of a current depth map in a dependent view;
determine a bit depth of the depth data associated with the current depth map;
determine a converted disparity vector from a selected depth value depending on the bit depth;
locate a corresponding depth block in a reference depth map in a reference view using the converted disparity vector; and
encode or decode the current depth block using the corresponding depth block as an inter-view predictor.
10 . The apparatus of claim 9 , wherein the converted disparity vector is determined from the selected depth value using a lookup table.
11 . The apparatus of claim 9 , wherein the selected depth value, d is calculated according to d=1<<(BitDepth−1), BitDepth corresponds to the bit depth and “<<” corresponds to an arithmetic left shift operation.
12 . The apparatus of claim 11 , wherein the converted disparity vector corresponds to (DepthToDisparityB [d], 0), wherein DepthToDisparityB [] is a lookup function mapping an input depth value to an output disparity vector.
13 . The apparatus of claim 9 , wherein the bit depth of the depth data associated with the current depth map is indicated in a sequence level of a bitstream associated with the depth data.
14 . The apparatus of claim 9 , wherein said determining the converted disparity vector, said locating the corresponding depth block and said encoding or decoding the current depth block using the corresponding depth block as the inter-view predictor are performed only if the bit depth is 8.
15 . The apparatus of claim 9 , wherein said encoding or decoding the current depth block using the corresponding depth block as the inter-view predictor is not performed if the bit depth is not 8.
16 . The apparatus of claim 9 , wherein a bitstream associated with the depth data is invalid if the bitstream indicates that inter-view motion prediction is applied to the depth data and the bit depth is not 8.