Method and apparatus for simplified depth coding with extended prediction modes
A method and apparatus for Simplified Depth Coding (SDC) with extended Intra prediction modes are disclosed. Embodiments of the present invention use an extended Intra prediction mode set including Horizontal mode and Vertical mode. When the Horizontal mode is selected, the prediction samples for the current depth block are derived based on a reconstructed neighboring depth column adjacent to a left block boundary of the current depth block by generating rows of the prediction samples from the reconstructed neighboring depth column. When the Vertical mode is selected, the prediction samples for the current depth block are derived based on a reconstructed neighboring depth row adjacent to a top block boundary of the current depth block by generating columns of the prediction samples from the reconstructed neighboring depth row.
1. A method of Intra coding for a depth block in a three-dimensional coding system, the method comprising:
receiving input data associated with a current depth block;
determining a current Intra prediction mode for the current depth block, wherein the current Intra prediction mode belongs to a mode set comprising Horizontal mode and Vertical mode;
deriving prediction samples for the current depth block based on reconstructed neighboring depth samples according to the current Intra prediction mode, wherein said deriving prediction samples uses a reconstructed neighboring depth column adjacent to a left block boundary of the current depth block to perform horizontal prediction by generating rows of the prediction samples from the reconstructed neighboring depth column if the Horizontal mode is selected, and wherein said deriving prediction samples uses a reconstructed neighboring depth row adjacent to a top block boundary of the current depth block to perform vertical prediction by generating columns of the prediction samples from the reconstructed neighboring depth row if the Vertical mode is selected; and
applying Simplified Depth Coding (SDC) to the current depth block using the prediction samples derived for the current depth block.
2. The method of claim 1 , wherein the mode set further comprises Planar mode and DMM (Depth Modelling Mode) mode.
3. The method of claim 1 , wherein the Intra prediction modes in the mode set are coded using a truncated unary code.
4. The method of claim 1 , wherein a predicting depth value representing a single prediction value for the current depth block is determined based on two corner prediction samples of a left-most column of the current depth block if the Horizontal mode is selected.
5. The method of claim 1 , wherein a predicting depth value representing a single prediction value for the current depth block is determined based on all reconstructed samples, one reconstructed samples, partial reconstructed samples, or two corner reconstructed samples of the reconstructed neighboring depth column adjacent to the left block boundary of the current depth block if the Horizontal mode is selected.
6. The method of claim 1 , wherein a predicting depth value representing a single prediction value for the current depth block is determined based on two corner prediction samples of a top row of the current depth block if the Vertical mode is selected.
7. The method of claim 1 , wherein a predicting depth value representing a single prediction value for the current depth block is determined based on all reconstructed samples, one reconstructed samples, partial reconstructed samples, or two corner reconstructed samples of the reconstructed neighboring depth row adjacent to the top block boundary of the current depth block if the Vertical mode is selected.
8. The method of claim 1 , wherein a predicting depth value representing a single prediction value for the current depth block is determined based on four corner prediction samples of the current depth block.
9. The method of claim 1 , wherein a predicting depth value representing a single prediction value for the current depth block is determined based on all prediction samples, sub-sampled prediction samples, or a subset of the prediction samples of the current depth block.
10. The method of claim 9 , wherein the predicting depth value is determined using a mean, median, maximum, minimum, or linear combination of said all prediction samples, the sub-sampled prediction samples, or the subset of the prediction samples of the current depth block.
11. The method of claim 9 , wherein the predicting depth value is determined using a mean of four corner prediction samples of the current depth block.
12. The method of claim 1 , wherein a predicting depth value representing a single prediction value for the current depth block if the Horizontal mode is selected and the single prediction value is determined based on a first subset of the prediction samples, wherein a second subset of the prediction samples different from the first subset is used to determine one or more single prediction values for the current depth block if a different mode is used, and wherein the first subset corresponds to one prediction sample, two corner prediction samples or all prediction samples located in a selected column of the current depth block.
13. The method of claim 12 , wherein the selected column corresponds to a left-most column of the current depth block.
14. The method of claim 1 , wherein a predicting depth value representing a single prediction value for the current depth block if the Vertical mode is selected and the single prediction value is determined based on a first subset of the prediction samples, wherein a second subset of the prediction samples different from the first subset is used to determine one or more single prediction values for the current depth block if a different mode is used, and wherein the first subset corresponds to one prediction sample, two corner prediction samples or all prediction samples located in a selected row of the current depth block.
15. The method of claim 14 , wherein the select row corresponds to a top row of the current depth block.
16. An apparatus for Intra coding of a depth block in a three-dimensional coding system, the apparatus comprising one or more electronic circuits configured to:
receive input data associated with a current depth block;
determine a current Intra prediction mode for the current depth block, wherein the current Intra prediction mode belongs to a mode set comprising Horizontal mode and Vertical mode;
derive prediction samples for the current depth block based on reconstructed neighboring depth samples according to the current Intra prediction mode, wherein if the Horizontal mode is selected, said one or more electronic circuits are configured to derive prediction samples using a reconstructed neighboring depth column adjacent to a left block boundary of the current depth block by generating rows of the prediction samples from the reconstructed neighboring depth column, and wherein if the Vertical mode is selected, said one or more electronic circuits are configured to derive prediction samples using a reconstructed neighboring depth row adjacent to a top block boundary of the current depth block by generating columns of the prediction samples from the reconstructed neighboring depth row; and
apply Simplified Depth Coding (SDC) to the current depth block using the prediction samples derived for the current depth block.