摘要:
A method and apparatus of Intra mode coding for a scalable video coding system are disclosed. For a current Intra-coded block in the enhancement layer (EL), predictive coding is applied to the current Intra mode based on the base layer (BL) coding mode associated with the co-located block in the BL and neighboring coding modes associated with neighboring blocks of the current block in the EL. The neighboring blocks of the current block in the EL comprise a left block adjacent to a left side of the current block and a top block adjacent to a top side of the current block. One or more most probable modes (MPMs) can be derived from the neighboring coding modes and the BL coding mode, and the MPMs is then used for predictive coding of the current Intra mode.
摘要:
A method and apparatus of Intra mode coding for a scalable video coding system are disclosed. For a current Intra-coded block in the enhancement layer (EL), predictive coding is applied to the current Intra mode based on the base layer (BL) coding mode associated with the co-located block in the BL and neighboring coding modes associated with neighboring blocks of the current block in the EL. The neighboring blocks of the current block in the EL comprise a left block adjacent to a left side of the current block and a top block adjacent to a top side of the current block. One or more most probable modes (MPMs) can be derived from the neighboring coding modes and the BL coding mode, and the MPMs is then used for predictive coding of the current Intra mode.
摘要:
A method and apparatus for intra prediction for a current block using directional intra prediction based on neighboring pixels around the current block are disclosed. Embodiment according to the present invention derives the gradient for the current pixel from the neighboring reconstructed pixels along a prediction direction of directional intra prediction. The gradient derived is used to form the final intra prediction. In another embodiment of the present invention, the intra prediction for slant vertical and horizontal directions is derived based on the neighboring reconstructed pixels in a neighboring row adjacent to the top side of the current block and the neighboring reconstructed pixels in a neighboring column adjacent to the left side of the current block.
摘要:
A method and apparatus for improved intra chroma prediction mode coding are disclosed. Intra prediction exploits the spatial correlation within a picture or within a picture region. In practice, a picture is divided into blocks and the intra mode prediction is performed on a block basis. In newer coding systems, multiple intra coding modes such as Vertical mode, Horizontal mode, DC mode and Diagonal mode, have been used to improve the coding efficiency of intra coding. Furthermore, a Luma_mode has also been used in intra prediction of chroma component to further improve the performance in the High Efficiency Video Coding (HEVC) standard being developed. However, the mode selection information for intra prediction has to be conveyed to the decoder for proper operation. Spatial features in a picture often exist in both luma and chroma components. The intra luma prediction mode and intra chroma prediction mode will have high probability to be the same. Accordingly, an embodiment according to the present invention adaptively assigns variable length codes to a set of mode symbols associated with intra chroma prediction by assigning a shortest code to the Luma_mode. Luma_mode not only can be the best luma mode of the corresponding luma block but also can be selected from several corresponding luma modes. The maximum length of chroma prediction codes is decreased by one bit when Luma_mode is equal to one of frequent modes. The coding efficiency of arithmetic coding of chroma prediction codes is further improved by selecting the context upon neighboring blocks.
摘要:
A method and apparatus for chroma intra prediction for a current chroma block with reduced line memory requirement are disclosed. The chroma intra predictor is derived from reconstructed luma pixels of a current luma block using a model with parameters. In various embodiments according to the present invention, the derivation of the parameters relies on a reconstructed luma pixel set corresponding to neighboring reconstructed luma pixels from causal luma neighboring areas of the current luma block, wherein said causal luma neighboring areas include a first area corresponding to reconstructed luma pixels above a horizontal luma block boundary on a top side of the current luma block, and wherein the reconstructed luma pixels from the first area that are included in the reconstructed luma pixel set are from a luma pixel line immediately above the horizontal luma block boundary.
摘要:
Method and apparatus for intra prediction mode coding and decoding are disclosed. In one embodiment, the encoding and decoding process assigns individual indices and codewords to DC mode and Planar mode respectively. The flag is set if the current intra prediction mode is equal to any of one or more neighboring intra prediction modes. Variable length codes are designed for a remaining mode set. If the flag is not set, the currently intra prediction mode is encoded using the variable length codes. In another embodiment, multiple most probable modes are used. If the current intra prediction mode is not equal to any of the multiple most probable modes, the current intra prediction mode is encoded using variable length codes designed for the corresponding remaining modes according the ranking order of the remaining modes.
摘要:
A method and apparatus for intra prediction for a current block using directional intra prediction based on neighboring pixels around the current block are disclosed. Embodiment according to the present invention derives the gradient for the current pixel from the neighboring reconstructed pixels along a prediction direction of directional intra prediction. The gradient derived is used to form the final intra prediction. In another embodiment of the present invention, the intra prediction for slant vertical and horizontal directions is derived based on the neighboring reconstructed pixels in a neighboring row adjacent to the top side of the current block and the neighboring reconstructed pixels in a neighboring column adjacent to the left side of the current block.
摘要:
A method and apparatus for improved intra prediction mode coding are disclosed. Intra prediction exploits the spatial correlation within a picture or within a picture region. In High-Efficiency Video Coding (HEVC), a coding scheme for the intra luma prediction mode is considered, where the intra prediction mode of a current block is compared with the minimum of two intra luma prediction modes corresponding to two neighboring blocks. If the intra prediction mode of the current block is the same as the minimum of the two neighboring intra luma prediction modes, a single bit is transmitted to indicate the case. Otherwise, information for the current intra prediction mode is transmitted in fixed-length codeword. The present invention provides multiple intra prediction mode candidates based on neighboring intra prediction modes so that there is a better chance for predictor hit. Accordingly, improved coding efficiency is achieved.
摘要:
Method and apparatus for intra prediction mode coding and decoding are disclosed. In one embodiment, the encoding and decoding process assigns individual indices and codewords to DC mode and Planar mode respectively. The flag is set if the current intra prediction mode is equal to any of one or more neighboring intra prediction modes. Variable length codes are designed for a remaining mode set. If the flag is not set, the currently intra prediction mode is encoded using the variable length codes. In another embodiment, multiple most probable modes are used. If the current intra prediction mode is not equal to any of the multiple most probable modes, the current intra prediction mode is encoded using variable length codes designed for the corresponding remaining modes according the ranking order of the remaining modes.
摘要:
A method and apparatus for improved intra chroma prediction mode coding are disclosed. Intra prediction exploits the spatial correlation within a picture or within a picture region. In practice, a picture is divided into blocks and the intra mode prediction is performed on a block basis. In newer coding systems, multiple intra coding modes such as Vertical mode, Horizontal mode, DC mode and Diagonal mode, have been used to improve the coding efficiency of intra coding. Furthermore, a Luma_mode has also been used in intra prediction of chroma component to further improve the performance in the High Efficiency Video Coding (HEVC) standard being developed. However, the mode selection information for intra prediction has to be conveyed to the decoder for proper operation. Spatial features in a picture often exist in both luma and chroma components. The intra luma prediction mode and intra chroma prediction mode will have high probability to be the same. Accordingly, an embodiment according to the present invention adaptively assigns variable length codes to a set of mode symbols associated with intra chroma prediction by assigning a shortest code to the Luma_mode. Luma_mode not only can be the best luma mode of the corresponding luma block but also can be selected from several corresponding luma modes. The maximum length of chroma prediction codes is decreased by one bit when Luma_mode is equal to one of frequent modes. The coding efficiency of arithmetic coding of chroma prediction codes is further improved by selecting the context upon neighboring blocks.