An image processing apparatus, including processing circuitry configured to decode a bit stream to generate quantized data. The bit stream includes a flag, for each block, that specifies whether or not a difference quantization parameter is present in the bit stream. The flag is included in a first layer that is higher than a second layer in which the difference quantization parameter is set. The processing circuitry is configured to set, according to the flag, a current quantization parameter for a current sub block formed by block partitioning, which splits a block into smaller sub blocks. The processing circuitry is configured to inversely quantize the generated quantized data using the set current quantization parameter.

Methods of encoding and decoding for video data are described in which multi-level significance maps are used in the encoding and decoding processes. The significant-coefficient flags that form the significance map are grouped into contiguous groups, and a significant-coefficient-group flag signifies for each group whether that group contains no non-zero significant-coefficient flags. A multi-level scan order may be used in which significant-coefficient flags are scanned group-by-group. The group scan order specifies the order in which the groups are processed, and the scan order specifies the order in which individual significant-coefficient flags within the group are processed. The bitstream may interleave the significant-coefficient-group flags and their corresponding significant-coefficient flags, if any.

Methods of encoding and decoding for video data are described in which multi-level significance maps are used in the encoding and decoding processes. The significant-coefficient flags that form the significance map are grouped into contiguous groups, and a significant-coefficient-group flag signifies for each group whether that group contains no non-zero significant-coefficient flags. A multi-level scan order may be used in which significant-coefficient flags are scanned group-by-group. The group scan order specifies the order in which the groups are processed, and the scan order specifies the order in which individual significant-coefficient flags within the group are processed. The bitstream may interleave the significant-coefficient-group flags and their corresponding significant-coefficient flags, if any.

An intra-frame encoding method, an intra-frame decoding method, an encoder, and a decoder, where the intra-frame encoding method includes obtaining reference pixel values of a current picture block obtaining a predicted value of a first-type pixel in the current picture block according to the reference pixel values of the current picture block using an intra-frame prediction algorithm, obtaining residual values of the first-type pixel, obtaining transform coefficients according to the residual values of the first-type pixel, quantizing the transform coefficients, reconstructing the first-type pixel according to the quantized transform coefficients and the predicted value of the first-type pixel, and obtaining a reconstructed value of the second-type pixel according to the reconstructed value of the first-type pixel using an interpolation method. Hence, flexible encoding can be implemented, and encoding efficiency can be improved.

Coding using efficient context handling in arithmetic coding is disclosed. A method for decoding a current block in a scan order includes identifying a current entropy coded transform coefficient from the current block, and entropy decoding the current entropy coded transform coefficient. Entropy decoding the current entropy coded transform coefficient may include determining, based on the scan order, a first scan order distance between a scan order location corresponding to the current entropy coded transform coefficient and a scan order location corresponding to a first context coefficient, identifying a first context coefficient value from a first location in a context coefficient register, the first location corresponding to the first scan order distance, and entropy decoding the current entropy coded transform coefficient based on the first context coefficient value. The method also includes including the entropy decoded current transform coefficient in an output bitstream.

Coding using efficient context handling in arithmetic coding is disclosed. A method for decoding a current block in a scan order includes identifying a current entropy coded transform coefficient from the current block, and entropy decoding the current entropy coded transform coefficient. Entropy decoding the current entropy coded transform coefficient may include determining, based on the scan order, a first scan order distance between a scan order location corresponding to the current entropy coded transform coefficient and a scan order location corresponding to a first context coefficient, identifying a first context coefficient value from a first location in a context coefficient register, the first location corresponding to the first scan order distance, and entropy decoding the current entropy coded transform coefficient based on the first context coefficient value. The method also includes including the entropy decoded current transform coefficient in an output bitstream.

Methods of encoding and decoding for video data are describe in which significance maps are encoded and decoded using non-spatially-uniform partitioning of the map into parts, wherein the bit positions within each part are associated with a given context. Example partition sets and processes for selecting from amongst predetermined partition sets and communicating the selection to the decoder are described.

Methods of encoding and decoding for video data are describe in which significance maps are encoded and decoded using non-spatially-uniform partitioning of the map into parts, wherein the bit positions within each part are associated with a given context. Example partition sets and processes for selecting from amongst predetermined partition sets and communicating the selection to the decoder are described.

Wavelet transformation is performed on first image data and second image data until a decomposition level becomes a decomposition level based on synthesis control data or the like, and first wavelet coefficient data and second wavelet coefficient data are thereby generated. An ROI coefficient related to an ROI and a non-ROI coefficient in the first wavelet coefficient data are determined on the basis of mask data and the ROI coefficient in the first wavelet coefficient data and a wavelet coefficient in the second wavelet coefficient data are synthesized with each other, and synthesized coefficient data are thereby generated. Inverse wavelet transformation is performed on the synthesized coefficient data until a decomposition level becomes a predetermined end level, and synthetic image data are thereby generated.

An ROI coefficient and a non-ROI coefficient in first wavelet coefficient data corresponding to a first target image are determined on the basis of mask data which is developed for the first wavelet coefficient data. The ROI coefficient in the first wavelet coefficient data and a coefficient in second wavelet coefficient data corresponding to a second target image are synthesized. Synthesized coefficient data are thereby generated. Inverse wavelet transformation is performed on the synthesized coefficient data until a decomposition level becomes a predetermined end level. Synthetic image data are thereby generated.