A video decoder, encoder, and corresponding methods for processing video data for an image block and a particular reference picture index to predict the image block are disclosed that utilize adaptive weighting of reference pictures to enhance video compression, where a decoder includes a reference picture weighting factor unit for determining a weighting factor corresponding to the particular reference picture index; an encoder includes a reference picture weighting factor assignor for assigning a weighting factor corresponding to the particular reference picture index; and a method for decoding includes receiving a reference picture index with the data that corresponds to the image block, determining a weighting factor for each received reference picture index, retrieving a reference picture for each index, motion compensating the retrieved reference picture, and multiplying the motion compensated reference picture by the corresponding weighting factor to form a weighted motion compensated reference picture.

A video decoder, encoder, and corresponding methods for processing video data for an image block and a particular reference picture index to predict the image block are disclosed that utilize adaptive weighting of reference pictures to enhance video compression, where a decoder includes a reference picture weighting factor unit for determining a weighting factor corresponding to the particular reference picture index; an encoder includes a reference picture weighting factor assignor for assigning a weighting factor corresponding to the particular reference picture index; and a method for decoding includes receiving a reference picture index with the data that corresponds to the image block, determining a weighting factor for each received reference picture index, retrieving a reference picture for each index, motion compensating the retrieved reference picture, and multiplying the motion compensated reference picture by the corresponding weighting factor to form a weighted motion compensated reference picture.

An image coding apparatus, including an encoder and a memory, and an image coding method are provided. In the image coding apparatus, the encoder executes operations, including obtaining a reference-specific image from storage accessible by the encoder, the reference-specific image being referenced from one or more other images to be displayed, and storing the reference-specific image in the memory. The operations further include encoding one or more to-be-displayed images by referring to the reference-specific image, wherein the obtained reference-specific image is formed by integrating a plurality of images. An image decoding apparatus and an image decoding method are also provided.

An image coding apparatus, including an encoder and a memory, and an image coding method are provided. In the image coding apparatus, the encoder executes operations, including obtaining a reference-specific image from storage accessible by the encoder, the reference-specific image being referenced from one or more other images to be displayed, and storing the reference-specific image in the memory. The operations further include encoding one or more to-be-displayed images by referring to the reference-specific image, wherein the obtained reference-specific image is formed by integrating a plurality of images. An image decoding apparatus and an image decoding method are also provided.

Particular embodiments provide a variable, BitDepth, that may be set at a value based on a number of bits used to represent pixels in pictures of a video. The variable may be used in syntax elements in HEVC, such as the HEVC range extension, but other coding standards may be used. By using the variable, different resolutions for the video may be accommodated during the encoding and decoding process. For example, the number of pixels in the pictures may be represented by 8 bits, 10 bits, 12 bits, or another number of bits depending on the resolution. Using the BitDepth variable in the syntax provides flexibility in the motion estimation and motion compensation process. For example, syntax elements used in the weighted prediction process may take into account different numbers of bits used to represent the pictures.

The present disclosure relates to motion vector refinement. As a first step, an initial motion vector and a template for the block are obtained. Then, the refinement of the initial motion vector is determined by template matching with said template in a search space. The search space is located on a position given by the initial motion vector and includes one or more fractional sample positions, wherein each of the fractional sample positions belonging to the search space is obtained by interpolation filtering with a filter of a predefined tap-size assessing integer samples only within a window, said window being formed by integer samples accessible for the template matching in said search space.

Particular embodiments may remove a condition check in the semantics for checking a high-precision data flag. This simplifies the semantics used in the encoding and decoding process. In this case, even if the high-precision data flag is not set, the value of the weighted prediction syntax element is set by the BitDepth variable. However, even if the BitDepth is not considered high-precision data, such as 8 bits, the range for the weighted prediction syntax element is still the same as the fixed value. For example, the syntax elements luma_offset_l0[i], luma_offset_l1[i], delta_chroma_offset_l0[i][j], and delta_chroma_offset_l1[i][j] use the variable BitDepth as described above whether the flag extended_precision_processing_flag is enabled and not enabled to indicate whether the bit depth is above a threshold.

Particular embodiments may remove a condition check in the semantics for checking a high-precision data flag. This simplifies the semantics used in the encoding and decoding process. In this case, even if the high-precision data flag is not set, the value of the weighted prediction syntax element is set by the BitDepth variable. However, even if the BitDepth is not considered high-precision data, such as 8 bits, the range for the weighted prediction syntax element is still the same as the fixed value. For example, the syntax elements luma_offset_l0[i], luma_offset_l1[i], delta_chroma_offset_l0[i][j], and delta_chroma_offset_l1[i][j] use the variable BitDepth as described above whether the flag extended_precision_processing_flag is enabled and not enabled to indicate whether the bit depth is above a threshold.

Obtaining one or more motion vector predictor candidates includes: (a1) generating a motion vector predictor candidate, based on motion vectors of first adjacent blocks adjacent to a block to be processed in a first direction; and (a2) generating a motion vector predictor candidate, based on motion vectors of second adjacent blocks adjacent to the block to be processed in a second direction, and step (a2) includes: determining whether the first adjacent blocks include an inter-predicted block; and searching for a motion vector on which scaling processing can be performed from among the motion vectors of the second adjacent blocks when it is determined that the first adjacent blocks do not include an inter-predicted block, and executing, when the motion vector on which scaling processing can be performed is obtained in the search, scaling processing on the motion vector obtained in the search.

Obtaining one or more motion vector predictor candidates includes: (a1) generating a motion vector predictor candidate, based on motion vectors of first adjacent blocks adjacent to a block to be processed in a first direction; and (a2) generating a motion vector predictor candidate, based on motion vectors of second adjacent blocks adjacent to the block to be processed in a second direction, and step (a2) includes: determining whether the first adjacent blocks include an inter-predicted block; and searching for a motion vector on which scaling processing can be performed from among the motion vectors of the second adjacent blocks when it is determined that the first adjacent blocks do not include an inter-predicted block, and executing, when the motion vector on which scaling processing can be performed is obtained in the search, scaling processing on the motion vector obtained in the search.