The present disclosure provides a video data processing method. The method includes receiving a bitstream; decoding an index associated with a coding unit based on the bitstream, the index indicating a selection mode among at least four selection modes; determining four samples based on the index; determining two parameters based on the four samples; determining predicted samples of the coding unit based on the two parameters; and decoding the coding unit based on the predicted samples.

A method, computer program, and computer system is encoding or decoding video data. Video data may include a syntax element indicating a quantization index, wherein a range of the quantization index is extended by an offset value. The syntax element may be parsed to determine the quantization index, a quantization step size may be obtained from a lookup table based on the quantization index and the offset value; and the video data may be encoded or decoded based on the quantization step size.

A method, computer program, and computer system is encoding or decoding video data. Video data may include a syntax element indicating a quantization index, wherein a range of the quantization index is extended by an offset value. The syntax element may be parsed to determine the quantization index, a quantization step size may be obtained from a lookup table based on the quantization index and the offset value; and the video data may be encoded or decoded based on the quantization step size.

Disclosed is an image compression method of a digital pathology system. The image compression method is a method of compressing digital slide images having first to nth original plane images (n is a natural number greater than or equal to 2). The image compression method includes selecting a block having an optimal focal point as an optimal block from each set of blocks positioned at identical positions of the first to nth original plane images; forming one plane image as a virtual optimal plane image by combining only the optimal blocks; generating block descriptors for forming the first to nth original plane images based on the virtual optimal plane image; generating first to nth predictive plane images from the virtual optimal plane image such that the first to nth predictive plane images are the least out of focus by using location information for the blocks and the block descriptors; generating first to nth differential plane images, the first differential plane image corresponding to a difference between the first original plane image and the first predictive plane image and the nth differential plane image corresponding to a difference between the nth original plane image and the nth predictive plane image; and compressing the first to nth differential plane images.

A video encoding method includes deriving entry point information specifying an entry point of a substream for a picture. The entry point information may include a number syntax element representing a number of offset syntax elements in a slice header; an offset syntax element representing an entry point offset between in bytes two entry points; and a length syntax element representing a bits length of the offset syntax element. A value of the length syntax element plus one corresponds to the bits length of the offset syntax element and the length syntax element is signaled when the number of the offset syntax elements is larger than 0. A value of the number syntax element corresponds to the number of offset syntax elements in the slice header, and the offset syntax element is signaled when the number of the offset syntax elements is larger than 0.

A video encoding method includes deriving entry point information specifying an entry point of a substream for a picture. The entry point information may include a number syntax element representing a number of offset syntax elements in a slice header; an offset syntax element representing an entry point offset between in bytes two entry points; and a length syntax element representing a bits length of the offset syntax element. A value of the length syntax element plus one corresponds to the bits length of the offset syntax element and the length syntax element is signaled when the number of the offset syntax elements is larger than 0. A value of the number syntax element corresponds to the number of offset syntax elements in the slice header, and the offset syntax element is signaled when the number of the offset syntax elements is larger than 0.

To increase efficiency of a bit-depth scalable data-stream an inter-layer prediction is obtained by mapping samples of the representation of the picture or video source data with a first picture sample bit-depth from a first dynamic range corresponding to the first picture sample bit-depth to a second dynamic range greater than the first dynamic range and corresponding to a second picture sample bit-depth being higher than the first picture sample bit-depth by use of one or more global mapping functions being constant within the picture or video source data or varying at a first granularity, and a local mapping function locally modifying the one or more global mapping functions and varying at a second granularity smaller than the first granularity, with forming the quality-scalable data-stream based on the local mapping function such that the local mapping function is derivable from the quality-scalable data-stream.

To increase efficiency of a bit-depth scalable data-stream an inter-layer prediction is obtained by mapping samples of the representation of the picture or video source data with a first picture sample bit-depth from a first dynamic range corresponding to the first picture sample bit-depth to a second dynamic range greater than the first dynamic range and corresponding to a second picture sample bit-depth being higher than the first picture sample bit-depth by use of one or more global mapping functions being constant within the picture or video source data or varying at a first granularity, and a local mapping function locally modifying the one or more global mapping functions and varying at a second granularity smaller than the first granularity, with forming the quality-scalable data-stream based on the local mapping function such that the local mapping function is derivable from the quality-scalable data-stream.

Techniques and tools for reducing latency in video encoding and decoding by constraining latency due to reordering of video frames, and by indicating the constraint on frame reordering latency with one or more syntax elements that accompany encoded data for the video frames. For example, a real-time communication tool with a video encoder sets a syntax element that indicates a constraint on frame reordering latency, which is consistent with inter-frame dependencies between multiple frames of a video sequence, then outputs the syntax element. A corresponding real-time communication tool with a video decoder receives the syntax element that indicates the constraint on frame reordering latency, determines the constraint on frame reordering latency based on the syntax element, and uses the constraint on frame reordering latency to determine when a reconstructed frame is ready for output (in terms of output order).

Techniques and tools for reducing latency in video encoding and decoding by constraining latency due to reordering of video frames, and by indicating the constraint on frame reordering latency with one or more syntax elements that accompany encoded data for the video frames. For example, a real-time communication tool with a video encoder sets a syntax element that indicates a constraint on frame reordering latency, which is consistent with inter-frame dependencies between multiple frames of a video sequence, then outputs the syntax element. A corresponding real-time communication tool with a video decoder receives the syntax element that indicates the constraint on frame reordering latency, determines the constraint on frame reordering latency based on the syntax element, and uses the constraint on frame reordering latency to determine when a reconstructed frame is ready for output (in terms of output order).