Disclosed herein are a QTBT split structure allowing blocks of various shapes capable of more efficiently reflecting various local characteristics of video and a method of efficiently signaling the split structure.

An image encoding/decoding method and apparatus are provided. An image decoding method performed by an image decoding apparatus may comprise identifying a current chroma block by splitting an image, identifying whether a matrix based intra prediction mode applies to a first luma sample position corresponding to the current chroma block, identifying whether a predetermined prediction mode applies to a second luma sample position corresponding to the current chroma block, based on the matrix based intra prediction mode doing not apply, and determining an intra prediction mode candidate of the current chroma block based on an intra prediction mode applying to a third luma sample position corresponding to the current chroma block, based on the predetermined prediction mode doing not apply.

An image encoding/decoding method and apparatus are provided. An image decoding method performed by an image decoding apparatus may comprise identifying a current chroma block by splitting an image, identifying whether a matrix based intra prediction mode applies to a first luma sample position corresponding to the current chroma block, identifying whether a predetermined prediction mode applies to a second luma sample position corresponding to the current chroma block, based on the matrix based intra prediction mode doing not apply, and determining an intra prediction mode candidate of the current chroma block based on an intra prediction mode applying to a third luma sample position corresponding to the current chroma block, based on the predetermined prediction mode doing not apply.

A video encoding method and apparatus and a video decoding method and apparatus are provided. The video encoding method includes: prediction encoding in units of a coding unit as a data unit for encoding a picture, by using partitions determined based on a first partition mode and a partition level, so as to select a partition for outputting an encoding result from among the determined partitions; and encoding and outputting partition information representing a first partition mode and a partition level of the selected partition. The first partition mode represents a shape and directionality of a partition as a data unit for performing the prediction encoding on the coding unit, and the partition level represents a degree to which the coding unit is split into partitions for detailed motion prediction.

A video encoding method and apparatus and a video decoding method and apparatus are provided. The video encoding method includes: prediction encoding in units of a coding unit as a data unit for encoding a picture, by using partitions determined based on a first partition mode and a partition level, so as to select a partition for outputting an encoding result from among the determined partitions; and encoding and outputting partition information representing a first partition mode and a partition level of the selected partition. The first partition mode represents a shape and directionality of a partition as a data unit for performing the prediction encoding on the coding unit, and the partition level represents a degree to which the coding unit is split into partitions for detailed motion prediction.

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.

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.

According to the present invention, an image encoding apparatus comprises: a motion prediction unit which derives motion information on a current block in the form of the motion information including L0 motion information and L1 motion information; a motion compensation unit which performs a motion compensation for the current block on the basis of at least one of the L0 motion information and L1 motion information so as to generate a prediction block corresponding to the current block; and a restoration block generating unit which generates a restoration block corresponding to the current block based on the prediction block. According to the present invention, image encoding efficiency can be improved.

The present disclosure relates to an image processing device and an image processing method for generating a celestial sphere image such that the pixels near the poles of the sphere are kept from increasing in density when the image is mapped to the sphere surface.

An encoder encodes, with respect to an omnidirectional image generated by equidistant cylindrical projection to include a top image, a middle image, and a bottom image in a vertical direction, the middle image into an encoded stream at a high resolution, and the top image and the bottom image into encoded streams at a resolution lower than the high resolution. This disclosure is applicable to image display systems, among others.

A method for encoding a video signal includes estimating a space requirement for encoding a tile of a video frame, writing a first value in a first value space of the bitstream, wherein the first value describes a size of a second value space, and defining the second value space in the bitstream, wherein the size of the second value space is based on an estimated space requirement. The method also includes writing encoded content in a content space of the bitstream, determining a size of the content space subsequent to writing encoded content in the content space, and writing a second value in the second value space of the bitstream, wherein the second value describes the size of the content space.