A three-dimensional data encoding method includes: obtaining an attribute information item of a three-dimensional point; executing an encoding process that executes a transform process on a numerical value indicated by the attribute information item and encodes the attribute information item or that encodes the attribute information item without executing the transform process, the transform process performing at least one of scaling or offset, the scaling performing at least one of a multiplication and division operation or a shift operation, the offset performing an addition and subtraction operation; and generating a bitstream including the attribute information item encoded and a transform identification information item indicating whether the transform process has been executed.

An image encoding device includes a prediction unit configured to generate prediction errors being a difference between a predicted image obtained by prediction processing for an input image and the input image, a first transform unit configured to generate first transform coefficients by performing orthogonal transform on the prediction errors, a second transform unit configured to generate second transform coefficients by performing LFNST processing on the first transform coefficients, a quantization unit configured to generate quantization coefficients by performing quantization processing on the second transform coefficients, and an encoding unit configured to encode the quantization coefficients, wherein the encoding unit encodes information indicating whether a range of possible values at least taken by the second transform coefficients is to be a range determined based on a bit depth or a fixed range.

An image encoding device includes a prediction unit configured to generate prediction errors being a difference between a predicted image obtained by prediction processing for an input image and the input image, a first transform unit configured to generate first transform coefficients by performing orthogonal transform on the prediction errors, a second transform unit configured to generate second transform coefficients by performing LFNST processing on the first transform coefficients, a quantization unit configured to generate quantization coefficients by performing quantization processing on the second transform coefficients, and an encoding unit configured to encode the quantization coefficients, wherein the encoding unit encodes information indicating whether a range of possible values at least taken by the second transform coefficients is to be a range determined based on a bit depth or a fixed range.

Techniques for coding and deriving (e.g., determining) one or more coded-block-flags associated with video content are described herein. A coded-block-flag of a last node may be determined when coded-block-flags of preceding nodes are determined to be a particular value and when a predetermined condition is satisfied. In some instances, the predetermined condition may be satisfied when log.sub.2(size of current transform unit) is less than log.sub.2(size of maximum transform unit) or log.sub.2(size of current coding unit) is less than or equal to log.sub.2(size of maximum transform unit)+1. The preceding nodes may be nodes that precede the last node on a particular level in a residual tree.

Techniques for coding and deriving (e.g., determining) one or more coded-block-flags associated with video content are described herein. A coded-block-flag of a last node may be determined when coded-block-flags of preceding nodes are determined to be a particular value and when a predetermined condition is satisfied. In some instances, the predetermined condition may be satisfied when log.sub.2(size of current transform unit) is less than log.sub.2(size of maximum transform unit) or log.sub.2(size of current coding unit) is less than or equal to log.sub.2(size of maximum transform unit)+1. The preceding nodes may be nodes that precede the last node on a particular level in a residual tree.

Techniques for lossless compression of a digital image using prior image context.

Techniques for lossless compression of a digital image using prior image context.

A method of encoding video data values, the method including selectively encoding, via circuitry, a high bit depth control flag and, when the high bit depth control flag is set to indicate high bit depth operation, selectively encoding an extended precision flag to indicate at least extended precision operation of a spatial frequency transform stage and encoding the video data values according to a mode of operation defined by the encoded high bit depth control flag and, when encoded, the extended precision flag.

A feature data encoding method, an encoder, a feature data decoding method, and a decoder are provided. The feature data encoding method includes following steps. A transform unit is divided into a plurality of sub-blocks and N sub-transform units. A reference origin and a LSC are determined in an i-th sub-transform unit of the sub-transform units, and an original coordinate of the last significant coefficient of the i-th sub-transform unit is modified to a specific coordinate. The i-th sub-transform unit is scanned from a specific sub-block of the i-th sub-transform unit, and significant feature coefficients in the i-th sub-transform unit are individually encoded as coded data.

A feature data encoding method, an encoder, a feature data decoding method, and a decoder are provided. The feature data encoding method includes following steps. A transform unit is divided into a plurality of sub-blocks and N sub-transform units. A reference origin and a LSC are determined in an i-th sub-transform unit of the sub-transform units, and an original coordinate of the last significant coefficient of the i-th sub-transform unit is modified to a specific coordinate. The i-th sub-transform unit is scanned from a specific sub-block of the i-th sub-transform unit, and significant feature coefficients in the i-th sub-transform unit are individually encoded as coded data.