Provided is an encoder including: circuitry; and memory coupled to the circuitry. In operation, the circuitry: performs a mapping process of Luma Mapping with Chroma Scaling (LMCS) for transforming a first pixel value space applied to a luma display image signal into a second pixel value space applied to a luma encoding process signal, using line segments forming a transform curve, each of which corresponds to a different one of sections obtained by partitioning the first pixel value space; and encodes an image, and in the performing of the LMCS, the circuitry determines the transform curve so that among boundary values in the second pixel value space, a first value obtained by dividing a boundary value by a base width defined according to a bit depth of the image is not equal to a second value obtained by dividing another boundary value by the base width.

An exemplary video processing method includes: receiving an omnidirectional content corresponding to a sphere; obtaining a plurality of projection faces from the omnidirectional content of the sphere according to a pyramid projection; creating at least one padding region; and generating a projection-based frame by packing the projection faces and the at least one padding region in a pyramid projection layout. The projection faces packed in the pyramid projection layout include a first projection face. The at least one padding region packed in the pyramid projection layout includes a first padding region. The first padding region connects with at least the first projection face, and forms at least a portion of one boundary of the pyramid projection layout.

An exemplary video processing method includes: receiving an omnidirectional content corresponding to a sphere; obtaining a plurality of projection faces from the omnidirectional content of the sphere according to a pyramid projection; creating at least one padding region; and generating a projection-based frame by packing the projection faces and the at least one padding region in a pyramid projection layout. The projection faces packed in the pyramid projection layout include a first projection face. The at least one padding region packed in the pyramid projection layout includes a first padding region. The first padding region connects with at least the first projection face, and forms at least a portion of one boundary of the pyramid projection layout.

A method, computer readable medium, and system are disclosed for identifying residual video data. This data describes data that is lost during a compression of original video data. For example, the original video data may be compressed and then decompressed, and this result may be compared to the original video data to determine the residual video data. This residual video data is transformed into a smaller format by means of encoding, binarizing, and compressing, and is sent to a destination. At the destination, the residual video data is transformed back into its original format and is used during the decompression of the compressed original video data to improve a quality of the decompressed original video data.

A method, computer readable medium, and system are disclosed for identifying residual video data. This data describes data that is lost during a compression of original video data. For example, the original video data may be compressed and then decompressed, and this result may be compared to the original video data to determine the residual video data. This residual video data is transformed into a smaller format by means of encoding, binarizing, and compressing, and is sent to a destination. At the destination, the residual video data is transformed back into its original format and is used during the decompression of the compressed original video data to improve a quality of the decompressed original video data.

A data compression device and a compression method are provided. The data compression device includes a quantization table processing unit and a quantization unit. The quantization table processing unit determines a target quantization table in which a quantization coefficient satisfies a data distortion rate and a compression ratio of a preset condition according to a target compression ratio. By constructing different quantization tables for different data, a distortion rate is greatly reduced based on satisfying a compression ratio, and issues that the distortion rate and the compression ratio cannot be simultaneously satisfied in the prior art are alleviated.

A data compression device and a compression method are provided. The data compression device includes a quantization table processing unit and a quantization unit. The quantization table processing unit determines a target quantization table in which a quantization coefficient satisfies a data distortion rate and a compression ratio of a preset condition according to a target compression ratio. By constructing different quantization tables for different data, a distortion rate is greatly reduced based on satisfying a compression ratio, and issues that the distortion rate and the compression ratio cannot be simultaneously satisfied in the prior art are alleviated.

Display with an appropriate luminance dynamic range is realizable on a receiving side. A gamma curve is applied to input video data having a level range from 0% to 100%*N (N: a number larger than 1) to obtain transmission video data. This transmission video data is transmitted together with auxiliary information used for converting a high-luminance level on the receiving side. A high-level side level range of the transmission video data is converted on the receiving side such that a maximum level becomes a predetermined level based on the auxiliary information received together with the transmission video data.

Display with an appropriate luminance dynamic range is realizable on a receiving side. A gamma curve is applied to input video data having a level range from 0% to 100%*N (N: a number larger than 1) to obtain transmission video data. This transmission video data is transmitted together with auxiliary information used for converting a high-luminance level on the receiving side. A high-level side level range of the transmission video data is converted on the receiving side such that a maximum level becomes a predetermined level based on the auxiliary information received together with the transmission video data.

The present embodiments obtain chroma components representative of the chroma components of an output image from color components representative of an input image, and if a value of a pixel in at least one of said chroma components exceeds a given value, modify the value of said pixel in at least one of said color components in such a way that the value of said pixel in said at least one of said chroma components is lower than or equals to said given value.