Example embodiments allow for training of encoders (e.g., artificial neural networks (ANNs)) to generate a color palette based on an input image. The color palette can then be used to generate, using the input image, a quantized, reduced color depth image that corresponds to the input image. Differences between a plurality of such input images and corresponding quantized images are used to train the encoder. Encoders trained in this manner are especially suited for generating color palettes used to convert images into different reduced color depth image file formats. Such an encoder also has benefits, with respect to memory use and computational time or cost, relative to the median-cut algorithm or other methods for producing reduced color depth color palettes for images.

The invention relates to a method and a device for decoding an image by means of a partition unit comprising an additional region. The method of decoding an image by means of a partition unit comprising an additional region comprises the steps of: partitioning, by reference to a syntax element acquired from a received bit stream, an encoded image, which is included in the bitstream, in at least one partition unit; define an additional region for at least one partition unit; and decoding the encoded image based on the partition unit for which the additional region is defined. The invention improves the image coding efficiency.

The invention relates to a method and a device for decoding an image by means of a partition unit comprising an additional region. The method of decoding an image by means of a partition unit comprising an additional region comprises the steps of: partitioning, by reference to a syntax element acquired from a received bit stream, an encoded image, which is included in the bitstream, in at least one partition unit; define an additional region for at least one partition unit; and decoding the encoded image based on the partition unit for which the additional region is defined. The invention improves the image coding efficiency.

A method for intra-prediction of a current block includes selecting peripheral pixels of the current block, where the peripheral pixels are used to generate a prediction block for the current block; for each prediction pixel of the prediction block, performing steps including selecting two respective pixels of the peripheral pixels; and calculating the prediction pixel by interpolating at least the two respective pixels; and coding a residual block corresponding to a difference between the current block and the prediction block.

An example device includes one or more processors, and memory storing instructions that when executed by the processors, cause the processors to receive points that represent a point cloud in three-dimensional space, and generate a data structure representing the point cloud. Generating the data structure includes encoding a position of each point in each dimension as a sequence of bits according to a tree data structure; partitioning each of the sequences into two or more portions according to a scaling depth; determining that a subset of the points is spatially isolated from a remainder of the points; quantizing each of the portions associated with the subset of the points according to a first quantization step size; quantizing each of the portions associated with the remainder of the points according to a second quantization step size; and including the quantized portions in the data structure.

An example device includes one or more processors, and memory storing instructions that when executed by the processors, cause the processors to receive points that represent a point cloud in three-dimensional space, and generate a data structure representing the point cloud. Generating the data structure includes encoding a position of each point in each dimension as a sequence of bits according to a tree data structure; partitioning each of the sequences into two or more portions according to a scaling depth; determining that a subset of the points is spatially isolated from a remainder of the points; quantizing each of the portions associated with the subset of the points according to a first quantization step size; quantizing each of the portions associated with the remainder of the points according to a second quantization step size; and including the quantized portions in the data structure.

A method and encoding unit for encoding a block of pixels into a compressed data structure determines a set of Haar coefficients for a 2×2 quad of pixels of the block of pixels, which set includes a plurality of differential coefficients and an average coefficient. A first portion of the compressed data structure is determined using the differential coefficients and includes a first set of bits which indicates an order of the magnitudes of the differential coefficients, and a second set of bits which indicates a sign and an exponent for each of one or more of the differential coefficients which are non-zero. A second portion of the compressed data structure is determined using the average coefficient determined for the 2×2 quad of pixels. The compressed data structure is stored.

A method and encoding unit for encoding a block of pixels into a compressed data structure determines a set of Haar coefficients for a 2×2 quad of pixels of the block of pixels, which set includes a plurality of differential coefficients and an average coefficient. A first portion of the compressed data structure is determined using the differential coefficients and includes a first set of bits which indicates an order of the magnitudes of the differential coefficients, and a second set of bits which indicates a sign and an exponent for each of one or more of the differential coefficients which are non-zero. A second portion of the compressed data structure is determined using the average coefficient determined for the 2×2 quad of pixels. The compressed data structure is stored.

A video decoding method, a video encoding method, related devices, and a storage medium are provided. The video decoding method includes: determining a current string to be decoded from a current coding unit of a current image; based on the current string being a unit vector string and the current string including a first pixel, determining a reference pixel of the first pixel from a historical decoding unit in the current image, the historical decoding unit being a decoded coding unit adjacent to the current coding unit in the current image, the reference pixel of the first pixel being adjacent to the first pixel in the current image; and acquiring a predicted value of the first pixel based on a reconstructed value of the reference pixel of the first pixel to obtain a decoded image. may

A video decoding method, a video encoding method, related devices, and a storage medium are provided. The video decoding method includes: determining a current string to be decoded from a current coding unit of a current image; based on the current string being a unit vector string and the current string including a first pixel, determining a reference pixel of the first pixel from a historical decoding unit in the current image, the historical decoding unit being a decoded coding unit adjacent to the current coding unit in the current image, the reference pixel of the first pixel being adjacent to the first pixel in the current image; and acquiring a predicted value of the first pixel based on a reconstructed value of the reference pixel of the first pixel to obtain a decoded image. may