Mitsubishi Electric Research Laboratories, Inc.

Robert Cohen

Anthony Vetro

Shantanu Rane

Huifang Sun

Dong Tian

Jewon Kang

Osman G Sezer

Kazuo Sugimoto

Guoxin Jin

Eduardo Pavez

Xiaozhong Xu

A point cloud encoder including an input interface to accept a dynamic point cloud including a sequence of point cloud frames of a scene. A processor encodes blocks of a current point cloud frame to produce an encoded frame. Wherein, for encoding a current block of the current point cloud frame, a reference block is selected similar to the current block according to a similarity metric to serve as a reference to encode the current block. Pair each point in the current block to a point in the reference block based on values of the paired points. Encode the current block based on a combination of an identification of the reference block and residuals between the values of the paired points. Wherein the residuals are ordered according to an order of the values of the points in the reference block. A transmitter transmits the encoded frame over a communication channel.

System and method for inter-frame predictive compression for point clouds

In a decoder, a desired image is estimated by first retrieving coding modes from an encoded side information image. For each bitplane in the encoded side information image, syndrome bits or parity bits are decoded to obtain an estimated bitplane of quantized transform coefficients of the desired image. A quantization and a transform are applied to a prediction residual obtained using the coding modes, wherein the decoding uses the quantized transform coefficients of the encoded side information image, and is based on previously decoded bitplanes in a causal neighborhood. The estimated bitplanes of quantized transform coefficients of the desired image are combined to produce combined bitplanes. Then, an inverse quantization, an inverse transform and a prediction based on the coding modes are applied to the combined bitplanes to recover the estimate of the desired image.

Method for improving compression efficiency of distributed source coding using intra-band information

Blocks in pixel images are template matched to select candidate blocks and weights according to a structural similarity and a perceptual distortion of the blocks. The perceptual distortion is a function of a just-noticeable-distortion (JND). A filter outputs a prediction residual between the block and the candidate blocks. The prediction residual is transformed and quantized to produce a quantized prediction residual using the JND. The matching and quantizing is optimized jointly using the perceptual distortion. Then, the quantized prediction residual and the weights are entropy encoded into a bit-stream for later decoding.

Perceptually coding images and videos

In a decoder, a desired image is estimated by first retrieving coding modes from an encoded side information image. For each bitplane in the encoded side information image, syndrome bits or parity bits are decoded to obtain an estimated bitplane of quantized transform coefficients of the desired image. A quantization and a transform are applied to a prediction residual obtained using the coding modes, wherein the decoding uses the quantized transform coefficients of the encoded side information image. The estimated bitplanes of quantized transform coefficients of the desired image are combined to produce combined bitplanes. Then, an inverse quantization, an inverse transform and a prediction based on the coding modes are applied to the combined bitplanes to recover the estimate of the desired image.

Distributed source coding using prediction modes obtained from side information

A method codes pictures in a bitstream, wherein the bitstream includes coded pictures to obtain data for associated TUs and data for generating a transform tree, and a partitioning of coding units (CUs) into Prediction Units (PUs), and data for obtaining prediction modes or directions associated with each PU. One or more mapping tables are defined, wherein each row of each table has an associated index and a first set of transform types to be used for applying an inverse transformation to the data in TU. The first set of transform types is selected according to an index, and then a second set of transform types is applied as the inverse transformation to the data, wherein the second set of transform types is determined according to the first set of transform types and a transform-toggle flag (ttf) to obtain a reconstructed prediction residual.

Method for selecting transform types from mapping table for prediction modes

A system and a method for decoding at least a portion of an image includes determining a current prediction mode based on a combination of a prediction mode residue and a function of at least one previous prediction mode and decoding the portion of the image using the current prediction mode.

Coding images using intra prediction modes

A video encoded as a bit stream is decoded by maintaining a set of dictionaries generated from decoded prediction residual signals, wherein elements of the set of dictionaries have associated indices. A current macroblock is entropy decoded and inverse quantized to produce decoded coefficients. For the current macroblock, a particular dictionary of the set of dictionaries is selected according to a prediction mode signaled in the bit stream, and particular elements of the particular dictionary are selected according to a copy mode signal in the bit stream and the associated index. The particular elements is scaled and combined, using the decoded coefficients, to reconstruct a current decoded macroblock prediction residual signal. Then, the current decoded macroblock prediction residual signal is combined with previously decoded macroblocks to generate an output macroblock of a reconstructed video, wherein the steps are performed in a decoder.

Method for coding videos using dictionaries

A bitstream includes coded pictures, and split-flags for generating a transform tree. The bit stream is a partitioning of coding units (CUs) into Prediction Units (PUs). The transform tree is generated according to the split-flags. Nodes in the transform tree represent transform units (TU) associated with the CUs. The generation splits each TU only if the corresponding split-flag is set. For each PU that includes multiple TUs, the multiple TUs are merged into a larger TU, and the transform tree is modified according to the splitting and merging. Then, data contained in each PU can be decoded using the TVs associated with the PU according to the transform tree.

Method for coding pictures using hierarchical transform units

A video encoded as a bit stream is decoded using trained sparse orthonormal transforms generated from decoded prediction residual signals, wherein the transforms have associated indices. A current macroblock is entropy decoded and inverse quantized to produce decoded coefficients. For the current macroblock, an L-norm regularized training process generates a set of mode-dependent sparse orthonormal inverse transforms, selected according to a prediction mode signaled in the bit stream. Decoded coefficients are inverse transformed and then are combined with previously decoded macroblocks to generate an output macroblock of a reconstructed video.

Method for training and utilizing separable transforms for video coding

A bitstream includes coded pictures, and split-flags for generating a transform tree. The bit stream is a partitioning of coding units (CUs) into Prediction Units (PUs). The transform tree is generated according to the split-flags. Nodes in the transform tree represent transform units (TU) associated with the CUs. The generation splits each TU only if the corresponding split-flag is set. For each PU that includes multiple TUs, the multiple TUs are merged into a larger TU, and the transform tree is modified according to the splitting and merging. Then, data contained in each PU can be decoded using the TUs associated with the PU according to the transform tree.

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Somerville, MA, United States of America

Robert Cohen