993 results about "Rate distortion" patented technology

Motion estimation of a macro block in inter16×16, inter16×8, and inter8×16 modes is performed and a determination of whether to further perform motion estimation in a P8×8 mode is made. Motion estimation in P8×8 mode is either omitted or performed and one mode is determined according to a rate distortion cost of the respective modes. Spatial prediction encoding may then be performed or omitted based on comparing the rate distortion cost of the one mode with a predetermined value. Accordingly, by selectively omitting variable block motion estimation and spatial prediction encoding which are the most complicated operations in an H.264 encoder, determining an encoding mode is rapidly performed such that encoding speed increases.

A better rate distortion ratio is achieved by making interrelationships between coding parameters of different planes available for exploitation for the aim of redundancy reduction despite the additional overhead resulting from the need to signal the inter-plane prediction information to the decoder. In particular, the decision to use inter plane prediction or not may be performed for a plurality of planes individually. Additionally or alternatively, the decision may be done on a block basis considering one secondary plane.

Provided is an apparatus and method for encoding and decoding using alternative transform units according to the correlation of residual signals. The video encoding apparatus includes a first transforming unit for performing discrete cosine transform (DCT), first quantization, first inverse quantization, and inverse DCT on a block basis onto residual coefficients generated after intra frame prediction or inter frame prediction; a second transforming unit for performing discrete sine transform (DST), second quantization, second inverse quantization, and inverse DST on a block basis onto the residual coefficients; a selecting unit for selecting one having a high compression rate between the first and second transforming units for each block through performing rate-distortion optimization; and a flag marking unit for recording information about the selected transforming unit at a flag bit provided on a macroblock basis.

Method, video encoders, and digital systems are provide in which motion vector determination includes selecting a plurality of candidate motion vectors for a macroblock using a cost function including both a block distortion measure and a motion vector cost measure for single-partition motion vectors in the plurality of candidate motion vectors and using a cost function including a distortion measure without a motion vector cost measure for multi-partition motion vectors in the plurality of candidate motion vectors, and refining the plurality of candidate motion vectors to obtain a refined plurality of candidate motion vectors, wherein multi-partition motion vectors of the plurality of candidate motion vectors are refined using a cost function including a distortion measure without a motion vector cost measure and single-partition motion vectors of the plurality of candidate motion vectors are refined using a cost function including both a block distortion measure and a motion vector cost measure.

A fast video encoder (100) and method (500) for selecting (809) Inter macro-block mode or intra macro-block mode is provided. The method can include estimating (502) a rate-distortion cost (801) of a plurality of predictors (203) for coding a video (201), selecting (504) a predictive coding mode for the video based on a minimization of the rate-distortion cost, and coding (505) the image using a predictive mode associated with the minimum rate-distortion cost. The rate-distortion cost can be estimated across Intra macro-block modes and Inter macro-block modes for reducing a computational complexity. Rate-Distortion costs can be terminated early (524) based on statistical information (522) across a plurality of predictors for increasing an encoding speed. A fast estimation of the rate-distortion cost associated with the Intra macro-block mode for making inter/intra macro-block mode decision in a video coding system by exploiting the coding statistics across prediction modes is presented.

A method and a device are described for selecting between multiple available filters in an encoder to provide a frame having a low error and distortion rate. For each full and sub pixel position, determining whether to use an alternative filter over the default filter during interpolation by estimating the rate distortion gain of using each filter and signaling to the decoder the optimal filter(s) applied to each full and sub-pixel position. In one embodiment, identifying a reference frame and a current frame, interpolating the reference frame using a default filter to create a default interpolated frame, interpolating the reference frame using an alternative filter to create an alternative interpolated frame, determining for each sub-pixel position whether to use the default filter or the alternative filter based on a minimal cost to generate a final reference frame.

Methods for motion estimation with adaptive motion accuracy of the present invention include several techniques for computing motion vectors of high pixel accuracy with a minor increase in computation. One technique uses fast-search strategies in sub-pixel space that smartly searches for the best motion vectors. An alternate technique estimates high-accurate motion vectors using different interpolation filters at different stages in order to reduce computational complexity. Yet another technique uses rate-distortion criteria that adapts according to the different motion accuracies to determine both the best motion vectors and the best motion accuracies. Still another technique uses a VLC table that is interpreted differently at different coding units, according to the associated motion vector accuracy.

The invention discloses a self-adaption dividing method for code units in high-efficiency video coding, which mainly solves the problems that a largest code unit and a smallest code unit in the division of the code units in the prior art can not be regulated according to the characteristics of video content, and the dividing mode quantity of blocks on the boundary of a video frame is few. The method comprises the steps of: firstly, adopting the rate distortion rule or the relativity among video frames to self-adaptively determine the largest code unit and the smallest code unit in each video frame; secondly, expanding a rectangular block within the video frame in the largest code unit on the boundary of a video frame into a square block, and dividing the square block; then, marking the rectangular blocks after dividing, and carrying out frame prediction to the rectangular blocks after dividing; and finally, transforming, quantizing and entropy coding to prediction residuals. The invention has the advantage of high video compression efficiency, and can be applied to high-performance video coding standards.

A method and apparatus for processing in-loop reconstructed video using an in-loop filter is disclosed. In the recent HEVC development, adaptive loop filtering (ALF) is being adopted to process in-loop reconstruction video data, where ALF can be selectively turned ON or OFF for each block in a frame or a slice. An advanced ALF is disclosed later that allows a choice of multiple filter sets that can be applied to the reconstructed video data adaptively. In the present disclosure, pixels of the in-loop reconstructed video data are divided into a plurality of to-be-filtered regions, and an in-loop filter from a filter set is determined for each to-be-filtered region based on a rate-distortion optimization procedure. According to one embodiment of the present invention, computation of cost function associated with the rate-distortion optimization procedure is related to correlation values associated with original video data and the in-loop reconstructed video data. Furthermore, the correlation values can be shared by the multiple candidate filters during the rate-distortion optimization procedure for said each to-be-filtered region. In another embodiment, the correlation values can be shared by multiple candidate to-be-filtered regions of an area of the in-loop reconstructed video data during the rate-distortion optimization procedure for the area of the in-loop reconstructed video data.

An MPEG-4 system with error concealment is provided for video service under the network with packet loss. The MPEG-4 system includes an encoder and a decoder. The encoder uses an intra-refreshment technique is used to make coded bitstream more robust against noise in order to stop error propagation. The rate-distortion optimization criterion is also introduced to adaptively update in synchronization with intra-coded blocks adaptively based on the true network condition with minimal overhead. The Lagrange multiplier is modified to achieve the best rate-distortion balance. In addition, a decoder loop is used in the encoder and is synchronized with the true decoder to achieve the best performance and avoid mismatch with the decoder used in the MPEG-4 system. The decoder is able to achieve resilient decoding from any kind of noise and enhance the reconstructed image quality with spatial and temporal hybrid concealment method. The result shows that a 3.65-9.71 dB further improvement on peak-signal-to-noise-ratio (PSNR) can be achieved in comparison with the existing methods that adopt spatial copy and zero motion concealment in decoding.

With adaptive multiple quantization, a video or other digital media codec can adaptively select among multiple quantizers to apply to transform coefficients based on content or bit rate constraints, so as to improve quality through rate-distortion optimization. The switch in quantizers can be signaled at the sequence level or frame level of the bitstream syntax, or can be implicitly specified in the syntax.

There is disclosed a system and method for video coding, and more particularly to video coding that uses structural similarity (SSIM) based rate-distortion optimization methods to improve the perceptual quality of decoded video without increasing data rate, or to reduce the data rate of compressed video stream without sacrificing perceived quality of the decoded video. In an embodiment, the video coding system and method may be a SSIM-based rate-distortion optimization approach that involves minimizing a joint cost function defined as the sum of a data rate term and a distortion functions. The distortion function may be defined to be monotonically increasing with the decrease of SSIM and a Lagrange parameter may be utilized to control the trade-off between rate and distortion. The optimal Lagrange parameter may be found by utilizing the ratio between a reduced-reference SSIM model with respect to quantization step, and a data rate model with respect to quantization step. In an embodiment, a group-of-picture (GOP) level quantization parameter (QP) adjustment method may be used in multi-pass encoding to reduce the bit-rate while keeping similar perceptual video quality. In another embodiment, a frame level QP adjustment method may be used in single-pass encoding to achieve constant SSIM quality. In accordance with an embodiment, the present invention may be implemented entirely at the encoder side and may or may not require any change at the decoder, and may be made compatible with existing video coding standards.

An inter-mode for encoding a video macroblock is selected based on a comparison of at least two rate-distortion values associated with inter-modes. The number of potential inter-modes for encoding the video macroblock is initially reduced based on the rate-distortion calculation of the SKIP mode between the current macroblock and the collocated macroblock (corresponding to a 0,0 motion vector). Motion estimation is performed on the remaining inter-modes to identify reference blocks and motion vectors. The number of calculations performed in identifying the reference blocks and motion vectors is potentially reduced because associations between inter-modes are recognized and leveraged.

A system and method are disclosed that provide a simple and efficient layered video coding technique using a backward adaptive rate-distortion optimized data partitioning (RD-DP) of DCT coefficients. The video coding system may include an rate-distortion optimized data partitioning encoder and decoder. The RD-DP encoder adapts the partition point block-by-block which greatly improves the coding efficiency of the base layer bit stream without explicit transmission thereby saving the bandwidth significantly. The RD-DP decoder can also find the partition location in backward-fashion from the decoded data.

The embodiments of the present invention provide a method and a device for encoding and decoding videos, and relate to the communication field, and an efficient transformation matrix corresponding to features of each residual block is selected for transformation, which therefore improves encoding efficiency. The solution provided in an embodiment of the present invention is: generating a prediction residual according to input video data; selecting a set of best transformation matrixes among multiple candidate transformation matrixes according to an intra-frame prediction mode and rate-distortion criteria to perform transform-coding on the prediction residual and obtain a transformation result; and generating an encoded stream according to the transformation result and selected transformation matrix index information.

A system and method provide a video coding system for adaptively transcoding videos based on video coding complexity (VCC). A VCC engine of the system is configured to generate a measure of how difficult to encode a source video based on a trained VCC model. A video rate-distortion modeling engine of the system is configured to estimate a rate-distortion model and a scaling model. The VCC model, rate-distortion model and the scaling model are trained on a video corpus of the system. The trained VCC model, rate-distortion model and the scaling model are used by an adaptive bitrate transcoding sub-system to transcode a source video with an optimized bitrate and visual quality. The trained VCC model, rate-distortion model and the scaling model are further used by an adaptive resolution transcoding sub-system to transcode a source video with an optimized resolution and visual quality.

The present invention includes a method and system for image compression using block size heuristics. A method for motion searching a video frame is disclosed including iteratively decreasing block size until a rate-distortion (RD) has been minimized. A method for compressing motion video images is disclosed. Additionally, a system for transmitting and receiving video images is disclosed. The system may be a video conferencing system.

The invention relates to an intra-frame prediction method, comprising the following steps that: a 4x4 pixel luma block to be predicted is chosen to be as a current block; whether the current block is the center block is judged, if yes, energy functions of the residual error between prediction blocks of the current block and the current block in all predicting modes and a candidate predicting mode is determined according to the energy functions in different predicting modes, otherwise, a usable predicting mode is taken as the candidate predicting mode; a rate-distortion cost parameter in the candidate predicting mode is calculated, the candidate predicting mode with the minimal rate-distortion cost parameter is taken as the optimal predicting mode of the current block. The invention determines the candidate predicting mode according to the residual error energy function and determines the optimal predicting mode by calculating the rate-distortion cost parameter of the candidate predicting mode so as to decrease the number of the predicting modes which need to calculate the rate-distortion cost parameter, thereby reducing the amount of computation.

The invention provides a screen image compression device and a compression method thereof. A plurality of sets of complemental coding tool combinations are used by the compression device, a coding unit with a certain pixel is taken as a coding unit, to a same coding unit, a plurality of sets of coding tool combinations are used simultaneously to carry out precoding, and a combination with an optimal rate-distortion characteristic is selected to compress the coding unit. Simultaneously, the invention provides a decompression apparatus and a decompression method which are corresponding to the compression device and the compressing method, through analyzing input compression code stream data, a decoding tool combination corresponding to the data is selected to decode the data and carry out image reconstruction, and a screen image compression effect of the present invention is raised substantially compared with the prior art.

The invention discloses a still image compression method based on a deep convolutional neural network. The still image compression method mainly comprises the following steps of: carrying out downsampling on an original image at an encoding end and carrying out encoding and decoding by utilizing a JPEG2000 standard; carrying out an inhibition compression effect on a decoded image by utilizing the deep convolutional neural network; reconstructing an inhibition compression effect image by adopting a super-resolution method; carrying out subtraction on the original image and a decoded high-resolution image to obtain a residue image and carrying out targeted encoding; forming bit stream by an encoded low-resolution image, the residual image and auxiliary information and transmitting the bit stream; carrying out decoding by a decoding end to obtain a decoded low-resolution image, residual image and auxiliary information; and processing the decoded low-resolution image to obtain a decoded high-resolution image, carrying out superposition on the decoded high-resolution image and the decoded residual image to obtain a finally decoded high-resolution image. The still image compression method disclosed by the invention has higher rate distortion performance than the JPEG2000 standard.

Apparatus and methods for encoding panoramic content, such as by a wide field of view and large image size. In one implementation, a panoramic image may be mapped to a cube, equirectangular or any other projection e.g., icosahedron or octahedron. Projection may be selected adaptively based on evaluation of the panoramic content. Content evaluation may include obtaining rate distortion cost metric for a given projection configuration including projection type, projection arrangement, and projection orientation. Projection configuration with the lowest cost may be selected as target projection for encoding content. As content composition changes (e.g., object motion, texture presence and/or location) projection may be adaptively selected to match changes in the content. Adaptive content selection methodology may provide for a lower encoded bitrate for a given encoded quality and/or higher quality for a given bitrate.

The invention provides a depth map coding method and a device. The depth map coding method includes establishing a plurality of partition lines which are used for performing wedge-shape partition to a depth macro block, and forming the partition lines into a partition set; using an intra coding mode to code the depth micro block to obtain a first rate-distortion cost value; judging whether an inter coding mode is used for coding the depth micro block and using the inter coding mode to code the depth micro block to obtain a second rate-distortion cost value if the inter coding mode is used for coding the depth micro block; and continuing judging whether the depth micro block contains a discontinuous motion vector field and using a geometric partitioning coding mode to code the depth micro block if the depth micro block contains the discontinuous motion vector field, wherein the geometric partitioning coding mode includes selecting an optimal partition line to partition the depth micro block to obtain a first depth subdomain and a second depth subdomain and subjecting the two subdomains to predictive coding to obtain a third rate-distortion cost value; and comparing the rate-distortion cost values in different coding modes so as to select the coding mode with the minimum rate-distortion cost value for coding the depth micro block. According to the depth map coding method and the device, depth map compression efficiencies are improved, and coding complexities are reduced.

The present invention relates to a selecting method for the optimal mode of the intra prediction coding used for video frequency coding, which belongs to the video frequency coding and decoding field. The steps of the method are that a rate-distortion cost function is constructed on the basis of a prediction code rate; the rate-distortion cost of each prediction mode is calculated by the structured function, and the prediction mode with minimum rate-distortion cost is selected as the optimal mode of the intra prediction coding according to the calculating result. Proportionally, the present invention also provides a device for the selecting of intra prediction coding optimal mode of the video frequency coding. The present invention effectively avoids actually coding every blocks during the rate-distortion optimizing process on the basis that the selected mode is closer to the optimal mode of the original rate-distortion optimization model selecting, and greatly improves the coding efficiency on the precondition of ensuring little change on the code rate and the PSNR of the coding and the full searching method.