308 results about "Coding tree unit" patented technology

There are disclosed various methods, apparatuses and computer program products for video encoding. In some embodiments the method comprises obtaining a coding unit of a coding tree unit of a picture comprising a refreshed region and a non-refreshed region and a virtual boundary between the refreshed region and the non-refreshed region; examining whether the coding unit belongs to the refreshed region or to the non-refreshed region; treating the virtual boundary as a picture boundary when determining that the coding unit belongs to the refreshed region; or treating the virtual boundary as no boundary when determining that the coding unit belongs to the non-refreshed region.

A method of decoding JVET video that includes receiving a bitstream indicating how a coding tree unit was partitioned into coding units, and parsing said bitstream to generate at least one predictor based on an intra prediction mode signaled in the bitstream, the intra prediction mode selected from a plurality of intra prediction modes for calculating a prediction pixel P[x,y] at coordinate x,y for the coding unit. A number of intra prediction modes available for coding the coding unit are reduced by replacing two or more non-weighted intra prediction modes by a weighted intra prediction mode.

According to the present disclosure, an image decoding method performed by a decoding device includes the steps of acquiring image information including prediction-related information from a bitstream; deriving an intra prediction mode with respect to a current block on the basis of the prediction-related information; generating prediction samples with respect to the current block on the basis of the intra prediction mode with respect to the current block; and generating reconstruction samples with respect to the current block on the basis of the prediction samples with respect to the current block, wherein the intra prediction mode is derived on the basis of whether an upper neighboring block of the current block exists in the same coding tree unit (CTU) as the current block.

An encoder includes circuitry and memory coupled to the circuitry. In operation, the circuitry encodes subpicture information in which a horizontal position and a vertical position of a region of a subpicture are represented in a unit of a coding tree unit (CTU). The subpicture is a rectangular region in a picture. The horizontal position is represented by a first position of a first CTU in the subpicture, the first position being relative to a left end of the picture. The vertical position is represented by a second position of a second CTU in the subpicture, the second position being relative to a top end of the picture.

A method of decoding JVET video that includes receiving a bitstream indicating how a coding tree unit was partitioned into coding units, and parsing said bitstream to generate at least one predictor based on an intra prediction mode signaled in the bitstream, the intra prediction mode selected from a plurality of intra prediction modes for calculating a prediction pixel P[x,y] at coordinate x,y for the coding unit. A number of intra prediction modes available for coding the coding unit are reduced by replacing two or more non-weighted intra prediction modes by a weighted intra prediction mode.

The invention relates to a target detection enhanced video code rate control method, and belongs to the technical field of video compression. The method comprises the following steps: preprocessing each frame of image of an input video, dividing a plurality of coding tree units in each frame of image, and calculating gradient features of the image and the coding tree units; the video is coded through different quantization parameters, and the code rate of the coded video and the distortion degree of the video are calculated; fitting a cubic logarithmic model to establish a relationship between the distortion degree and the code rate of the video by combining the gradient characteristics of each frame and the distortion degree and the code rate of the video; marking the ROI region of each image frame of the input video through a target detection network, and dividing the compensation level of the coding tree unit in combination with the ROI region and the gradient feature of the coding tree unit; and in combination with the compensation level of each coding tree unit, through a code rate allocation mechanism, allocating a coding code rate to each coding tree unit in each image frame of the input video. According to the invention, the video compression process can be optimized, and the overall performance of the compressed video is improved.

A zero-delay panoramic video bit rate control method that considers distortion temporal propagation aims to optimize target bit allocation and achieve global rate-distortion optimization in coding. It encompasses coding tree unit (CTU)-level bit rate control and temporal global rate-distortion optimization. CTU-level bit rate control involves optimizing target bit allocation and updating bit rate control parameters. Temporal global rate-distortion optimization utilizes the reconstruction error and motion compensation prediction error information of the previous coded frame to estimate the temporal dependence between CTUs in the current coding frame and those in the previous coded frame to adjust the coding parameters of the current CTU. The coding parameters are further fine-tuned according to the area stretching ratio encountered during the projection of the panoramic video from a 3D spherical surface to a 2D plane, taking into consideration the detrimental impact of interpolated redundant pixels on the coding process.

An image prediction method, apparatus, and system, a device, and a storage medium are provided. The method includes: (401) obtaining a split mode of a current node, where the current node is an image block in a coding tree unit in a current image; (402) determining, based on the split mode of the current node and a size of the current node, whether the current node satisfies a first condition; and (403) when it is determined that the current node satisfies the first condition, performing intra prediction on all coding blocks belonging to the current node, to obtain predictors of all the coding blocks belonging to the current node.

Systems, methods, and instrumentalities may perform CTU grid shifting. In examples, a device may include a processor. The device may be configured to obtain a picture comprising a plurality of coding tree units (CTU). The device may select a CTU grid shift value based on an associated feature value. The CTU grid shift value may be selected from a plurality of CTU grid shift values. In examples, each CTU grid shift value from the plurality of CTU grid shift values may be associated with a respective feature value. The device may encode the picture based on the selected CTU grid shift value. In examples, the associated feature value may indicate at least one of an activity value, a block boundary activity of blocks, one or more spatial gradients, or a number of blocks associated with an intra block copy (IBC).

Aspects of the disclosure includes methods and apparatuses for video decoding and video encoding and a method of processing visual media data. A current block in a first coding tree unit (CTU) is predicted using samples in a current picture. The first CTU and a second CTU are processed in parallel. The method for video decoding includes determining one of (i) a reference block of the current block in an allowed search range that is constrained for parallel processing of the first CTU and the second CTU in the current picture and (ii) an intra prediction mode of the current block based on a template adjacent to the current block that is constrained for parallel processing of the first CTU and the second CTU, and reconstructing the current block using the one of (i) the reference block and (ii) the intra prediction mode.

A video coding method, an encoder, and a decoder are disclosed. The method is applied to a decoder and comprises retrieving a bitstream corresponding to a current frame and parsing the bitstream to obtain a current coding tree unit (CTU) of the current frame; determining an availability of at least one neighbouring CTU of the current CTU in the current frame according to a wavefront delay, wherein the wavefront delay is a delay in units of CTUs in a row direction between the current CTU at a current CTU row and the neighbouring CTU at a previous CTU row which are decoded in parallel; determining a prediction block in the at least one neighbouring CTU for a current coding unit (CU) in the current CTU; and decoding the current CU using the prediction block.

An image decoding method comprises the steps of: obtaining a current coding tree unit (CTU) of a first size configuring a current picture; determining whether to implicitly divide the current coding tree unit; dividing the current coding tree unit into one or more coding units (CUs) based on the determination; obtaining, from a bitstream, division information for a current coding unit among the one or more coding units; and dividing and decoding the current coding unit..

A method, apparatus, and computer program product provide for management of luma mapping with chroma scaling (LMCS) processes for Gradual Decoding Refresh (GDR) pictures. In the context of a method, the method accesses a picture to be decoded and determines whether the picture is within a GDR period. The method can also prevent a LMCS decoding process from being applied to the picture within the GDR period. Another method can determine whether a virtual boundary is within a current coding tree unit of a picture with a GDR period and if so, prevent a chroma residual scaling decoding process associated with LMCS from being applied to one or more coding units within a clean area. Another method can pad a neighboring pixel area from one or more reconstructed pixels in a clean area for a chroma residual scaling decoding process associated with LMCS.

The invention relates to the technical field of video image compression, in particular to a video image compression algorithm based on an H.266 / VVC standard, which comprises the steps of generating a visual attention thermodynamic diagram through time-space domain saliency detection, adjusting a coding tree unit QP value in a partitioned manner to realize adaptive quantization, and designing an asymmetric quantization matrix to optimize a transformation quantization effect. And the generative adversarial network is used to enhance the quality of the reconstructed frame. According to the method, the blocking effect of a complex texture region can be effectively inhibited, the quantization distortion of a human eye sensitive region is reduced, the edge preserving capability is improved, the subjective visual quality and compression efficiency of the video are remarkably improved, and the high-definition video transmission requirement is met.

Methods are described for template matching (TM) in video coding. The proposed methods include: the use of constrained top and left neighbors in template matching, enabling TM only in coding tree unit boundaries, using approximated reconstructed samples, a new processing pipeline for deriving decoder side intra mode derivation (DIMD) combined with template based intra mode derivation (TIMD), and using filtered pixels from the neighbors, instead of using the reconstructed pixels. Furthermore, methods are described on how template matching may be applied in combination with Intra, sub-partitioning mode, interpolation filtering in intra prediction, block partitioning, bi-prediction with coding unit-level weights, and adaptive motion vector resolution.

A method for encoding a video picture into a bitstream of encoded video picture data, includes: splitting the video picture into rectangular picture areas, a size of at least one rectangular picture area being different from an integer multiple of a default size of coding-tree unit encoded into the bitstream; determining a grid of coding-tree units for each rectangular picture area, a grid of coding-tree units representing a spatial partition of a rectangular picture area, each coding-tree unit representing a sub-area of a rectangular picture area, the sub-area being subdivided according to a coding tree; obtaining encoded video picture data by encoding at least one coding unit (CU) of a coding tree associated with each coding tree unit (CTU) of each grid of coding-tree unit; and writing the encoded video picture data into the bitstream.

A method of partitioning in video coding for JVET, comprising representing a JVET coding tree unit as a root node in a quadtree plus binary tree (QTBT structure that can have quadtree or binary partitioning of the root node and quadtree or binary trees branching from each of the leaf nodes. The partitioning at any depth can use asymmetric binary partitioning to split a child node represented by a leaf node into two child coding units of unequal size, representing the two child coding units as leaf nodes in a binary tree branching from the parent leaf node and coding the child coding units represented by final leaf nodes of the binary tree with JVET. Disclosed is a generalized method of partitioning a block, either square or rectangular, which leads to more flexible block sizes with possible higher coding efficiency.

The invention relates to an entropy decoding processing method and device, computer equipment, a computer readable storage medium and a computer program product. The method comprises the following steps: for a context model of each intra-frame coding strip, if a current syntax element is a first type syntax element, initializing the current context model, and determining a context variable in the current context model; the first type syntax element comprises a first syntax element of a first coding tree unit of a slice, slice or coding tree unit row; analyzing the current syntax element through the initialized current context model; and storing the context variables in each current context model until the current syntax element is the second type syntax element. By adopting the method, the data volume processed in the entropy decoding process can be reduced, the processing time is shortened, and the processing efficiency is improved.

A method, apparatus, and computer program product provide for management of luma mapping with chroma scaling (LMCS) processes for Gradual Decoding Refresh (GDR) pictures. In the context of a method, the method accesses a picture to be decoded and determines whether the picture is a GDR picture. The method can also prevent a LMCS decoding process from being applied to the GDR picture. Another method can determine whether a virtual boundary is within a current coding tree unit of the gradual decoding refresh picture and if so, prevent a chroma residual scaling decoding process associated with LMCS from being applied to one or more coding units within a clean area. Another method can pad a neighboring pixel area from one or more reconstructed pixels in a clean area for a chroma residual scaling decoding process associated with LMCS.

System, methods, and instrumentalities are disclosed for video encoding / decoding. For example, a device for video encoding and / or decoding (e.g., a video encoder and / or a video decoder) may be configured for a spatial context-adaptive binary arithmetic coding (CABAC) tuning. The device may determine whether a current coding unit (CU) is located at the beginning of a current coding tree unit (CTU) in a scanning order. Based on a determination that the current CU is located at the beginning of the current CTU in a scanning order, the device may determine at least one neighboring sample that is present for the spatial CABAC tuning for video decoding and / or video encoding. The at least one neighboring sample may be associated with a neighboring CTU that is not located in the current CTU. The device may decode / encode the current CU based on the determined at least one neighboring sample.

The present application relates to the technical field of video coding, and especially relates to a coding unit division fast decision method and system based on multi-functional video coding, comprising constructing a quadtree division prediction network, using the network to judge whether a coding tree unit needs to perform quadtree division, and obtaining a coding unit after performing the quadtree division; constructing a mixed tree division prediction network, using the network to judge whether the coding unit needs to be divided, stopping division if the coding unit does not need to be divided, otherwise judging whether the coding unit adopts binary tree division or ternary tree division, and taking a smaller coding unit division prediction value in parallel branches as a final prediction result. The present application improves coding efficiency, and can balance the relationship between visual quality and coding efficiency by selecting different threshold values according to specific scene needs.

The invention provides a video coding method, which comprises the following steps of: inputting a coding tree unit to be coded, and extracting texture features of a coding block, the texture features comprising local binary pattern similarity of all pixel points in the coding block and direction dispersion of each pixel point; inputting the texture features into the trained multi-type division prediction architecture, and sequentially judging whether to execute quadtree division, horizontal or vertical division, horizontal binary tree or ternary tree division and vertical binary tree or ternary tree division or not through a binary classification problem method; and calculating the rate distortion cost under each division mode to obtain an optimal division mode and a suboptimal division mode of the coding block, and outputting an optimal mode or a combination of the optimal mode and the suboptimal mode. According to the invention, the accuracy of the prediction mode in coding is improved.

The present invention belongs to the field of image processing technology, and specifically relates to a zero-delay panoramic video rate control method considering the propagation of time domain distortion. The method of the present invention is mainly to optimize the target bit allocation and global rate distortion optimization coding, including rate control at the coding tree unit (CTU) level and time domain global rate distortion optimization. CTU-level rate control mainly includes optimizing target bit allocation and updating rate control parameters; time domain global rate distortion optimization mainly uses the reconstruction error and motion compensation prediction error information of the encoded frame to estimate the time domain dependency of each CTU in the current encoded frame and adjust the rate distortion optimization parameters of the CTU accordingly, and at the same time, according to the process of projecting the panoramic spherical graphic onto the 2D plane (ERP projection), the characteristics of oversampling and increasing pixel redundancy will be generated at the two poles, and the coding parameters are adjusted according to the projection area change ratio. The present invention can effectively shorten the encoding time and improve the video encoding quality under the condition of a given bandwidth.

The invention provides an image processing apparatus, an image processing method, and a bitstream transmission apparatus. An image processing device for processing a picture including a sub-picture including one or more CTUs (Code Tree Units), the image processing device comprising: a memory; and a circuit connected to the memory, the circuit performing a process of determining whether (i) a third value, which is a product of a CTU size and a sum of a first value indicating a left end of the sub-picture and a second value indicating a width of the sub-picture, and (ii) the width of the picture is smaller, and if the third value is smaller than the width of the picture, determining whether the width of the picture is smaller or not, and if the third value is smaller than the width of the picture, the width of the sub-picture is smaller than the width of the sub-picture, the width of the sub-picture is smaller than the width of the sub-picture. When the width of the picture is smaller than the third value, the product of the second value and the CTU size is derived as the width of the sub-picture, and when the width of the picture is smaller than the third value, the difference between the width of the picture and the product of the first value and the CTU size is derived as the width of the sub-picture.

Describes several techniques for video encoding and video decoding. An example method includes: performing a conversion between a video including one or more video pictures and a bitstream of the video, where each video picture includes one or more slices, the one or more slices include one or more slice columns, the bitstream conforms to format rules, and the format rules specify deriving a slice column index for each coding tree unit column of the slices of the video picture.

A decoding method includes: decoding a bitstream to determine a related syntax element of a current coding tree unit; determining a geometric transformation type of the current coding tree unit according to the related syntax element; determining reference sample information of the current coding tree unit; performing geometric transformation on the reference sample information of the current coding tree unit according to the geometric transformation type, to obtain geometric transformed reference sample information; inputting the geometric transformed reference sample information of the current coding tree unit to a neural network based in-loop filter model for filtering, to output filtered reconstructed sample information; and performing inverse geometric transformation on the filtered reconstructed sample information according to the geometric transformation type, to obtain final reconstructed sample information of the current coding tree unit.

The present invention relates to an in-frame mode JVET coding method. A method for coding JVET segmented video coding blocks, wherein the MPM set includes a set excluding six in-frame prediction coding modes, and can be coded using truncated unary binarization, 16 selected in-frame prediction coding modes can be coded using 4-bit fixed-length codes, and the remaining unselected coding modes can be coded using truncated binary coding, and the JVET coding tree unit can be compiled into a root node in a quadtree plus binary tree (QTBT) structure, which can have a quadtree branching from the root node and a binary tree branching from the leaf nodes of each quadtree using asymmetric binary splitting to separate the coding unit represented by the quadtree leaf node into child nodes, which represent the child nodes as leaf nodes in the binary tree branching from the quadtree leaf node.

The embodiment of the present invention provides an image coding method and device (encoder and / or decoder). A history-based motion vector prediction (HMVP) list corresponding to a current coding tree unit (CTU) row in a block of an image is initialized, and a CTU in the current CTU row is processed according to the initialized HMVP list.

A method of decoding coding blocks of a coding tree unit for an image frame, from a bitstream. The method comprises determining a chroma format of the image frame, the chroma format having chroma channels of the image frame being subsampled relative to a luma channel of the image frame; and determining, based on the determined chroma format, a size of a chroma coding block of one of the chroma channels of the coding tree unit, wherein the chroma coding block is collocated with a plurality of corresponding luma blocks. The method comprises determining the chroma coding block is encoded using intra prediction if the determined size of the chroma block is a predetermined minimum chroma block size; and decoding the coding blocks of the coding tree using intra prediction for the chroma coding block and inter prediction for at least one of the plurality of corresponding luma coding blocks.