Patent classifications
H04N19/649
INTRA PREDICTION MODE DERIVATION FOR CHROMINANCE VALUES
A video coding or decoding method in which luminance and chrominance samples are predicted from other respective reference samples according to a prediction direction associated with a current sample to be predicted, the chrominance samples having a lower horizontal and/or vertical sampling rate than the luminance samples so that the ratio of luminance horizontal resolution to chrominance horizontal resolution is different than the ratio of luminance vertical resolution to chrominance vertical resolution, so that a block of luminance samples has a different aspect ratio to a corresponding block of chrominance samples, the method including: detecting a first prediction direction defined in relation to a first grid of a first aspect ratio in respect of a set of current samples to be predicted; and applying a direction mapping to the prediction direction to generate a second prediction direction defined in relation to a second grid of a different aspect ratio.
DATA ENCODING AND DECODING
A video coding or decoding method using inter-image prediction to encode input video data in which each chrominance component has 1/Mth of the horizontal resolution and 1/Nth of the vertical resolution of the luminance component, where M and N are integers equal to 1 or more, including storing one or more images preceding a current image, interpolating a higher resolution version of prediction units of the stored images so that the luminance component has a horizontal resolution P times that of the corresponding portion of the stored image and a vertical resolution Q times that of the corresponding portion of the stored image, detecting inter-image motion between a current image and the one or more interpolated stored images so as to generate motion vectors between a prediction unit of the current image and areas of the one or more preceding images, and generating a motion compensated prediction.
Filtering of prediction units according to intra prediction direction
A video coding or decoding method in which luminance and chrominance samples in a 4:4:4 format or a 4:2:2 format are predicted from other respective samples according to a prediction direction associated with blocks of samples to be predicted; comprises detecting a prediction direction in respect of a current block to be predicted; generating a predicted block of chrominance samples according to other chrominance samples defined by the prediction direction; if the detected prediction direction is substantially vertical, filtering the left column of samples in the predicted block of chrominance samples, or if the detected prediction direction is substantially horizontal, filtering the top row of samples in the predicted block of chrominance samples; and encoding a difference between the filtered predicted chrominance block and the actual chrominance block or applying a decoded difference to the filtered predicted chrominance block so as to encode or decode the block respectively.
Quantization for different color sampling schemes
A video encoding method for encoding both the 4:2:0 video and 4:4:4 video formats. The method includes generating blocks of quantized spatial frequency data by quantizing coefficients and generating a matrix of data. The method further includes determining quantization matrices for use with at least two block sizes. The method further includes determining a first quantization matrix for a 3232 chroma block of samples with respect to a first modification of a first scaling list for quantization of a block of samples smaller than 3232, and determining, for blocks of another block size different than the 3232 chroma block of samples, a second quantization matrix by modifying a second scaling list according to a second modification. The second scaling list is different from the first scaling list, and the first scaling list is a reference scaling list for video in 4:2:0 video format.
Systems and methods for mask based processing of a block of a digital image
There is provided an apparatus for generating a set of transform coefficients of a block in a frame or portion thereof. The apparatus includes a media encoder coupled to a data interface configured to receive a frame or portion thereof. The media encoder is configured to: designate a rotational symmetry mask having a size and a shape as the block partitioned in the frame or portion thereof for processing the block; split the block to two complementary portions using the rotational symmetry mask; generate a pair of rotational symmetry blocks each having one of the two complementary portions; and compute a transform coefficient for each member of the pair of rotational symmetry blocks.
Methods and Apparatuses for Encoding and Decoding Digital Light Field Images
A method for encoding a raw lenselet image includes a receiving phase, wherein at least a portion of a raw lenselet image is received, the image including a plurality of macro-pixels, each macro-pixel having pixels corresponding to a specific view angle for the same point of a scene, and an output phase, wherein a bitstream having at least a portion of an encoded lenselet image is outputted. The method has an image transform phase, wherein the pixels of said raw lenselet image are spatially displaced in a transformed multi-color image having a larger number of columns and rows with respect to the received raw lenselet image, wherein dummy pixels having undefined value are inserted into the raw lenselet image and wherein the displacement is performed so as to put the estimated center location of each macro-pixel onto integer pixel locations. Moreover, the method includes a sub-view generation phase, wherein a sequence of sub-views is generated, said sub-views having pixels of the same angular coordinates extracted from different macro-pixels of the transformed raw lenselet image. Finally, the method has a graph coding phase, wherein a bitstream is generated by encoding a graph representation of at least one of the sub-views of the sequence according to a predefined graph signal processing technique.
FAST AND ACCURATE BLOCK MATCHING FOR COMPUTER-GENERATED CONTENT
A set of software applications configured to perform interframe and/or intraframe encoding operations based on data communicated between a graphics application and a graphics processor. The graphics application transmits a 3D model to the graphics processor to be rendered into a 2D frame of video data. The graphics application also transmits graphics commands to the graphics processor indicating specific transformations to be applied to the 3D model as well as textures that should be mapped onto portions of the 3D model. Based on these transformations, an interframe module can determine blocks of pixels that repeat across sequential frames. Based on the mapped textures, an intraframe module can determine blocks of pixels that repeat within an individual frame. A codec encodes the frames of video data into compressed form based on blocks of pixels that repeat across frames or within frames.
FILTERING OF PREDICTION UNITS ACCORDING TO INTRA PREDICTION DIRECTION
A video coding or decoding method in which luminance and chrominance samples in a 4:4:4 format or a 4:2:2 format are predicted from other respective samples according to a prediction direction associated with blocks of samples to be predicted; comprises detecting a prediction direction in respect of a current block to be predicted; generating a predicted block of chrominance samples according to other chrominance samples defined by the prediction direction; if the detected prediction direction is substantially vertical, filtering the left column of samples in the predicted block of chrominance samples, or if the detected prediction direction is substantially horizontal, filtering the top row of samples in the predicted block of chrominance samples; and encoding a difference between the filtered predicted chrominance block and the actual chrominance block or applying a decoded difference to the filtered predicted chrominance block so as to encode or decode the block respectively.
Intra prediction mode derivation for chrominance values
A video coding or decoding method in which luminance and chrominance samples are predicted from other respective reference samples according to a prediction direction associated with a current sample to be predicted, the chrominance samples having a lower horizontal and/or vertical sampling rate than the luminance samples so that the ratio of luminance horizontal resolution to chrominance horizontal resolution is different than the ratio of luminance vertical resolution to chrominance vertical resolution, so that a block of luminance samples has a different aspect ratio to a corresponding block of chrominance samples, the method including: detecting a first prediction direction defined in relation to a first grid of a first aspect ratio in respect of a set of current samples to be predicted; and applying a direction mapping to the prediction direction to generate a second prediction direction defined in relation to a second grid of a different aspect ratio.
Systems and methods for processing a digital image
An apparatus adapted, including a media encoder coupled to a data interface adapted to receive a frame or portion thereof. The media encoder is adapted to iteratively subdivide each block of a plurality of blocks partitioned in a frame or portion thereof and to process a subdivided block of the plurality of blocks, during each iteration of a plurality of iterations, by selecting a rotational symmetry mask fulfilling an efficiency measure for coding said block, the rotational symmetry mask selected from a plurality of rotational symmetry masks which define a plurality of different rotational symmetries in a multidimensional space, splitting the subdivided block to two complementary portions based on the rotational symmetry mask, generating a pair of rotational symmetry blocks each having one of said two complementary portions, and computing a plurality of transform coefficients from the pair of rotational symmetry blocks.