Abstract: An example method includes displaying a first interface image. The first interface image is encoded to obtain encoded data of the first interface image. Encoded information of the first interface image is sent to the second electronic device. An ith frame of interface image is displayed in response to an update operation on the first interface image. N difference regions in the ith frame of interface image compared with an (i?1)th frame of interface image are obtained. If an area proportion of the N difference regions in the ith frame of interface image is less than a preset value, image content of the N difference regions is encoded to obtain first encoded data. First encoded information is sent to the second electronic device, where the first encoded information includes the first encoded data and location information of the N difference regions in the ith frame of interface image.

Abstract: Techniques for encoding and decoding image data are described. An image is reconstructed and deblocked. A respective deblocking filter is identified for different color planes of the image. The deblocking filters may include those having different lengths for a luma plane as compared to one or more chroma planes of the image. One or more of the color planes, such as the luma plane, may have different filters for filtering reconstructed pixels vertically as compared to filtering the reconstructed pixels horizontally.

Abstract: A system and method for optimizing video for transmission on a device includes, in one example, the method includes capturing an original video frame and scaling the original video frame down to a lower resolution video frame. The lower resolution video frame is downscaled using a first encoder to produce a first layer output and the first layer output is decoded. The decoded first layer output is upscaled to match a resolution of the original video frame. A difference is obtained between the upscaled decoded first layer output and the original video frame. The difference is independently encoded using a second encoder to create a second layer output. The first and second layer outputs may be stored or sent to another device.

Abstract: The long filter decision in VVC is modified by adding at least one gradient check that at least includes sample p6 or q6. This makes it possible to avoid using the long filters when there is some natural structure at sample p6 or q6. In one specific embodiment at least two gradient checks including both q6 and p6 are added. In another embodiment, the dpq threshold is modified from beta>>2 to beta>>4. This threshold change embodiment may be used in conjunction with or instead of the embodiment in which a gradient check that includes p6 and/or q6 is added to the long filter decision.

Abstract: Embodiments of the present invention relate to methods and systems for ordering, communicating and applying pixel intra-prediction modes.

Abstract: A lossless image compression method using intra-frame prediction is provided. The method includes the steps of: receiving an input image; performing intra-frame prediction on sub-pixels in each color channel of each pixel in the input image to generate first prediction residues; performing inter-color-channel prediction on the first prediction residues to generate second prediction residues; performing remapping on the second prediction residues to obtain third prediction residues in each color channel; and performing Golomb coding and run-length coding on the third prediction residues to generate an image bitstream of the input image.

Abstract: An apparatus of encoding an image can include an intra prediction unit that determines an intra prediction mode of a current prediction unit and generates one or more prediction blocks using the intra prediction mode, an inter prediction unit that determines motion information and generates a prediction block using the motion information, a transform unit that transforms residual signals generated using an original block and the prediction block to generate a transformed block, a quantization unit that determines a quantization parameter and quantizes the transformed block using a quantization matrix and the quantization parameter to generate a quantized block, a scanning unit that determines a scan pattern and applies the scan pattern to the quantized block to generate one-dimensional coefficient information, and an entropy coding unit the entropy-codes one-dimensional coefficient information from the scanning unit, intra prediction information from the intra prediction unit, and motion information from the

Abstract: Provided is a method that de-multiplexes a bit stream to extract intra prediction mode information and residual signals, restores an intra prediction mode of a current prediction unit using the intra prediction information and intra prediction modes of prediction units adjacent to the current prediction unit, generates reference pixels using one or more available reference pixel if there exist unavailable reference pixels of the prediction unit, adaptively filters the reference pixels based on the restored intra prediction mode, generates a prediction block using the restored intra prediction mode and the reference pixels, decodes the residual signal to generating a residual block, and generates a reconstructed block using the prediction block and the residual block. Accordingly, additional bits resulted from increase of a number of intra prediction mode are effectively reduced. Also, an image compression ratio can be improved by generating a prediction block similar to an original block.

Abstract: Described tools and techniques relate to signaling for DC coefficients at small quantization step sizes. The techniques and tools can be used in combination or independently. For example, a tool such as a video encoder or decoder processes a VLC that indicates a DC differential for a DC coefficient, a FLC that indicates a value refinement for the DC differential, and a third code that indicates the sign for the DC differential. Even with the small quantization step sizes, the tool uses a VLC table with DC differentials for DC coefficients above the small quantization step sizes. The FLCs for DC differentials have lengths that vary depending on quantization step size.

Abstract: Provided is an apparatus for encoding a moving picture that determines a quantization step size of a previous coding block according to scan order as the quantization step size predictor of the current coding block when a quantization step size of a left coding block of a current coding block and a quantization step size of an above coding block of the current coding block are unavailable and determines an available motion vector encountered first when retrieving motion vectors in the order of motion vector of a first predetermined position and motion vector of a second predetermined position in a reference picture as a temporal motion vector candidate. Therefore, it is possible to reduce the amount of coding bits required to encode motion information and the quantization step size of the current prediction block.

Abstract: Provided are encoding and decoding methods and apparatuses for a video by selectively determining and using a scan mode. The video encoding method includes: generating transformation coefficients by performing transformation based on a transformation unit to encode an image; determining a scan mode, from among a plurality of scan modes, indicating a scanning direction of the generated transformation coefficients, based on characteristics of the transformation coefficients; and determining and outputting an encoding order of the generated transformation coefficients based on the scanning direction of the determined scan mode.

Abstract: Provided are encoding and decoding methods and apparatuses for a video by selectively determining and using a scan mode. The video encoding method includes: generating transformation coefficients by performing transformation based on a transformation unit to encode an image; determining a scan mode, from among a plurality of scan modes, indicating a scanning direction of the generated transformation coefficients, based on characteristics of the transformation coefficients; and determining and outputting an encoding order of the generated transformation coefficients based on the scanning direction of the determined scan mode.

Abstract: Provided is an apparatus for decoding a moving picture that determines a quantization step size of a previous coding block according to scan order as the quantization step size predictor of the current coding block when a quantization step size of a left coding block of a current coding block and a quantization step size of an above coding block of the current coding block are unavailable and determines an available motion vector encountered first when retrieving motion vectors in the order of motion vector of a first predetermined position and motion vector of a second predetermined position in a reference picture as a temporal motion vector candidate. Therefore, it is possible to reduce the amount of coding bits required to decode motion information and the quantization step size of the current prediction block.

Abstract: Provided is an apparatus for decoding a moving picture that determines a quantization step size of a previous coding block according to scan order as the quantization step size predictor of the current coding block when a quantization step size of a left coding block of a current coding block and a quantization step size of an above coding block of the current coding block are unavailable and determines an available motion vector encountered first when retrieving motion vectors in the order of motion vector of a first predetermined position and motion vector of a second predetermined position in a reference picture as a temporal motion vector candidate. Therefore, it is possible to reduce the amount of coding bits required to decode motion information and the quantization step size of the current prediction block.

Abstract: Provided are encoding and decoding methods and apparatuses for a video by selectively determining and using a scan mode. The video encoding method includes: generating transformation coefficients by performing transformation based on a transformation unit to encode an image; determining a scan mode, from among a plurality of scan modes, indicating a scanning direction of the generated transformation coefficients, based on characteristics of the transformation coefficients; and determining and outputting an encoding order of the generated transformation coefficients based on the scanning direction of the determined scan mode.

Abstract: This disclosure describes techniques for intra-prediction mode signaling for video coding. In one example, a video coder is configured to determine, for a block of video data, a set of most probable intra-prediction modes such that the set of most probable intra-prediction modes has a size that is equal to a predetermined number that is greater than or equal to two. The video coder is also configured to code a value representative of an actual intra-prediction mode for the block based at least in part on the set of most probable intra-prediction modes and code the block using the actual intra-prediction mode. The video coder may further be configured to code the block using the actual intra-prediction mode, e.g., to encode or decode the block. Video encoders and video decoders may implement these techniques.

Abstract: Provided is an image decoding apparatus that restores a quantized transform block by inversely scanning 1D quantized coefficients, inversely quantizes the quantized transform block using a quantization step size, inversely transforms the transform block to generate a residual block, and generates a prediction block according to an intra prediction mode. When a size of the transform block is 8×8, the quantized transform block is divided into a plurality of sub-blocks, and the plurality of sub-blocks and coefficients of each sub-block are scanned using a same scan pattern determined according to the intra prediction mode. When the intra prediction mode is a horizontal mode, the scan pattern is a vertical scan.

Abstract: Provided is an image decoding apparatus that receives an intra prediction mode and one-dimensional (1D) quantized coefficients, restores a quantized transform block by inversely scanning the 1D quantized coefficients, inversely quantizes the quantized transform block using a quantization step size, inversely transforms the transform block to generate a residual block, and generates a prediction block according to the intra prediction mode. When a size of the transform block is 8×8, the quantized transform block is divided into a plurality of sub-blocks, and the plurality of sub-blocks and coefficients of each sub-block are scanned using a same scan pattern determined according to the intra prediction mode. When the intra prediction mode is a horizontal mode, the scan pattern is a vertical scan.

Abstract: The invention provide an apparatus that enables encoding while suppressing a maximum distortion due to a compression of pixel values to an allowable error. The apparatus comprises a setting unit that sets transformation information for transforming a pixel value of a target image into a second pixel value in accordance with the allowable error information; a transformation unit that transforms each pixel value of the image based on the transformation information to generate a second image; a first unit that encodes the second image using an encoding unit for encoding such that a difference in a pixel value before and after encoding is within a constant ?; and a second unit that generates inverse transformation information for transforming a pixel value of the second image into a value related to a pixel value of the target image, and lossless-encodes the generated information.

Abstract: A method and apparatus for improved intra prediction mode coding are disclosed. Intra prediction exploits the spatial correlation within a picture or within a picture region. In High-Efficiency Video Coding (HEVC), a coding scheme for the intra luma prediction mode is considered, where the intra prediction mode of a current block is compared with the minimum of two intra luma prediction modes corresponding to two neighboring blocks. If the intra prediction mode of the current block is the same as the minimum of the two neighboring intra luma prediction modes, a single bit is transmitted to indicate the case. Otherwise, information for the current intra prediction mode is transmitted in fixed-length codeword. The present invention provides multiple intra prediction mode candidates based on neighboring intra prediction modes so that there is a better chance for predictor hit. Accordingly, improved coding efficiency is achieved.

Abstract: Provided is an image encoding apparatus that generates a prediction block according to an intra prediction mode, generates a residual block, transforms the residual block to generate a transform block, quantizes the transform block to generate a quantized transform block, scans the quantized transform block to generate one-dimensional (1D) quantized coefficients, and entropy-codes the 1D quantized coefficients. When a size of the transform block is 8×8, the quantized transform block is divided into a plurality of sub-blocks, the plurality of sub-blocks are scanned and coefficients of each sub-block are scanned using a scan pattern determined according to the intra prediction mode. The scan pattern for scanning the plurality of sub-blocks is the same as the scan pattern for scanning the coefficients of each sub-block and when the intra prediction mode is a horizontal mode, the scan pattern is a vertical scan.

Abstract: Provided is an image decoding apparatus that receives an intra prediction mode and one-dimensional (1D) quantized coefficients, restores a quantized transform block by inversely scanning the 1D quantized coefficients, inversely quantizes the quantized transform block using a quantization step size to generate a transform block, inversely transforms the transform block to generate a residual block, and generates a prediction block according to the intra prediction mode. When a size of the transform block is 8×8, the quantized transform block is divided into a plurality of sub-blocks, and the plurality of sub-blocks and coefficients of each sub-block are scanned using a same scan pattern determined according to the intra prediction mode.

Abstract: Provided is an image encoding apparatus that generates a prediction block according to an intra prediction mode, generates a residual block, transforms the residual block to generate a transform block, quantizes the transform block to generate a quantized transform block, scans the quantized transform block to generate one-dimensional (1D) quantized coefficients, and entropy-codes the 1D quantized coefficients. When a size of the transform block is 8×8, the quantized transform block is divided into a plurality of sub-blocks, the plurality of sub-blocks are scanned are coefficients of each sub-block are scanned using a same scan pattern determined according to the intra prediction mode. The quantized coefficients of each sub-block are scanned in a reverse direction from a last non-zero coefficient according the scan pattern.

Abstract: Provided is an image encoding apparatus that generates a prediction block according to an intra prediction mode, generates a residual block, transforms the residual block to generate a transform block, quantizes the transform block to generate a quantized transform block, scans the quantized transform block to generate one-dimensional (1D) quantized coefficients, and entropy-codes the 1D quantized coefficients. When a size of the transform block is 8×8, the quantized transform block is divided into a plurality of sub-blocks, the plurality of sub-blocks and coefficients of each sub-block are scanned using a same scan pattern determined according to the intra prediction mode. When the intra prediction mode is a horizontal mode, the scan pattern is a vertical scan. The intra prediction mode is coded using an upper and a left intra prediction modes.

Abstract: Provided is an image encoding apparatus that generates a prediction block according to an intra prediction mode, generates a residual block, transforms the residual block to generate a transform block, quantizes the transform block to generate a quantized transform block, scans the quantized transform block to generate one-dimensional (1D) quantized coefficients, and entropy-codes the 1D quantized coefficients. When a size of the transform block is 8×8, the quantized transform block is divided into a plurality of sub-blocks after quantization of the transform block, the plurality of sub-blocks are scanned using a first scan pattern determined according to the intra prediction mode, and coefficients of each sub-block are scanned using a second scan pattern determined according to the intra prediction mode. The first scan pattern is a scan order applied to the plurality of sub-blocks. The second scan pattern is a scan order applied to the coefficients of each sub-block.

Abstract: Provided is an image decoding apparatus that receives an intra prediction mode and one-dimensional (1D) quantized coefficients, restores a quantized transform block by inversely scanning the 1D quantized coefficients, inversely quantizes the quantized transform block using a quantization step size to generate a transform block, inversely transforms the transform block to generate a residual block, and generates a prediction block according to the intra prediction mode. When a size of the transform block is 8×8, the quantized transform block is divided into a plurality of sub-blocks, and the plurality of sub-blocks and coefficients of each sub-block are scanned using a same scan pattern determined according to the intra prediction mode. When the intra prediction mode is a horizontal mode, the scan pattern is a vertical scan.

Abstract: Provided is an image encoding apparatus that generates a prediction block according to an intra prediction mode, generates a residual block, transforms the residual block to generate a transform block, quantizes the transform block to generate a quantized transform block, scans the quantized transform block to generate one-dimensional (1D) quantized coefficients, and entropy-codes the 1D quantized coefficients. When a size of the transform block is 8×8, the quantized transform block is divided into a plurality of sub-blocks, the plurality of sub-blocks and coefficients of each sub-block are scanned using a same scan pattern determined according to the intra prediction mode. A scan pattern for scanning flags indicating non-zero coefficients of each sub-block is the same as the scan pattern for scanning non-zero coefficients of each sub-block.

Abstract: Provided are encoding and decoding methods and apparatuses for a video by selectively determining and using a scan mode. The video encoding method includes: generating transformation coefficients by performing transformation based on a transformation unit to encode an image; determining a scan mode, from among a plurality of scan modes, indicating a scanning direction of the generated transformation coefficients, based on characteristics of the transformation coefficients; and determining and outputting an encoding order of the generated transformation coefficients based on the scanning direction of the determined scan mode.

Abstract: Embodiments of the present invention relate to methods and systems for ordering, communicating and applying pixel intra-prediction modes.

Abstract: An image decoding apparatus is provided. The image decoding apparatus includes a processor which obtains information about a color representation from a bitstream, obtains a residue, which corresponds to a difference between a current image and a predicted image of the current image, from the bitstream, and reconstructs the current image by using the residue and the predicted image, based on the information about the color representation.

Abstract: Provided is an intra prediction decoding apparatus that restores quantized residual coefficients, intra prediction information and size information on a prediction unit from a received bit stream, restores an intra prediction mode of the current prediction unit on the basis of the intra prediction information and the size information on the current prediction unit, generates unavailable reference pixels of the prediction unit, and adaptively filters the reference pixels on the basis of the intra prediction mode. Also, the apparatus generates a prediction block by adaptively filtering reference pixels corresponding to the intra prediction mode. Then, the apparatus generates a restoration image using the prediction block and a restored residual block. Accordingly, a prediction block close to an original image can be restored, and an image compression ratio can be improved.

Abstract: A method for encoding pictures within a groups of pictures using prediction, where a first reference picture from a group of pictures and a second reference pictures from the subsequent group of pictures are used in predicting pictures in the group of pictures associated with the first reference picture. A plurality of anchor pictures in the group of pictures associated with the first reference picture may be predicted using both the first and second reference pictures to ensure a smooth transition between different groups of pictures within a video frame.

Abstract: There are provided a method and apparatus for adaptive weight selection for motion compensated prediction. The apparatus includes an encoder for encoding a picture by deriving a set of weighting parameters, selecting at least one weighting parameter in the set based upon a selection criteria, and applying the selected at least one weighting parameter to a reference picture used to encode the picture.

Abstract: A method of decoding a video signal on a decoding apparatus includes receiving prediction mode information, interpolating information and a residual of a current block, reconstructing an interpolating pixel using the interpolating information and a neighbor block, and reconstructing the current block using the interpolating pixel, the prediction mode information and the residual, wherein the interpolating information is generated based on a location of the current block. High reconstruction rate can be obtained by improving the related art method having limited intra prediction modes available for a current block located on a boundary area of a picture in encoding in a manner of reconstructing and using an interpolating pixel based on interpolating information.