Abstract:
A method for selecting a motion vector predictor is provided. The method of selecting a motion vector predictor includes the steps of selecting motion vector predictor candidates for a current block and selecting a motion vector predictor of the current block out of the motion vector predictor candidates, wherein the motion vector predictor candidates for the current block include a motion vector of a first candidate block which is first searched for as an available block out of left neighboring blocks of the current block and a motion vector of a second candidate block which is first searched for as an available block out of upper neighboring blocks of the current block.
Abstract:
An intra prediction method and a device using the intra prediction method are provided. The intra prediction method includes the steps of: deriving a current prediction mode as a prediction mode of a current block; constructing neighboring samples of the current block with available reference samples; filtering the available reference samples; and generating predicted samples of the current block on the basis of the filtered available reference samples. The filtering step includes performing the filtering using the available reference sample located in the prediction direction of the current prediction mode and a predetermined number of available reference samples neighboring to the prediction direction of the current prediction mode.
Abstract:
The present invention relates to a method for decoding a video signal, comprising the steps of: acquiring a transform size flag of the current macroblock from a video signal; checking the number of non-zero transform coefficients at each pixel position in a first transform block which corresponds to the transform size flag; changing a scan order of the first transform block by prioritizing the position of the pixel having the greatest number of the non-zero transform coefficients in the first transform block; determining the number of the non-zero transform coefficients at each pixel position in a second transform block, and setting the changed scan order of the first transform block as an initialized scan order of the second transform block; adding the number of the non-zero transform coefficients at each pixel position in the first transform block and the number of the non-zero transform coefficients at each pixel position in the second transform block, and changing the scan order of the second transform block by prioritizing the position of the pixel having the greatest number of the non-zero transform coefficients; and decoding the transform coefficients arranged in the scan order changed in the previous step, wherein the first transform block and the second transform block have sizes corresponding to the transform size flag, and are contained in the current macroblock.
Abstract:
A method for selecting a motion vector predictor is provided. The method of selecting a motion vector predictor includes the steps of selecting motion vector predictor candidates for a current block and selecting a motion vector predictor of the current block out of the motion vector predictor candidates, wherein the motion vector predictor candidates for the current block include a motion vector of a first candidate block which is first searched for as an available block out of left neighboring blocks of the current block and a motion vector of a second candidate block which is first searched for as an available block out of upper neighboring blocks of the current block.
Abstract:
A method and an apparatus of decoding a video signal are provided. The present invention includes the steps of parsing first coding information indicating whether a residual data of an image block in the enhanced layer is predicted from a corresponding block in the base layer, from the bitstream of the enhanced layer, and decoding the video signal based on the first coding information. And, the step of parsing includes the step of performing modeling of the first coding information based on second coding information indicating whether prediction information of the corresponding block in the base layer is used to decode the image block in the enhanced layer. Accordingly, the present invention raises efficiency of video signal processing by enabling a decoder to derive information on a prediction mode of a current block in a decoder instead of transferring the information to the decoder.
Abstract:
A method for context-modeling coding information of a video signal for compressing or decompressing the coding information is provided. An initial value of a function for probability coding of coding information of a video signal of an enhanced layer is determined based on coding information of a video signal of a base layer.
Abstract:
The present invention includes determining a motion vector candidate set of a current block including a plurality of motion vector candidates, obtaining motion vector indication information of the current block from a video signal, extracting a motion vector candidate corresponding to the motion vector indication information from the motion vector candidate set, determining a predicted motion vector of the current block based on the extracted motion vector candidate, and performing motion compensation on the current block based on the predicted motion vector.
Abstract:
The present invention relates to a video signal decoding method for adding an intra prediction mode as a sub-macroblock type to prediction of a macroblock in coding a video signal. The present invention includes obtaining a macroblock type, checking whether a macroblock includes a intra prediction coded sub-macroblock and a inter prediction coded sub-macroblock when a macroblock includes a plurality of coded sub-macroblocks according the macroblock type, when the macroblock includes the intra prediction coded sub-macroblock and the inter prediction coded sub-macroblock, obtaining prediction mode flag information indicating whether the sub-macroblock is the intra prediction coded or the inter prediction coded, when the sub-macroblock is the intra prediction coded based on the prediction mode flag information, obtaining prediction direction information from a block adjacent to the sub-macroblock and a prediction value of the sub-macroblock based on the prediction direction information, and when the sub-macroblock is inter prediction coded based on the prediction mode flag information, obtaining motion information from the block adjacent to the sub-macroblock and a prediction value of the sub-macroblock based on the motion information. Accordingly, the present invention is able to raise coding efficiency of video signal by adding an intra prediction mode as a sub-macroblock type in predicting a macroblock.
Abstract:
Disclosed are an intra prediction method of a chrominance block using a luminance sample and an apparatus using the same. An image decoding method comprises the steps of: calculating an intra prediction mode of a chrominance block on the basis of an LM mapping table when the chrominance block uses an LM; and generating a prediction block for the chrominance block on the basis of the calculated intra prediction mode of the chrominance block. When intra prediction mode information of chrominance blocks are decoded, mutually different tables are used depending on whether or not an LM is used, so that encoding and decoding can be performed without an unnecessary waste of bits.
Abstract:
The present invention relates to a method for decoding a video signal, comprising the steps of: acquiring a transform size flag of the current macroblock from a video signal; checking the number of non-zero transform coefficients at each pixel position in a first transform block which corresponds to the transform size flag; changing a scan order of the first transform block by prioritizing the position of the pixel having the greatest number of the non-zero transform coefficients in the first transform block; determining the number of the non-zero transform coefficients at each pixel position in a second transform block, and setting the changed scan order of the first transform block as an initialized scan order of the second transform block; adding the number of the non-zero transform coefficients at each pixel position in the first transform block and the number of the non-zero transform coefficients at each pixel position in the second transform block, and changing the scan order of the second transform block by prioritizing the position of the pixel having the greatest number of the non-zero transform coefficients; and decoding the transform coefficients arranged in the scan order changed in the previous step, wherein the first transform block and the second transform block have sizes corresponding to the transform size flag, and are contained in the current macroblock.