摘要:
Context-based adaptive arithmetic coding and decoding methods and apparatuses with improved coding efficiency using the same are provided. The context-based adaptive arithmetic coding method includes resetting a context model for the given slice to a context model for a slice coded temporally before the given slice, arithmetically encoding a data symbol of the given slice using the reset context model, and updating the context model using a value of the data symbol. The context-based adaptive arithmetic decoding method includes resetting a context model for the given slice to a context model coded temporally before the given slice, arithmetically decoding a bitstream corresponding to the given slice using the reset context model to generate a data symbol of the given slice, and updating the context model using a value of the data symbol.
摘要:
A video encoding/decoding method and apparatus is disclosed that can efficiently compress/decompress motion vectors in a video codec including a hierarchical temporal level decomposition process. The video encoding method including a hierarchical temporal level decomposition process involves obtaining a predicted motion vector of a second frame, which exists at a present temporal level, from a first motion vector of a first frame that exists at a lower temporal level; obtaining a second motion vector of the second frame by performing a motion estimation in a predetermined motion search area using the predicted motion vector as a start point; and encoding the second frame using the obtained second motion vector.
摘要:
A video compression method, and more particularly, a prediction method for efficiently eliminating redundancy within a video frame, and a video compression method and an apparatus using the prediction method are provided. There is provided a method for encoding video based on a multi-layer structure, including performing intra-prediction on a current intra-block using images of neighboring intra-blocks of the current intra-block to obtain a prediction residual, performing prediction on the current intra-block using an image of a lower layer region corresponding to the current intra-block to obtain a prediction residual, selecting one of the two prediction residuals that offers higher coding efficiency, and encoding the selected prediction residual.
摘要:
A method and apparatus for increasing output picture quality at a decoding terminal by using a smoothing filter are provided. The video decoding method includes generating a residual frame from an input bitstream, performing wavelet-based upsampling on the residual frame, performing non-wavelet-based downsampling on the upsampled frame, and performing inverse temporal filtering on the downsampled frame.
摘要:
Video coding and decoding methods and video encoder and decoder are provided. The video encoding method includes determining one of inter predictive coding and intra predictive coding mode as a coding mode for each block in an input video frame, generating a predicted frame for the input video frame based on predicted blocks obtained according to the determined coding mode, and encoding the input video frame based on the predicted frame. When the intra predictive coding mode is determined as the coding mode, an intra basis block composed of representative values of a block is generated for a block and the intra basis block is interpolated to generate an intra predicted block for the block.
摘要:
A video encoder/decoder and method. The video coding method includes estimating a virtual frame, electing a reference frame from candidate frames including the virtual frame to remove temporal redundancy using the elected reference frame, coding a motion vector and predetermined information obtained in removing the temporal redundancy, and obtaining transform coefficients from the frames free from the temporal redundancy and quantizing the obtained transform coefficients to generate a bit-stream. The video decoding method includes receiving a bit-stream and parsing the received bit-stream to extract information on coded frames, inversely quantizing the information on the coded frames to obtain the transform coefficients, and performing inverse spatial transform of the obtained transform coefficients and inverse temporal transform by use of a reference frame including a virtual frame in inverse order to an order in which redundancy of the coded frames is removed and restoring the coded frames. As a result, it is possible to code the video at a higher compression rate.
摘要:
Disclosed is a scalable video coding algorithm. A method for video coding includes temporally filtering frames in the same sequence to a decoding sequence thereof to remove temporal redundancy, obtaining and quantizing transformation coefficients from frames whose temporal redundancy is removed, and generating bitstreams. A video encoder comprises a temporal transformation unit, a spatial transformation unit, a quantization unit and a bitstream generation unit to perform the method. A method for video decoding is basically reverse in sequence to the video coding. A video decoder extracts information necessary for video decoding by interpreting the received bitstream and decoding it. Thus, video streams may be generated by allowing a decoder to decode the generated bitstreams, while maintaining the temporal scalability on an encoder-side.
摘要:
A method and apparatus for encoding and decoding a motion vector of a current block. The method of encoding including: generating information about the motion vector based on a motion vector of a current block and a motion vector predictor of the current block by estimating the motion vector and determining a first motion vector predictor candidate from among a plurality of motion vector predictor candidates as the motion vector predictor based on a result of the estimating; and generating a virtual motion vector by using a second motion vector predictor candidate and the information about the motion vector, generating vector differences between the virtual motion vector and the plurality of motion vector predictor candidates, comparing the vector differences with the information about the motion vector, and selectively excluding the second motion vector predictor candidate according to the comparing.
摘要:
A method and apparatus for generating an optimized bitstream. In the method, a bitstream including first and second processing units is received. The video processing units are encoded to generate syntax data for syntax elements of the video processing units. The syntax data of the video processing units are grouped according to the type of syntax element, and the groups are arranged in a predetermined order to produce the optimized bitstream.
摘要:
A method and apparatus for encoding and decoding a video are provided. The method of encoding the video includes: determining whether a unidirectional motion estimation mode and a bidirectional motion estimation mode are to be used based on a size of a current prediction unit to be encoded, performing the motion estimation and the motion compensation on the current prediction unit according to the determining of whether the unidirectional motion estimation mode and the bidirectional motion estimation mode are to be used, determining an optimum motion estimation mode of the current prediction unit based on an encoding cost of the current prediction unit obtained through the performing of the motion estimation and the motion compensation, and encoding information indicating the determined optimum motion estimation mode based on the size of the current prediction unit.