摘要:
A video coding and decoding method using a weighted prediction and an apparatus for the same are provided. The video coding method includes generating a predicted image for a present block; generating a weighted prediction factor which is a scaling factor of the predicted image that minimizes the difference between the present block and the predicted image; generating a weighted prediction image by multiplying the predicted image by the weighted prediction factor; and coding a residual signal generated by subtracting the weighted prediction image from the present block.
摘要:
Methods and apparatuses for encoding and decoding based on intra prediction. The method of encoding an image based on intra prediction comprises dividing a current block into a plurality of sub blocks so that a plurality of unit blocks adjacent to each other are included in one of the sub blocks based on an intra prediction direction of each of the unit blocks included in the current block, and performing intra prediction encoding on each of the sub blocks so that only information about one intra prediction direction is encoded in each of the sub blocks.
摘要:
An encoding method and apparatus and a decoding method and apparatus for determining a motion vector of a current block based on a motion vector of at least one previously-encoded or previously-decoded block are provided. The decoding method includes: decoding information regarding a prediction direction from among a first direction, a second direction, and bi-directions, and information regarding pixel values of the current block; determining the prediction direction in which the current block is to be predicted, based on the decoded information regarding the prediction direction, and determining a motion vector for predicting the current block in the determined prediction direction; and restoring the current block, based on the determined motion vector and the decoded information regarding the pixel values, wherein the first direction is a direction from a current picture to a previous picture, and the second direction is a direction from the current picture to a subsequent picture.
摘要:
Provided are methods and apparatuses for encoding and decoding a motion vector. The method of encoding the motion vector includes: selecting, as a mode of encoding information about a motion vector predictor of the current block, a first mode in which information indicating the motion vector predictor from among at least one motion vector predictor is encoded or a second mode in which information indicating generation of the motion vector predictor based on blocks or pixels included in a previously encoded area adjacent to the current block is encoded; determining the motion vector predictor of the current block according to the selected mode and encoding the information about the motion vector predictor of the current block; and encoding a difference vector between the motion vector of the current block and the motion vector predictor of the current block.
摘要:
Provided are a method and apparatus for encoding an image capable of improving compression efficiency of the image by compensating for a loss due to quantization of a residual block in the frequency domain, and a method and apparatus for decoding the image. The method of encoding an image includes: generating a prediction macro block for a current macro block; generating a first residual block which is a difference between the prediction macro block and the current macro block; generating a compensation residual block by compensating for a quantization loss of the first residual block in the frequency domain; compensating for the prediction macro block by adding the compensation residual block and the prediction macro block.
摘要:
A method and apparatus are provided for reducing the inter-layer redundancy of a difference signal obtained from an intra-prediction when coding a video using multi-layer structure supporting intra-prediction. The method includes obtaining a first difference block between a block of a first layer and a first prediction block which is used to perform an intra-prediction on the block, obtaining a second difference block between a block of a second layer corresponding to the block of the first layer and a second prediction block which is used to perform an intra-prediction on the block, and obtaining a final difference block between the first difference block and the second difference block.
摘要:
A method and apparatus are provided for improving the compression efficiency of motion vectors of an unsynchronized picture by efficiently predicting the motion vectors using motion vectors of a lower layer. The method compresses motion vectors of an unsynchronized picture belonging to a current layer in a video encoder based on a multilayer having at least the current layer and a lower layer of the current layer. The method includes selecting a base picture for the unsynchronized picture, generating a predicted motion vector of the current layer from a motion vector of the base picture, subtracting the predicted motion vector from a motion vector of the unsynchronized picture, and encoding the result of subtraction.
摘要:
A method and apparatus for extracting a higher quality video stream for a given bit-rate by replacing a specific frame by a base layer frame at a predecoder are provided. A predecoding method performed by the predecoder includes selecting a mode by determining frames to be skipped according to a predetermined criterion among frames located at positions where the base layer exists, and extracting a portion of the bitstream according to the selected mode and extraction conditions.
摘要:
Disclosed are a method and an apparatus for realizing signal to noise ratio (SNR) scalability in a video stream server in order to transmit a video stream in a variable network environment. An apparatus for adapting a bitrate of a coded scalable bit-stream based on multi-layers to a variable network environment, comprising a bit-stream parsing unit to parse an input bit-stream, a pre-decoding condition determining unit to determine a target transmission bitrate according to the variable network environment, a pre-decoding unit to skip at least one frame among the frames included in the parsed bit-stream according to the determined target transmission bitrate, and a bit-stream transmission unit to transmit to a client device the bit-stream that has been restructured due to frame skipping.
摘要:
A method of encoding flags, a method of decoding flags and an apparatus thereof, in which flag encoding and decoding can be efficiently performed by using spatial correlation between various flags included a plurality of blocks are provided. The method includes collecting flag values respectively allocated to groups of the plurality of blocks according to spatial correlation of blocks to create a flag bit-string, dividing the flag bit-string into a plurality of divided bit-strings using a group size, setting a pattern bit indicating whether all bits included in the divided bit-strings are 0 or not, and performing entropy coding on the divided bit-strings according to the set pattern bit.