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:
A method and apparatus for encoding and decoding an image. The method of encoding an image includes generating a prediction block of a current block of a current image by performing continuous motion estimation, and encoding the current block based on the generated prediction block. The current block can be more precisely predicted so that the compression rate of image encoding is improved.
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 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:
A method and apparatus for intraprediction encoding/decoding is provided. The method includes performing image inpainting based on pixels included in a previously encoded region of a current picture among pixels that are adjacent to a boundary between a current block and the previously encoded region of the current picture in order to predict the current block, and performing prediction encoding on the current block using the prediction result. Thus, a new intraprediction mode in which the current block can be accurately predicted can be provided.
摘要:
A method and apparatus for encoding and decoding a video signal on a group basis is disclosed, in which blocks constituting a multi-layer video signal are coded. The method includes grouping every two or more blocks having symbols that have a value identical to a predetermined value, generating group-based symbols each indicating information about the grouped blocks, and coding the group-based symbols.
摘要:
A method and apparatus for efficiently encoding diverse flags being used in a multilayer-based scalable video codec, based on an inter-layer correlation. The encoding method includes judging whether flags of a current layer included in a specified unit area are all equal to flags of a base layer, setting a specified prediction flag according to the result of judgment, and if it is judged that the flags of the current layer are equal to the flags of the base layer, skipping the flags of the current layer and inserting the flags of the base layer and the prediction flag into a bitstream.
摘要:
Methods and apparatuses for entropy encoding and decoding Fine-granularity Scalability (FGS) layer video data are provided. The encoding method includes extracting residual data between a first block and a second block in a layer lower than the FGS layer corresponding to the first block; obtaining transform coefficients; dividing the transform coefficients in the first block into at least two subblocks; calculating the length of a prefix of first coefficients in the subblocks; and combining the prefix with a suffix used to distinguish the first coefficients; and VLC encoding the first coefficients. The encoding apparatus includes a subblock divider, a prefix generator, and a significant coefficient encoding unit. The decoding method includes calculating a range of a transform coefficient using a length of a prefix of the transform coefficient; extracting a value of the transform coefficient; VLC decoding the value; and combining first and second subblocks having the decoded coefficients.
摘要:
A multi-layered video encoding method is provided wherein motion estimation is performed by using one of two frames of a lower layer temporally closest to an unsynchronized frame of a current layer as a reference frame. A virtual base layer frame at the same temporal location as that of the unsynchronized frame is generated using a motion vector obtained as a result of the motion estimation and the reference frame. The generated virtual base layer frame is subtracted from the unsynchronized frame to generate a difference, and the difference is encoded.