Abstract: A video encoding method and apparatus, and a video decoding method and apparatus for generating a reconstructed image having a minimized error between an original image and the reconstructed image. The video decoding method accompanied by a sample adaptive offset (SAO) adjustment, the method includes: obtaining 5 slice SAO parameters with respect to a current slice from a slice header of a received bitstream; obtaining luma SAO use information for a luma component of the current slice and chroma SAO use information for chroma components thereof from among the slice SAO parameters; determining whether to perform a SAO operation on the luma component of 10 the current slice based on the obtained luma SAO use information; and equally determining whether to perform the SAO adjustment on a first chroma component and a second chroma component of the current slice based on the obtained chroma SAO use information.

Abstract: A video encoding method and apparatus and video decoding method and apparatus generate a restored image having a minimum error with respect to an original image based on offset merge information indicating whether offset parameters of a current block and at least one neighboring block from among blocks of video are identical.

Abstract: Provided are a method and apparatus for encoding a video signal and a method and apparatus for decoding a video signal. The method of encoding the video signal includes: determining an optimum scaling bit depth of the video signal in consideration of a maximum bit number of an intermediate value obtained during transformation of the video signal and a maximum bit precision of the video signal; scaling the video signal according to a local shift value corresponding to a difference between the determined optimum scaling bit depth and an original bit depth of the video signal; and transforming the scaled video signal.

Abstract: An image decoding method and apparatus according to an embodiment may extract, from a bitstream, a quantization coefficient generated through core transformation, secondary transformation, and quantization; generate an inverse-quantization coefficient by performing inverse quantization on the quantization coefficient; generate a secondary inverse-transformation coefficient by performing secondary inverse-transformation on a low frequency component of the inverse-quantization coefficient, the secondary inverse-transformation corresponding to the secondary transformation; and perform core inverse-transformation on the secondary inverse-transformation coefficient, the core inverse-transformation corresponding to the core transformation.

Abstract: A video decoding apparatus includes: a splitter configured to split an image into at least one block; a predictor configured to predict a current sample by using at least one of a value obtained by applying a first weight to a first sample predicted earlier than the current sample in a current block and being adjacent to the current sample in a horizontal direction and a value obtained by applying a first weight to a second sample predicted earlier than the current sample in the current block and being adjacent to the current sample in a vertical direction; and a decoder configured to decode the image by using a residual value of the current sample obtained from a bitstream and a prediction value of the current sample.

Abstract: A method of encoding a video is provided, the method includes: determining a filtering boundary on which deblocking filtering is to be performed based on at least one data unit from among a plurality of coding units that are hierarchically configured according to depths indicating a number of times at least one maximum coding unit is spatially spilt, and a plurality of prediction units and a plurality of transformation units respectively for prediction and transformation of the plurality of coding units, determining filtering strength at the filtering boundary based on a prediction mode of a coding unit to which pixels adjacent to the filtering belong from among the plurality of coding units, and transformation coefficient values of the pixels adjacent to the filtering boundary, and performing deblocking filtering on the filtering boundary based on the determined filtering strength.

Abstract: Provided are a method and apparatus of encoding a video by compensating for a pixel value and a method and apparatus of decoding a video by compensating for a pixel value. The method of encoding the video includes: encoding image data; decoding the encoded image data and generating a restored image by performing loop filtering on the decoded image data; determining a compensation value corresponding to errors between a predetermined group restored pixels in the restored image and corresponding original pixels, and a pixel group including a restored pixel to be compensated for by using the compensation value; and encoding the compensation value and transmitting the encoded compensation value and a bitstream of the encoded image data.

Abstract: Provided are a method and apparatus for encoding a video signal and a method and apparatus for decoding a video signal. The method of encoding the video signal includes: determining an optimum scaling bit depth of the video signal in consideration of a maximum bit number of an intermediate value obtained during transformation of the video signal and a maximum bit precision of the video signal; scaling the video signal according to a local shift value corresponding to a difference between the determined optimum scaling bit depth and an original bit depth of the video signal; and transforming the scaled video signal.

Abstract: Provided is a video decoding method including: determining a size of a block on which intra block copy prediction is to be performed, based on block size information obtained from a bitstream; comparing the determined size of the block with a size of a current block, and determining, based on a result of the comparing, whether the size of the current block falls within the determined size of the block; and performing intra block copy prediction on the current block when it is determined that the size of the current block falls within the determined size of the block.

Abstract: Provided are a method and apparatus for encoding a video signal and a method and apparatus for decoding a video signal. The method of encoding the video signal includes: determining an optimum scaling bit depth of the video signal in consideration of a maximum bit number of an intermediate value obtained during transformation of the video signal and a maximum bit precision of the video signal; scaling the video signal according to a local shift value corresponding to a difference between the determined optimum scaling bit depth and an original bit depth of the video signal; and transforming the scaled video signal.

Abstract: A video encoding method and apparatus, and a video decoding method and apparatus for generating a reconstructed image having a minimized error between an original image and the reconstructed image. The video decoding method accompanied by a sample adaptive offset (SAO) adjustment, the method includes: obtaining 5 slice SAO parameters with respect to a current slice from a slice header of a received bitstream; obtaining luma SAO use information for a luma component of the current slice and chroma SAO use information for chroma components thereof from among the slice SAO parameters; determining whether to perform a SAO operation on the luma component of 10 the current slice based on the obtained luma SAO use information; and equally determining whether to perform the SAO adjustment on a first chroma component and a second chroma component of the current slice based on the obtained chroma SAO use information.

Abstract: A method for decoding an image including performing intra prediction on a chrominance block according to whether the intra prediction mode of the chrominance block is equal to an intra prediction mode of a luminance block.

Abstract: A video encoding method and apparatus and video decoding method and apparatus generate a restored image having a minimum error with respect to an original image based on offset merge information indicating whether offset parameters of a current block and at least one neighboring block from among blocks of video are identical.

Abstract: Provided are scalable video encoding and decoding methods by using a de-noise filtering. The scalable video decoding method includes generating reconstructed base layer images from a base layer image stream; determining a reference picture list including at least one of a de-noise reconstructed base layer image obtained from an enhancement layer image stream and one of the reconstructed base layer images that corresponds to a current enhancement layer image; and reconstructing the current enhancement layer image based on a reference image that is included on the reference picture list.

Abstract: A method of encoding a video is provided, the method includes: determining a filtering boundary on which deblocking filtering is to be performed based on at least one data unit from among a plurality of coding units that are hierarchically configured according to depths indicating a number of times at least one maximum coding unit is spatially spilt, and a plurality of prediction units and a plurality of transformation units respectively for prediction and transformation of the plurality of coding units, determining filtering strength at the filtering boundary based on a prediction mode of a coding unit to which pixels adjacent to the filtering belong from among the plurality of coding units, and transformation coefficient values of the pixels adjacent to the filtering boundary, and performing deblocking filtering on the filtering boundary based on the determined filtering strength.

Abstract: Provided are a method and apparatus for encoding a video signal and a method and apparatus for decoding a video signal. The method of encoding the video signal includes: determining an optimum scaling bit depth of the video signal in consideration of a maximum bit number of an intermediate value obtained during transformation of the video signal and a maximum bit precision of the video signal; scaling the video signal according to a local shift value corresponding to a difference between the determined optimum scaling bit depth and an original bit depth of the video signal; and transforming the scaled video signal.

Abstract: The present disclosure relates to signaling of sample adaptive offset (SAO) parameters determined to minimize an error between an original image and a reconstructed image in video encoding and decoding operations. An SAO decoding method includes obtaining context-encoded leftward SAO merge information and context-encoded upward SAO merge information from a bitstream of a largest coding unit (MCU); obtaining SAO on/off information context-encoded with respect to each color component, from the bitstream; if the SAO on/off information indicates to perform SAO operation, obtaining absolute offset value information for each SAO category bypass-encoded with respect to each color component, from the bitstream; and obtaining one of band position information and edge class information bypass-encoded with respect to each color component, from the bitstream.

Abstract: Provided is a video decoding method including obtaining, from a bitstream, upsampling phase set information indicating whether a phase of samples comprised in a current layer is adjusted; when the phase is adjusted according to the upsampling phase set information, obtaining a luma vertical phase difference, a luma horizontal phase difference, a chroma vertical phase difference, and a chroma horizontal phase difference from the bitstream; and determining a prediction picture of the current layer by upsampling a reference layer based on the luma vertical phase difference, the luma horizontal phase difference, the chroma vertical phase difference, and the chroma horizontal phase difference, wherein a phase of luma samples comprised in the prediction picture is adjusted according to the luma vertical phase difference and the luma horizontal phase difference, a phase of chroma samples comprised in the prediction picture is adjusted according to the chroma vertical phase difference and the chroma horizontal phase

Abstract: A video decoding method includes determining, from among a first sample and a second sample with different color components, at least one second sample that is used to correct a value of the first sample; determining a filter parameter set based on a band including the value of the first sample, wherein the band is from among a plurality of bands determined by dividing a total range of sample values into signaled intervals or predetermined intervals; and filtering a value of the at least one second sample by using the determined filter parameter set and correcting the value of the first sample by using a value obtained by the filtering, wherein the first sample is any one of a luma sample and a chroma sample, and the second sample is any one of the luma sample and the chroma sample that is not the first sample.

Abstract: Provided is a method of decoding a video according to an embodiment, the method including determining at least one processing block for splitting the video; determining an order of determining at least one largest coding unit in the at least one processing block; determining at least one largest coding unit on the basis of the determined order; and decoding the determined at least one largest coding unit, wherein the order is one of a plurality of orders for determining a largest coding unit.