A method for in-loop sample offset filtering in a video decoder is disclosed. The method includes obtaining at least one statistical property associated with reconstructed samples of at least a first color component in a current reconstructed data block of a video stream, selecting a target sample offset filter among a plurality of sample offset filters based on the at least one statistical property, the target sample offset filter comprising a nonlinear mapping between sample delta measures and sample offset values, and filtering a current sample in a second color component of the current reconstructed data block using the target sample offset filter and reference samples in a third color component of the current reconstructed data block to generate a filtered reconstructed sample of the current sample.

Aspects of the disclosure provide a method and an apparatus for video decoding. The apparatus includes processing circuitry that decodes prediction information of one or more blocks including a current block from a coded video bitstream. The prediction information indicates that local illumination compensation (LIC) is applied to the one or more blocks and includes LIC information of the one or more blocks. The processing circuitry determines a final scaling factor α.sub.f1 and a final offset β.sub.f1 of a first subblock in the current block based on the LIC information. The processing circuitry determines an updated first predictor subblock in a predictor corresponding to the current block based on the final scaling factor α.sub.f1, the final offset β.sub.f1, and the first predictor subblock. An updated value of a first sample in the first predictor subblock is equal to α.sub.f1×p.sub.i1+β.sub.f1.Math.p.sub.i1 is a value of the first sample.

Aspects of the disclosure provide a method and an apparatus for video decoding. The apparatus includes processing circuitry that decodes prediction information of one or more blocks including a current block from a coded video bitstream. The prediction information indicates that local illumination compensation (LIC) is applied to the one or more blocks and includes LIC information of the one or more blocks. The processing circuitry determines a final scaling factor α.sub.f1 and a final offset β.sub.f1 of a first subblock in the current block based on the LIC information. The processing circuitry determines an updated first predictor subblock in a predictor corresponding to the current block based on the final scaling factor α.sub.f1, the final offset β.sub.f1, and the first predictor subblock. An updated value of a first sample in the first predictor subblock is equal to α.sub.f1×p.sub.i1+β.sub.f1.Math.p.sub.i1 is a value of the first sample.

A method of processing an image divided into a plurality of pixel blocks which are processed according to a processing sequence is provided, which comprises, for a current pixel block: determining an application area consisting of a set of pixels in blocks preceding the current block in the processing sequence, for each pixel of the application area, computing a gradient representing a directional change of an intensity at the pixel, and selecting, based on at least one of the computed gradients, an intra prediction video coding mode among a plurality of intra prediction video coding modes usable for encoding and/or decoding the current block.

The present invention relates to an image information encoding and decoding method and a device for same. One embodiment of an image information encoding method according to the present invention, as an image information encoding method according to another embodiment of the present invention, includes the steps of: generating a restore block; applying a deblocking filter on the restore block; applying a Sample Adaptive Offset (SAO) on the restore block having the deblocking filter applied thereon; and transmitting information on the SAO application. During the applying of the SAO, the SAO is applied to chroma pixels, and during the transmitting of the information, in addition to information on whether the SAO is applied on the chroma pixels, at least one of area information, division information on the SAO coverage area, SAO type information, and SAO offset information is transmitted.

The present invention relates to an image information encoding and decoding method and a device for same. One embodiment of an image information encoding method according to the present invention, as an image information encoding method according to another embodiment of the present invention, includes the steps of: generating a restore block; applying a deblocking filter on the restore block; applying a Sample Adaptive Offset (SAO) on the restore block having the deblocking filter applied thereon; and transmitting information on the SAO application. During the applying of the SAO, the SAO is applied to chroma pixels, and during the transmitting of the information, in addition to information on whether the SAO is applied on the chroma pixels, at least one of area information, division information on the SAO coverage area, SAO type information, and SAO offset information is transmitted.

Systems and methods of encoding display data include performing a part of a first predetermined transform algorithm on at least a first part of a first frame of display data, and analyzing a light level to determine whether a different transform algorithm would be more suitable for encoding a second part of the first frame of the display data. If it is determined that a different transform algorithm would be more suitable for encoding, the second part of the first frame of the display data is encoded using the different transform algorithm to generate an encoded first frame. If it is determined that a different transform algorithm would not be more suitable for encoding, the second part of the first frame of the display data is encoded using the first predetermined transform algorithm to generate the encoded first frame.

The present disclosure provides a method and an apparatus for coding a video, a device and a medium. An estimated quantization parameter of a target picture in a target GOP is determined. An inter-picture change degree of the target GOP is determined. A propagation ratio of a target picture block to a reference picture block in the target picture is determined based on the estimated quantization parameter of the target picture and the inter-picture change degree. The video is coded based on the propagation ratio.

A video decoder is configured to determine, for a current block of video data, a classifier from a plurality of available classifiers for the current block, wherein each classifier of the plurality of available classifiers defines a process for calculating a class index; determine a class index based on the classifier and one or more sample values of the current block; select a filter from a set of filters based on the class index; and apply the filter to the current block.

An image encoding apparatus comprises a controller configured to select, from a set of prediction directions, a set of candidate prediction directions as a subset of the set of prediction directions, for a current image region of a current image in dependence upon one or more properties of a group of reference samples of the current image applicable to the current image region; and an intra-image predictor configured to predict samples of the current image region with respect to one or more of the group of reference samples of the same image according to a prediction direction between the current sample and a reference position amongst the reference samples; in which the intra-image predictor is configured to select the prediction direction for the current image region from the set of candidate prediction directions.