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: acquiring offset type information of a current block; determining a neighboring sample of a current reconstruction sample of the current block according to an edge direction when the offset type information of the current block indicates an edge type; determining an offset category of the current reconstruction sample based on a sample value gradient between a sample value of the current reconstruction sample and a sample value of the neighboring sample and a difference in the sample value gradient; and applying, from among offsets acquired from a bitstream, an offset according to the determined offset category to the current reconstruction sample.
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 is a video encoding method including determining a reference layer image from among base layer images, wherein the reference layer image corresponds to an enhancement layer image; determining a phase shift between pixels of the enhancement layer image and the reference layer image, according to a scaling factor between the enhancement layer image and the reference layer image and a color format of the enhancement layer; selecting at least one filter coefficient set corresponding to the phase shift, from filter coefficient data including filter coefficient sets; generating an up-sampled reference layer image by extending a resolution of the reference layer image according to the scaling factor by performing interpolation filtering on the reference layer image by using the filter coefficient set; obtaining a prediction error between the up-sampled reference layer image and the enhancement layer image; generating an enhancement layer bitstream including the prediction error and a scalable codec; and generating a base layer bitstream by encoding the base layer images.
Abstract:
Provided are scalable video encoding and decoding methods for optimization of a memory bandwidth and a computational quantity when inter-layer prediction is performed.The scalable video encoding method includes determining a reference layer image from among base layer images so as to perform inter-layer prediction on an enhancement layer image, determining, using the enhancement layer image, not to perform inter prediction on enhancement layer images when an upsampled reference layer image is determined by performing inter-layer (IL) interpolation filtering on the reference layer image, and encoding a residue component between the upsampled reference layer image and the enhancement layer image.
Abstract:
Provided are a method of interpolating an image by determining interpolation filter coefficients, and an apparatus for performing the same. The method includes: differently selecting an interpolation filter, from among interpolation filters for generating at least one sub-pel-unit pixel value located between integer-pel-unit pixels, based on a sub-pel-unit interpolation location and a smoothness; and generating the at least one sub-pel-unit pixel value by interpolating, using the selected interpolation filter, pixel values of the integer-pel-unit pixels.
Abstract:
A sub-pel-unit image interpolation method using a transformation-based interpolation filter includes, selecting, based on a sub-pel-unit interpolation location in a region supported by a plurality of interpolation filters for generating at least one sub-pel-unit pixel value located between integer-pel-unit pixels, one of a symmetric interpolation filter and an asymmetric interpolation filter from among the plurality of interpolation filters; and using the selected interpolation filter to generate the at least one sub-pel-unit pixel value by interpolating the integer-pel-unit pixels.
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:
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:
Provided are a video encoding method of adjusting a range of encoded output data to adjust a bit depth during restoring of encoded samples, and a video decoding method of substantially preventing overflow from occurring in output data in operations of a decoding process. The video decoding method includes parsing and restoring quantized transformation coefficients in units of blocks of an image from a received bitstream, restoring transformation coefficients by performing inverse quantization on the quantized transformation coefficients, and restoring samples by performing one-dimensional (1D) inverse transformation and inverse scaling on the quantized transformation coefficients. At least one from among the transformation coefficients and the samples has a predetermined bit depth or less.