Abstract:
Provided are a method and apparatus for encoding or decoding a coding unit on an outline of a picture. An image decoding method and apparatus according to an embodiment determine whether a current coding unit extends across an outline of a picture, by comparing a location of the current coding unit in the picture to at least one of a width and a height of the picture, split the current coding unit in at least one direction into a plurality of coding units based on a shape of the current coding unit upon determining that the current coding unit extends across the outline of the picture, obtain block shape information and split type information of the current coding unit from a bitstream and split the current coding unit into a plurality of coding units based on the block shape information and the split type information upon determining that the current coding unit does not extend across the outline of the picture, and decode a coding unit that is no longer split among the plurality of coding units.
Abstract:
Provided are methods and apparatuses for encoding and decoding an image. Method of encoding includes: determining a maximum size of a buffer to decode each image frame by a decoder, a number of image frames to be reordered, and latency information of an image frame having a largest difference between an encoding order and a display order from among image frames that form an image sequence, based on an encoding order the image frames that form the image sequence, an encoding order of reference frames referred to by the image frames, a display order of the image frames, and a display order of the reference frames; and adding, to a mandatory sequence parameter set, a first syntax indicating the maximum size of the buffer, a second syntax indicating the number of image frames to be reordered, and a third syntax indicating the latency information.
Abstract:
Provided is a video decoding method including obtaining, from a bitstream, information about a prediction mode of a current block; when the prediction mode of the current block is an intra mode, obtaining information about an intra prediction mode of the current block; obtaining a predicted sample value of the current block by using at least one sample that is from among samples included in an adjacent reference region of a plurality of lines and is located, from the current block, in an intra prediction direction indicated by an intra prediction mode. The adjacent reference region of the plurality of lines may include a plurality of lines that are in a vertical direction and located at a left side of the current block, or a plurality of lines that are in a horizontal direction and located at an upper side of the current block.
Abstract:
Provided are methods and apparatuses for encoding and decoding an image. The method of encoding includes: determining a maximum size of a buffer to decode each image frame by a decoder, a number of image frames to be reordered, and latency information of an image frame having a largest difference between an encoding order and a display order from among image frames that form an image sequence, based on an encoding order the image frames that form the image sequence, an encoding order of reference frames referred to by the image frames, a display order of the image frames, and a display order of the reference frames; and adding, to a mandatory sequence parameter set, a first syntax indicating the maximum size of the buffer, a second syntax indicating the number of image frames to be reordered, and a third syntax indicating the latency information.
Abstract:
An video decoding apparatus including a parser which obtains bit strings corresponding to current transformation coefficient level information by arithmetic decoding a bitstream based on a context model; a parameter determiner which determines a current binarization parameter by updating or maintaining a previous binarization parameter based on a comparison of a threshold and a size of a previous transformation coefficient; a syntax element restorer which obtains the current transformation coefficient level information by performing de-binarization of the bit strings using the determined current binarization parameter and generates a size of a current transformation coefficient using the current transformation coefficient level information, wherein the current binarization parameter has a value equal to or smaller than a predetermined value.
Abstract:
Provided are multilayer video encoding/decoding methods. The multilayer video decoding method includes obtaining, from a bitstream, instantaneous decoder refresh (IDR) alignment information specifying whether at least one intra random access point (IRAP) picture for a random access and comprised in a same access unit is limited to being an IDR picture; and reconstructing a multilayer video by decoding encoded data by using the IDR alignment information.
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:
Methods and apparatuses for decoding and encoding video are provided. A method includes obtaining bit strings corresponding to current transformation coefficient level information by arithmetic decoding a bitstream based on a context model that indicates a probability as to whether a bit from a bit string is a one or a zero, updating or maintaining a previous binarization parameter based on a comparison of a predetermined value and a size of a previous transformation coefficient, obtaining the current transformation coefficient level information by performing de-binarization of the bit strings using the determined current binarization parameter, and generating a size of a current transformation coefficient using the current transformation coefficient level information.
Abstract:
A video prediction encoding method including setting a default number of reference images assigned to a list combination (LC) reference list in units of pictures, the LC reference list including at least one reference image from among a plurality of reference images included in reference lists L0 and L1 which are information about lists of reference images for prediction encoding a current image that is a B type slice; and prediction encoding the current image by using the determined LC reference list including at least one reference image from among the plurality of reference images included in the reference lists L0 and L1, based on the default number.
Abstract:
Provided are a method and device for encoding or decoding an image by using a block map. In the method and device for decoding an image according to an embodiment set forth herein, a bitstream of an encoded image is received, one or more blocks in a picture are determined using split information obtained from the bitstream, a block map indicating whether or not a previous block among the one or more blocks has been decoded is determined, a neighboring region which is available to be referred to for a current block to be decoded in a certain scan order among the one or more blocks is determined, and the current block is decoded based on the neighboring region which is available to be referred to.