Sk Telecom Company, Ltd.

Chanwon Seo

Byeungwoo Jeon

Yunglyul Lee

Haekwang Kim

Joohee Moon

Jeongyeon Lim

Jongki Han

Jinhan Song

Hyoungmee Park

Daeyeon Kim

Sunyeon Kim

Min Jae Kim

Gyumin Lee

Jaehoon Choi

Joong Gunn Park

A video decoding apparatus includes: a decoder to determine a size of a minimum block unit among block units in which quantization parameter information is decoded from a bitstream, determine a current block to be decoded by dividing a block larger than 16&#xd7;16 into one or more blocks, decode, from the bitstream, a skip information and the motion information for deriving the motion vector of the current block without decoding information on residual signals of the current block, and decode, from the bitstream, prediction information of the current block and quantized transform coefficients of the current block; and a video reconstructor to determine the motion vector of the current block using the decoded motion information, reconstruct residual signals from the quantized transform coefficients by inversely quantizing the quantized transform coefficients using a quantization parameter, and reconstruct the current block based on the prediction information and the reconstructed residual signals.

Video encoding/decoding apparatus and method

A video encoding/decoding apparatus and method are disclosed. The video encoding/decoding apparatus includes: a video encoder for encoding a differential value between a quantization parameter value of a macroblock of a video and a quantization parameter value of a subblock in an extended macroblock based on additional information on the macroblock and the subblock; and a video decoder for reconstructing a differential value of a quantization parameter encoded by the video encoder, reconstructing a residual block based on a reconstructed differential value of the quantization parameter, and reconstructing the video based on the residual block reconstructed.

Image encoding/decoding device and method

A video encoding method using inter-prediction, includes: encoding a first picture, wherein the first picture serves as a random access picture and is encoded without referring to a reference picture which has already encoded and then decoded; inter-prediction encoding a block included in a second picture, which is encoded after the first picture and displayed before the first picture, by using a plurality of reference pictures; generating reference picture information representing one or more past pictures which are encoded before the first picture and are used as reference pictures for encoding the second picture; and transmitting the encoded first picture and the encoded second pictures and the reference picture information, wherein, when the one or more past pictures are used as the reference pictures for encoding the second picture, the one or more past pictures are deleted from a memory after encoding at least the second picture.

Inter-prediction method and video encoding/decoding method using the inter-prediction method

The present disclosure provides a method and apparatus for encoding and decoding a video. In particular, the apparatus for encoding a video includes an offset calculator to calculate an offset between pixels of neighboring blocks corresponding to an intra prediction direction; and a prediction unit to adaptively perform an intra prediction on a current block in consideration of the calculated offset so as to generate a predicted block, and to intra-predictively encode the current block.

Method and apparatus for encoding/decoding video using bidirectional intra prediction

A video encoding apparatus includes: a parameter calculator to calculate a brightness compensation parameter based on one or more first pixels adjacent to a current block and one or more second pixels adjacent to a motion prediction block obtained by using a prediction motion vector, the one or more second pixels being located in locations corresponding to the one or more first pixels; a target pixel selector to select one or more target pixels for a brightness compensation from pixels in a prediction block determined by a motion vector of the current block, by using pixels adjacent to the motion prediction block; and a predictive encoder to generate a compensated prediction block of the prediction block by applying the brightness compensation parameter to the selected one or more target pixels and to perform a predictive encoding on the generated compensated prediction block.

Apparatus and method for coding and decoding image

A video encoding method using inter-prediction, includes: encoding information indicating whether a first picture is a picture which allows a second picture preceding the first picture in a display order to refer to at least one picture encoded before the first picture, wherein the first picture serves as a random access picture; encoding the first picture without referring to a reference picture which has already encoded; and when the first picture is a picture which allows the second picture to refer to the at least one picture encoded before the first picture, inter-prediction encoding, after encoding the first picture, the second picture by using at least one reference picture encoded before the first picture, and encoding reference picture information used for encoding the second picture, wherein the at least one reference picture encoded before the first picture is not deleted from a memory until the second picture are encoded.

The present disclosure provides a motion vector encoding/decoding method and apparatus using a motion vector resolution combination, and an image encoding/decoding method and apparatus using the same. A motion vector encoding apparatus include: an encoding cost calculator for calculating an encoding cost according to a motion vector resolution for each motion vector resolution combination including one or more motion vector resolutions; a resolution combination determiner for selecting a motion vector resolution combination by using the encoding cost calculated for each motion vector resolution combination; and a motion information encoder for outputting encoded motion vector data generated by encoding a motion vector determined according to the motion vector resolution combination selected, as a bitstream. Accordingly, an efficient motion vector resolution combination is selected adaptively and a motion vector is determined and decoded based on the motion vector resolution combination, thus making it possible to improve compression efficiency.

Motion vector encoding/decoding method and apparatus using a motion vector resolution combination, and image encoding/decoding method and apparatus using same

A video decoding method using inter-prediction, includes: identifying, based on information included in a bitstream, whether a first picture is a picture which allows a second picture preceding the first picture in a display order to refer to at least one picture decoded before the first picture, the first picture serving as a random access picture; decoding the first picture without referring to a reference picture which has already decoded; and when the first picture is a picture which allows the second picture to refer to the at least one picture decoded before the first picture, inter-prediction decoding, after decoding the first picture, the second picture by using at least one reference picture which is decoded before the first picture depending on reference picture information of the second picture.

A video decoding method using inter-prediction, includes: decoding a first picture, wherein the first picture serves as a random access picture and is decoded without referring to a reference picture which has already decoded; and decoding a block, by using an inter-prediction, included in a second picture, which is decoded after the first picture and displayed before the first picture, by using a plurality of reference pictures, wherein the decoding of the block included in the second picture is performed based on reference picture information representing one or more past pictures which are decoded before the first picture and are used as reference pictures for decoding the second picture, and wherein when the one or more past pictures are used for decoding the second picture, the one or more past pictures are deleted from a memory after decoding at least the second picture.

A video decoding method includes: decoding a skip information indicating whether or not a current block to be decoded is a skip block; when the skip information indicates that the current block is the skip block, decoding motion information of the current block, determining a motion vector of the current block, and reconstructing the current block directly from a predicted block, without decoding information on residual signals of the current block; and when the skip information indicates that the current block is not the skip block, decoding prediction information of the current block from the bitstream, decoding information on a quantization parameter and transform coefficients which correspond to the current block, when at least one of the transform coefficients is not zero, reconstructing residual signals from the transform coefficients and reconstructing the current block based on the prediction information and the reconstructed residual signals.

Video decoding method using skip information

A video encoding/decoding apparatus includes: a video encoder for dividing coding unit block into combination of subblocks of codable size, determining combination of inter blocks and intra blocks with respect to each subblock, determining encoding order of intra encoding blocks within coding unit considering referencing possibility of peripheral pixel values of current block to be intra-prediction encoded, bi-directional intra prediction encoding the current block in determined encoding order, and transmitting encoding mode/size information of subblocks after locating encoding mode/size information in front of a syntax of the coding unit; and a video decoder for restoring encoding mode/size information of subblocks within the coding unit by decoding encoded data, reconstructing inter prediction encoded blocks, based on restored encoding mode information, and determining decoding order of intra prediction mode blocks according to encoding mode/size information of each subblock within coding unit, and conditions on referencing possibility of peripheral blocks of coding unit.

Image coding/decoding device using coding block in which intra block and inter block are mixed, and method thereof

An inter-prediction method and a video encoding/decoding method using the inter-prediction method are disclosed. The video encoding method using inter-prediction includes: encoding a first picture that serves as a reference for random access; inter-prediction encoding a block included in a second picture, which is displayed before the first picture, by using a plurality of reference pictures; generating reference picture information representing whether a past picture, which is displayed before the second picture, is used as a reference picture for encoding the second picture; and transmitting the encoded first and second pictures and the reference picture information.

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Seoul, South Korea

Chanwon Seo