Nippon Telegraph and Telephone Corporation

Bell Communications Research, Inc.

Nippon Telephone and Telegraph Corporation

Hirohisa Jozawa

Seishi Takamura

Kazuto Kamikura

Atsushi Shimizu

Hiroshi Watanabe

Yukihiro Bandoh

Shohei Matsuo

Atsushi Sagata

Masaaki Matsumura

Sharad Singhal

Regions based on which an interpolation method of a fractional-accuracy pixel is switched are optimized, and the interpolation method is switched for each of the divided regions, thereby reducing residual energy of inter-frame prediction with motion compensation. A video encoding apparatus is provided with: an encoding information acquiring unit which acquires encoding information for each block; a region classification unit which performs a region classification on a block-by-block basis in accordance with the encoding information; a divided region redefinition processing unit which shifts a region dividing line in a horizontal direction, a region dividing line in a vertical direction, or both the region dividing line in the horizontal direction and the region dividing line in the vertical direction based on a result of the region classification, and determines a region dividing line with which density of blocks belonging to a particular region classification is greater than or equal to a predetermined threshold value; an interpolation method switching unit which switches an interpolation method of a fractional-accuracy pixel for each of divided regions divided by the region dividing line; an interpolation performing unit which performs interpolation of the fractional-accuracy pixel for each of the divided regions; a picture encoding unit which encodes a picture using inter-frame prediction with motion compensation of fractional-accuracy for an interpolated picture; and a region classification information encoding unit which encodes information on the region classification.

Video encoding method, video decoding method, video encoding apparatus, video decoding apparatus, and programs thereof

A video encoding device uses motion-compensated inter-frame prediction by dividing an image into blocks, each block a predetermined size, designating a first component value of a plurality of component values of a motion vector (MV) between an encoding target block and a neighboring block, designating a second component value, and encoding each first and second component values; a first component encoding means encodes a difference value of a first component and a second component encoding means, which obtains a probability of occurrence of a candidate value for the second component value of the MV of the encoding target block, based on a difference value between the first component value of the neighboring block MV and the first component value of the encoding target block MV and the second component value of the neighboring block MV, specifies a codeword of the second component value, encoding it based on the occurrence probability.

Video encoding device, video decoding device, video encoding method, video decoding method, and non-transitory computer-readable recording media that use similarity between components of motion vector

The prediction error energy in inter-frame prediction with motion compensation is reduced and the coding efficiency is improved. A video encoding method using fractional-accuracy motion compensation includes: a step of generating multiple weighted filter coefficients from multiple interpolation filter sets using weight parameters which designate weight values of interpolation filter coefficients; a step of selecting weighted filter coefficients which minimize prediction error energy in the fractional-accuracy motion compensation from among the weighted filter coefficients; a step of interpolating fractional-accuracy pixels for a reference picture by application of an interpolation filter with the selected weighted filter coefficients and encoding an input picture with the fractional-accuracy motion compensation; and a step of encoding the weight parameters used for generating the selected weighted filter coefficients and the interpolation filter coefficients and adding encoded weight parameters and encoded interpolation filter coefficients to an encoded bitstream.

Method and apparatus for encoding video, method and apparatus for decoding video, and programs therefor

A reduction in residual energy of inter-frame prediction with motion compensation and improvement in encoding efficiency are achieved by using a region-dividing type adaptive interpolation filter that takes an edge property of a picture into consideration. An edge calculation unit calculates edge information from reference picture data designated by a motion vector. A region dividing unit divides an encoding target frame into a plurality of regions that are units to which interpolation filters are adaptively applied based on the edge information. A filter coefficient optimizing unit optimizes an interpolation filter for a fractional-accuracy pixel for each of the regions. A reference picture interpolating unit interpolates the fractional-accuracy pixel of a reference picture using the optimized interpolation filter, and a predictive encoding unit performs predictive encoding using motion compensation of fractional-accuracy.

The computational complexity of a denoising filter is reduced while suppressing a reduction in coding efficiency. In a video encoding/decoding apparatus which uses a loop filter, a deviation degree calculating unit calculates the degree of deviation between a denoising target pixel and a surrounding pixel using a decoded image. A template shape setting unit limits a template shape so that its size is proportional to the degree of deviation relative to the maximum value of the degree of deviation in the decoded image. When noise of the target pixel is removed, weighted in accordance with the degree of similarity between a template of the target pixel and a template of each of search points in a search shape and the weighted sum of pixel values at the search points, the loop filter performs template matching using the limited template shape and removes noise of the target pixel.

Video encoding/decoding methods, video encoding/decoding apparatuses, and programs therefor

In an image processing apparatus, an edge direction detection unit calculates an edge direction using a denoising target image. A search shape setting unit sets a search shape in which the number of search points along the direction perpendicular to the edge direction is smaller than the number of search points along the edge direction, using the calculated edge direction as an index used for limiting the search shape. When noise of a target pixel is removed with a weight in accordance with the degree of template similarity between a template for the target pixel and a template for each of search points within a search shape and the weighted sum of pixel values at the search points, a filter execution unit executes a process of performing template matching on only search points within the set search shape and removing the noise of the target pixel.

Image processing method, image processing apparatus, video encoding/decoding methods, video encoding/decoding apparatuses, and non-transitory computer-readable media therefor that perform denoising by means of template matching using search shape that is set in accordance with edge direction of image

A motion vector predictive encoding method, a motion vector decoding method, a predictive encoding apparatus, a decoding apparatuses, and storage media storing motion vector predictive encoding and decoding programs are provided, thereby reducing the amount of generated code with respect to the motion vector, and improving the efficiency of the motion-vector prediction. If the motion-compensating mode of the target small block to be encoded is the global motion compensation, the encoding mode of an already-encoded small block is the interframe coding mode, and the motion-compensating mode of the already-encoded small block is the global motion compensation, then the motion vector of the translational motion model is determined for each pixel of the already-encoded small block, based on the global motion vector (steps S-S). Next, the representative motion vector is calculated as the predicted vector, based on the motion vector of each pixel of the already-encoded small block (step S). Finally, the prediction error is calculated for each component of the motion vector and each prediction error is encoded (steps Sand S).

Motion vector predictive encoding and decoding method using prediction of motion vector of target block based on representative motion vector

A motion vector predictive encoding method, a motion vector decoding method, a predictive encoding apparatus, a decoding apparatuses, and storage media storing motion vector predictive encoding and decoding programs are provided, thereby reducing the amount of generated code with respect to the motion vector, and improving the efficiency of the motion-vector prediction. If the motion-compensating mode of the target small block to be encoded is the global motion compensation, the encoding mode of an already-encoded small block is the interframe coding mode, and the motion-compensating mode of the already-encoded small block is the global motion compensation, then the motion vector of the translational motion model is determined for each pixel of the already-encoded small block, based on the global motion vector (steps S&#x2013;S). Next, the representative motion vector is calculated as the predicted vector, based on the motion vector of each pixel of the already-encoded small block (step S). Finally, the prediction error is calculated for each component of the motion vector and each prediction error is encoded (steps Sand S).

Motion vector predictive encoding method, motion vector decoding method, predictive encoding apparatus and decoding apparatus, and storage media storing motion vector predictive encoding and decoding programs

A moving image brightness variation compensation method for encoding digital moving images for transmission and storage, and for image processing when editing moving images, the moving image brightness variation compensation method comprising a step of compensating for overall brightness variations by correcting a luminance value x of each pixel according to the formula D&#xb7;x+D, wherein Dis a parameter indicating a gain change and Dis a parameter indicating a contrast change, the parameters representing overall luminance changes between a reference image plane and an image plane being processed.

Brightness-variation compensation method and coding/decoding apparatus for moving pictures

Video data predictive encoding methods using the two kinds of prediction modes, the global and local motion compensation modes, are provided, by which unnecessary MCSEL is reduced as much as possible, and the data compression efficiency is improved. In the encoder, after a code word MCBPC indicating the macroblock type and presence/absence of the DCT coefficient of each of two blocks for sending color-difference signals, a code word MCSEL indicating which motion-compensating mode, global or local, was adopted for the prediction of the current macroblock is output if the macroblock was not intraframe-encoded.

Predictive encoding and decoding methods of video data

Motion vector encoding and decoding methods, motion vector encoding and decoding apparatuses, and storage media storing motion vector encoding and decoding programs are provided, thereby reducing the amount of generated code with respect to the motion vector. First, the motion vector of a target block to be encoded is detected (step S ), and a prediction error vector is calculated (step S ). After the length component of the motion vector is calculated (step S ), the length component is variable-length-encoded (step S ). The length component is checked (step S ), and if the length component is not 0, the direction component is calculated (step S ). The table for encoding the direction component is selected according to the length component, and the direction component is encoded (step S ).

Method for encoding and decoding moving vector, encoder and decoder for moving vector, and recording medium stored with encoding and decoding programs for moving vector

A moving image brightness variation compensation method for encoding digital moving images for transmission and storage, and for image processing when editing moving images, the moving image brightness variation compensation method comprising a step of compensating for overall brightness variations by correcting a luminance value x of each pixel according to the formula D &middot;x&plus;D , wherein D is a parameter indicating a gain change and D is a parameter indicating a contrast change, the parameters representing overall luminance changes between a reference image plane and an image plane being processed.

A moving image brightness variation compensation method for encoding digital moving images for transmission and storage, and for image processing when editing moving images, the moving image brightness variation compensation method comprising a step of compensating for overall brightness variations by correcting a luminance value x of each pixel according to the formula D,&middot;x&plus;D,, wherein D,is a parameter indicating a gain change and D,is a parameter indicating a contrast change, the parameters representing overall luminance changes between a reference image plane and an image plane being processed.

Our overlapped motion compensation unit and method, which is a motion compensation mechanism employing an overlapped block structure, minimize blocking effects prevalent in convention motion compensation. Our overlapped motion compensation unit and method are implemented on the basis of analysis/synthesis filter banks employed for coding resulting in compatibility between the block structure used for motion compensation and for coding. Our encoder, decoder, and coding method employ our novel overlapped motion compensation technique in combination with analysis/synthesis filter banks such as LOT to achieve improvements in coding efficiency and image quality above that of conventional image coders and coding methods. Specifically, in our encoder, decoder, and coding method, blocking effects prevalent in coders employing conventional motion compensation techniques and discrete cosine transforms are minimized and coding efficiency and image quality are maximized.

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Yokosuka, Japan

Hirohisa Jozawa