Abstract: 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.

Abstract: A video encoding method includes setting candidates for reference pixels to pixels within a predetermined distance range measured from an encoding target block; generating a predicted signal by sequentially selecting reference pixels used for the intra prediction of the encoding target block from among the reference pixel candidates while changing a distance condition from the encoding target block, and by generating the predicted signal based on the reference pixels for each distance condition; computing an encoding cost required for subjecting the encoding target block to intra prediction encoding using each generated predicted signal; finally determining reference pixels used for the intra prediction of the encoding target block based on each computed encoding cost; and encoding information which indicates the position of the determined reference pixels.

Abstract: A video encoding apparatus reduces residual energy of motion-compensated inter-frame prediction and improves the coding efficiency in encoding of an image in which optimal values of interpolation filter coefficients are changed in time and space. In the video encoding apparatus, a region division unit sequentially selects region division schemes one by one from among a plurality of prepared region division schemes, and divides a region of an image to be encoded. An interpolation filter coefficient switching unit switches interpolation filter coefficients of a decimal precision pixel for each divided region, and a predictive encoding unit performs predictive encoding. A region division mode decoding section selects a region division scheme, in which a cost is minimized among rate distortion costs calculated for each region division scheme. Using the selected region division scheme, the predictive encoding unit and a variable length encoding unit encode the image to be encoded.

Abstract: 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.

Abstract: An information source encoding method for encoding a Gaussian integer signal includes the steps of: inputting a signal value sequence of a Gaussian integer signal as an encoding target; transforming signal values included in the input signal value sequence into integer pairs, each having two integers, arranged in the input order; regarding each of the integer pairs as a lattice point on two-dimensional coordinates, and obtaining integer values greater than or equal to zero by performing a two-dimensional-to-one-dimensional mapping in which the shorter the distance from each lattice point to the origin, the smaller the value assigned to the lattice point by the mapping; and encoding the integer values using codes which are used for encoding an information source that follows an exponential distribution.

Abstract: An automatic producing method for a predicted value generation procedure that predicts a value of an encoding target pixel by using a previously-decoded pixel. A parent population is generated by randomly producing predicted value generation procedures each of which is indicated by a tree structure, and a plurality of predicted value generation procedures are selected as parents from the parent population. One or more predicted value generation procedures are generated as children based on a predetermined tree structure developing method which subjects the selected predicted value generation procedures to a development where an existing predicted value generation function can be an end node of a tree.

Abstract: In scalable video encoding, incidence rates of combinations of optimum prediction modes to be selected for spatially corresponding blocks of an upper layer and a lower layer are determined based on an optimum prediction mode that was selected in a conventional encoding, and then a correspondence table that describes relationships therebetween is created. Subsequently, the combinations of the selected optimum prediction modes described in the correspondence table are narrowed down based on the value of the incidence rate so as to create prediction mode correspondence information that describes the combinations of the optimum prediction mode narrowed down.

Abstract: A direction is detected for each block in which a pixel value is changed which is represented by an edge that indicates a direction of change in pixel value in each block, a direction in which a deblocking filter is to be applied to a block boundary is determined based on a direction of an edge detected for a block to be processed which includes the block boundary subject to deblocking and on a direction of an edge detected for a block contacting the block to be processed, and the deblocking filter is applied to the block boundary in accordance with the determined direction.

Abstract: Highly efficient lossless decoding is realized under the condition that codes transmitted as a base part are compatible with the H.264 standard. An orthogonal transformation section (12) performs orthogonal transformation of residual signals (Rorig), acquires transform coefficients (Xorig), and a quantization section (13) quantizes the transform coefficients. An existential space determination section (14) obtains information on upper limits and lower limits of the respective coefficients (an existential space of transform coefficients) from quantization information.

Abstract: A scalable video encoding method of performing encoding by predicting an upper-layer signal having a relatively high spatial resolution by means of interpolation using an immediately-lower-layer signal having a relatively low spatial resolution. The method computes a first weighting coefficient for each image area of a predetermined unit size in a search for estimating a motion between an encoding target image area in an upper layer and a reference image area, where the first weighting coefficient is computed based on a brightness variation between an image area, which belongs to an immediately-lower layer and has the same spatial position as the encoding target image area, and the reference image area; and performs a motion estimation using a signal which is obtained by correcting a decoded signal of the reference image area by the first weighting coefficient and functions as an estimated signal in the motion estimation, so as to compute a motion vector.

Abstract: An image encoding method for encoding a pixel value of an encoding target by using a predicted value generated by means of spatial or temporal prediction using a previously-decoded image. The method performs prediction of the pixel value of the encoding target and obtains the predicted value; computes data of a probability distribution which indicates what value an original pixel value has for the obtained predicted value, by shifting, in accordance with the predicted value, difference distribution data of a difference between the original pixel value and the predicted value in predictive encoding, where the difference distribution data is stored in advance; clips the obtained data of the probability distribution so as to contain the data in a range from a lower limit to an upper limit for possible values of the original pixel value; and encodes the pixel value of the encoding target by using the clipped data of the probability distribution of the original pixel value from the lower limit to the upper limit.

Abstract: A video scalable encoding method calculates a weight coefficient which includes a proportional coefficient and an offset coefficient and indicates brightness variation between an encoding target image region and a reference image region in an upper layer, calculates a motion vector by applying the weight coefficient to an image signal of a reference image region as a search target and executing motion estimation, and generates a prediction signal by applying the weight coefficient to a decoded signal of a reference image region indicated by the motion vector and executing motion compensation. Based on encoding information of an immediately-lower image region in an immediately-lower layer, which is present at spatially the same position as the encoding target image region, a data structure of the weight coefficient is determined.

Abstract: A method for encoding an image using an intraframe prediction is provided which includes selecting a gradient of a pixel value that is indicated by an image signal to be predicted among a plurality of gradient candidates, generating a predicted signal by applying a gradient in accordance with the distance from a prediction reference pixel based on the gradient, intraframe-encoding the image signal to be predicted based on the predicted signal, and encoding information indicating the size of the selected gradient. Alternatively, the method includes estimating the gradient of a pixel value that is indicated by an image signal to be predicted based on an image signal which has already been encoded, generating a predicted signal by applying a gradient in accordance with the distance from a prediction reference pixel based on the gradient, and intraframe-encoding the image signal to be predicted based on the predicted signal.

Abstract: A scalable encoding method for decomposing an image signal into signals assigned to layers so as to encode the image signal includes encoding an image signal of at least one target layer among the layers based on an amount of codes allocated to the target layer; outputting a residual signal of the target layer corresponding to a difference between the pre-encoded image signal and an image signal decoded from the encoded image signal; determining a target amount of codes allocated for encoding the residual signal based on the residual signal, an amount of codes allocated to an objective layer, and an image signal of the objective layer; encoding the residual signal based on the determined target amount of codes; revising the amount of codes allocated to the objective layer based on the target amount of codes; and encoding the image signal of the objective layer based on the revised amount.

Abstract: An information source encoding method for encoding a Gaussian integer signal includes the steps of: inputting a signal value sequence of a Gaussian integer signal as an encoding target; transforming signal values included in the input signal value sequence into integer pairs, each having two integers, arranged in the input order; regarding each of the integer pairs as a lattice point on two-dimensional coordinates, and obtaining integer values greater than or equal to zero by performing a two-dimensional-to-one-dimensional mapping in which the shorter the distance from each lattice point to the origin, the smaller the value assigned to the lattice point by the mapping; and encoding the integer values using codes which are used for encoding an information source that follows an exponential distribution.

Abstract: A video encoding method includes setting candidates for reference pixels to pixels within a predetermined distance range measured from an encoding target block; generating a predicted signal by sequentially selecting reference pixels used for the intra prediction of the encoding target block from among the reference pixel candidates while changing a distance condition from the encoding target block, and by generating the predicted signal based on the reference pixels for each distance condition; computing an encoding cost required for subjecting the encoding target block to intra prediction encoding using each generated predicted signal; finally determining reference pixels used for the intra prediction of the encoding target block based on each computed encoding cost; and encoding information which indicates the position of the determined reference pixels.

Abstract: Highly efficient lossless decoding is realized under the condition that codes transmitted as a base part are compatible with the H.264 standard. An orthogonal transformation section (12) performs orthogonal transformation of residual signals (Rorig), acquires transform coefficients (Xorig), and a quantization section (13) quantizes the transform coefficients. An existential space determination section (14) obtains information on upper limits and lower limits of the respective coefficients (an existential space of transform coefficients) from quantization information.

Abstract: A scalable encoding method for decomposing an image signal into signals assigned to layers so as to encode the image signal includes encoding an image signal of at least one target layer among the layers based on an amount of codes allocated to the target layer; outputting a residual signal of the target layer corresponding to a difference between the pre-encoded image signal and an image signal decoded from the encoded image signal; determining a target amount of codes allocated for encoding the residual signal based on the residual signal, an amount of codes allocated to an objective layer, and an image signal of the objective layer; encoding the residual signal based on the determined target amount of codes; revising the amount of codes allocated to the objective layer based on the target amount of codes; and encoding the image signal of the objective layer based on the revised amount.

Abstract: 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 S1-S5). 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 S6).

Abstract: 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 S1–S5). 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 S6).