Abstract: An image decoding method including the steps of: receiving an encode bitstream including information of I and P frames; and executing motion compensation by synthesizing a predicted image of a current frame using motion vector information included in the encoded bitstream and a reference image which is a previously decoded image, wherein said motion compensation includes calculating intensity values at points where no pixels actually exist in the reference image by interpolation, wherein said interpolation is done according to information specifying a positive rounding method or a negative rounding method included in a header section of the encoded bitstream, when the current frame is a P frame, and wherein information specifying a positive rounding method or a negative rounding method is not included in a header section of the encoded bitstream when the current frame is an I frame.

Abstract: A recording medium having recorded thereon information related to coded data of an image sequence; wherein the information related to coded data of an image sequence is a set of coded frame information of a plurality of frames of an image sequence; wherein the coded frame information includes: information related to a difference image between an image of a current frame and a prediction image of the current frame, the prediction image being synthesized by performing motion compensation, information related to motion vectors estimated in performing the motion compensation, and rounding method information specifying either a positive rounding method or a negative rounding method for interpolating intensity values of pixels in performing the motion compensation when the input image is coded as a P frame, wherein no rounding method information is included in the coded frame information when the input image is coded as a B frame.

Abstract: An image coder including: a memory to store a reference image which is a previously decoded image; a block matching section to estimate motion vectors between an input image to be coded and the reference image, to synthesize a prediction image of the input image using the motion vectors and the reference image, and to generate a difference image by calculating a difference between the input image and the prediction image; and a multiplexer to produce coded information of the input image including information related to the difference image and the motion vectors, wherein the prediction image is synthesized by calculating intensity values at points where no pixels actually exist in the reference image by interpolation, wherein the interpolation is done using a positive rounding method or a negative rounding method when the input image is coded as a P frame, wherein the coded information of the input image coded as P frames includes information specifying the rounding method used in the interpolation, and where

Abstract: A recording medium having recorded thereon information related to coded data of an image sequence; wherein the information related to coded data of an image sequence is a set of coded frame information of a plurality of frames of an image sequence; wherein the coded frame information includes: information related to a difference image between an image of a current frame and a prediction image of the current frame, the prediction image being synthesized by performing motion compensation, information related to motion vectors estimated in performing the motion compensation, and rounding method information specifying either a positive rounding method or a negative rounding method for interpolating intensity values of pixels in performing the motion compensation when the input image is coded as a P frame, wherein no rounding method information is included in the coded frame information when the input image is coded as an I frame.

Abstract: A method of simplifying the arithmetic operation in a global motion compensation process approximates the motion vector field of the whole image without using many parameters. Motion vectors in the global motion compensation are found by the interpolation and/or extrapolation of the motion vectors of a plurality of representative points 602, 603 and 604 having particular features in the spatial distance thereof. Since the shift operation can be substituted for the division for synthesizing a predicted image of global motion compensation, the processing using a computer or a dedicated hardware is simplified.

Abstract: A recording medium having recorded thereon information of images coded by performing motion compensation is provided to obtain high quality images without error accumulation. Such information includes rounding method information specifying a positive rounding method or a negative rounding method for interpolation intensity values of pixels in performing the motion compensation.

Abstract: An image decoding method is utilized to obtain high quality images without error accumulation. Such an image decoding method comprises receiving an encoded bitstream including information of P and B frames, and executing motion compensation by synthesizing a predicted image of a current frame using motion vector information included in the encoded bitstream and a reference image which is a previously decoded image. The motion compensation includes calculating intensity values at points where no pixels actually exist in the reference image by interpolation performed according to information specifying a positive rounding method or a negative rounding method when the current frame is a P frame, and using a predetermined rounding method which is a positive rounding method or a negative rounding method when the current frame is a B frame.

Abstract: An image decoding method is utilized to obtain high quality images without error accumulation. Such an image decoding method comprises receiving an encoded bitstream including information of P and B frames, and executing motion compensation by synthesizing a predicted image of a current frame using motion vector information included in the encoded bitstream and a reference image which is a previously decoded image. The motion compensation includes calculating intensity values at points where no pixels actually exist in the reference image by interpolation performed according to information specifying a positive rounding method or a negative rounding method when the current frame is a P frame, and using a predetermined rounding method which is a positive rounding method or a negative rounding method when the current frame is a B frame.

Abstract: An image decoding method is utilized to obtain high quality images without error accumulation. Such an image decoding method comprises receiving an encoded bitstream including information of P and B frames, and executing motion compensation by synthesizing a predicted image of a current frame using motion vector information included in the encoded bitstream and a reference image which is a previously decoded image. The motion compensation includes calculating intensity values at points where no pixels actually exist in the reference image by interpolation performed according to information specifying a positive rounding method or a negative rounding method when the current frame is a P frame, and using a predetermined rounding method which is a positive rounding method or a negative rounding method when the current frame is a B frame.

Abstract: An image decoding method is utilized to obtain high quality images without error accumulation. Such an image decoding method comprises receiving an encoded bitstream including information of P and B frames, and executing motion compensation by synthesizing a predicted image of a current frame using motion vector information included in the encoded bitstream and a reference image which is a previously decoded image. The motion compensation includes calculating intensity values at points where no pixels actually exist in the reference image by interpolation performed according to information specifying a positive rounding method or a negative rounding method when the current frame is a P frame, and using a predetermined rounding method which is a positive rounding method or a negative rounding method when the current frame is a B frame.

Abstract: An image decoding method is utilized to obtain high quality images without error accumulation. Such an image decoding method comprises receiving an encoded bitstream including information of P and B frames, and executing motion compensation by synthesizing a predicted image of a current frame using motion vector information included in the encoded bitstream and a reference image which is a previously decoded image. The motion compensation includes calculating intensity values at points where no pixels actually exist in the reference image by interpolation performed according to information specifying a positive rounding method or a negative rounding method when the current frame is a P frame, and using a predetermined rounding method which is a positive rounding method or a negative rounding method when the current frame is a B frame.

Abstract: A method and apparatus for coding an image includes calculation of motion vectors of vertices of a patch in an image being encoded and transmitting information of horizontal and vertical components of the motion vectors of the vertices and information specifying that values of the horizontal and vertical components of a motion vector for each pixel in the patch are integral multiples of 1/d of a distance between adjacent pixels, where d is an integer not less than 2.

Abstract: A method and apparatus for simplifying an operation for the processing of a warping prediction of dividing an image into patches and deforming each patch by affine transform or bilinear transform. Motion vectors of a plurality of representative points in which a spatial interval has a special feature are obtained from at least one patch formed with a plurality of grid points. Information of the motion vectors are used for synthesis of a predicted image. The division for synthesizing a predicted image in the case of warping prediction is replaced with a shift operation, thereby simplifying the processing by a computer or exclusive hardware.

Abstract: A method and apparatus for coding an image includes calculation of motion vectors of vertices of a patch in an image being encoded and transmitting information of horizontal and vertical components of the motion vectors of the vertices and information specifying that values of the horizontal and vertical components of a motion vector for each pixel in the patch are integral multiples of 1/d of a distance between adjacent pixels, where d is an integer not less than 2.

Abstract: A method and apparatus for simplifying an operation for the processing of a warping prediction of dividing an image into patches and deforming each patch by affine transform or bilinear transform. Motion vectors of a plurality of representative points in which a spatial interval has a special feature are obtained from at least one patch formed with a plurality of grid points. Information of the motion vectors are used for synthesis of a predicted image. The division for synthesizing a predicted image in the case of warping prediction is replaced with a shift operation, thereby simplifying the processing by a computer or exclusive hardware.

Abstract: An image decoding method is utilized to obtain high quality images without error accumulation. Such an image decoding method comprises receiving an encoded bitstream including information of P and B frames, and executing motion compensation by synthesizing a predicted image of a current frame using motion vector information included in the encoded bitstream and a reference image which is a previously decoded image. The motion compensation includes calculating intensity values at points where no pixels actually exist in the reference image by interpolation performed according to information specifying a positive rounding method or a negative rounding method when the current frame is a P frame, and using a predetermined rounding method which is a positive rounding method or a negative rounding method when the current frame is a B frame.

Abstract: A method is provided to simplify the computation involved in global motion compensation and warping prediction in coding and decoding of motion compensated image signals. In the synthesis of a global motion compensated predicted image 1203 which predicts a current frame image from an immediately preceding frame image 1202 using motion vectors 1205 of plural representative points having a particular spatial interval in an image frame, a first interpolation/extrapolation 1207 is performed to calculate motion vectors of provisional representative points from motion vectors 1206 of representative points, and a second interpolation/extrapolation 1209 is then performed to calculate motion vectors 1210 for each pixel from motion vectors 1208 of the provisional representative points. A division performed when the predicted image is synthesized can be replaced by a shift computation involving a smaller number of bits, so the processing carried out by a computer or special hardware can be simplified.

Abstract: A method of simplifying the arithmetic operation in a global motion compensation process approximates the motion vector field of the whole image without using many parameters. Motion vectors in the global motion compensation are found by the interpolation and/or extrapolation of the motion vectors of a plurality of representative points 602, 603 and 604 having particular features in the spatial distance thereof. Since the shift operation can be substituted for the division for synthesizing a predicted image of global motion compensation, the processing using a computer or a dedicated hardware is simplified.

Abstract: A method and apparatus for simplifying an operation for the processing of a warping prediction of dividing an image into patches and deforming each patch by affine transform or bilinear transform. Motion vectors of a plurality of representative points in which a spatial interval has a special feature are obtained from at least one patch formed with a plurality of grid points. Information of the motion vectors are used for synthesis of a predicted image. The division for synthesizing a predicted image in the case of warping prediction is replaced with a shift operation, thereby simplifying the processing by a computer or exclusive hardware.

Abstract: A method and apparatus for coding an image includes calculation of motion vectors of vertices of a patch in an image being encoded and transmitting information of horizontal and vertical components of the motion vectors of the vertices and information specifying that values of the horizontal and vertical components of a motion vector for each pixel in the patch are integral multiples of 1/d of a distance between adjacent pixels, where d is an integer not less than 2.