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 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: An image coding method is utilized to provide high quality images without error accumulation. Such an image coding method comprises estimating motion vectors between an input image to be coded and a reference image; synthesizing a prediction image of the input image using the motion vectors and the reference image; generating a difference image by calculating a difference between the input image and the prediction image; and outputting coded information of the input image including information related to the difference image and the motion vectors. The prediction image is synthesized by calculating intensity values at points where no pixels actually exist in the reference image by interpolation. Such an interpolation is 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 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 digital portable terminal is utilized to obtain high quality images without error accumulation using plus and/or minus rounding of images. Such a digital portable terminal comprises an antenna for sending digital signals; an input device for acquiring image information; a frame memory for recording a decoded image of a reference frame; a block matching section for estimating motion vectors and synthesizing a predicted image of a current frame by performing motion compensation between the decoded image of the reference frame and an input image of the current frame; a DCT converter for performing DCT conversion of a difference between the input image of the current frame and the predicted image of the current frame to obtain DCT coefficients; a quantizer for quantizing the DCT coefficients; and a multiplexer for multiplexing information related to quantized DCT coefficients, the motion vectors and a rounding method used for pixel value interpolation in said motion compensation.

Abstract: A recording medium is provided to store coded information of an image sequence to obtain high quality images without error accumulation. Such coded information includes coded data of P and B frames, wherein the coded data of a P frame includes information specifying a positive rounding method or a negative rounding method which is used for interpolating intensity values of pixels in motion compensation, when the P frame is decoded; and wherein the coded data of a B frame does not include information specifying a rounding method which is used for interpolating intensity values of pixels in motion compensation, when the B frame is decoded.

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: 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 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: A recording medium is provided to store coded information of an image sequence to obtain high quality images without error accumulation. Such coded information includes coded data of P and B frames, wherein the coded data of a P frame includes information specifying a positive rounding method or a negative rounding method which is used for interpolating intensity values of pixels in motion compensation, when the P frame is decoded; and wherein the coded data of a B frame does not include information specifying a rounding method which is used for interpolating intensity values of pixels in motion compensation, when the B frame is decoded.

Abstract: An image coding method is utilized to provide high quality images without error accumulation. Such an image coding method comprises estimating motion vectors between an input image to be coded and a reference image; synthesizing a prediction image of the input image using the motion vectors and the reference image; generating a difference image by calculating a difference between the input image and the prediction image; and outputting coded information of the input image including information related to the difference image and the motion vectors. The prediction image is synthesized by calculating intensity values at points where no pixels actually exist in the reference image by interpolation. Such an interpolation is 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 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 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 digital portable terminal is utilized to obtain high quality images without error accumulation using plus and/or minus rounding of images. Such a digital portable terminal comprises an antenna for sending digital signals; an input device for acquiring image information; a frame memory for recording a decoded image of a reference frame; a block matching section for estimating motion vectors and synthesizing a predicted image of a current frame by performing motion compensation between the decoded image of the reference frame and an input image of the current frame; a DCT converter for performing DCT conversion of a difference between the input image of the current frame and the predicted image of the current frame to obtain DCT coefficients; a quantizer for quantizing the DCT coefficients; and a multiplexer for multiplexing information related to quantized DCT coefficients, the motion vectors and a rounding method used for pixel value interpolation in said motion compensation.