Abstract: A computer-readable medium having stored thereon an image decoding program which, when executed by a computer, performs: storing a reference image which is a previously decoded image; receiving coded information including motion vector information and rounding method information specifying a rounding method used in synthesizing a prediction image; and synthesizing the prediction image by performing motion compensation using the motion vector information and the reference image; wherein the synthesizing a prediction image is performable using positive and negative rounding methods for interpolating intensity values of pixels; wherein the interpolation of intensity values of pixels uses a rounding method specified by the rounding method information; wherein the rounding method information is included in coded information of the currently decoded image; wherein the rounding method information specifies one of two values specifying a positive rounding method and a negative rounding method, respectively.

Abstract: An image decoder wherein motion compensation is performed with half-pixel accuracy and uses bilinear interpolation to calculate intensity values of chrominance or luminance at points where no pixels actually exist in the reference image, the bilinear interpolation being performable using a positive rounding method and a negative rounding method; wherein the bilinear interpolation is performed using a rounding method specified by the rounding method information; wherein the rounding method information is included in coded information of the currently decoded image; wherein the rounding method information specifies one of two values; and wherein one of the two values specifies a positive rounding method, and another one of the two values specifies a negative rounding method.

Abstract: A computer-readable medium having stored thereon an image decoding program which, when executed by a computer, performs: storing a reference image which is a previously decoded image; receiving coded information including motion vector information and rounding method information specifying a rounding method used in synthesizing a prediction image of a currently decoded image; and synthesizing the prediction image by performing motion compensation using the motion vector information and the reference image; wherein the step of synthesizing a prediction image is performable using a positive rounding method and a negative rounding method for interpolating intensity values of pixels; wherein the interpolation of intensity values of pixels is performed using a rounding method specified by the rounding method information; and wherein the rounding method information is included in coded information of the currently decoded image.

Abstract: An image decoder, wherein the motion compensation is performed with half-pixel accuracy and uses bilinear interpolation to calculate intensity values of chrominance or luminance at points where no pixels actually exist in the reference image, the bilinear interpolation being performable using a positive rounding method and a negative rounding method; wherein the bilinear interpolation is performed using a rounding method specified by the rounding method information; wherein the rounding method information is included in coded information of the currently decoded image; and wherein the rounding method information is included in a header section of the coded information of the currently decoded image.

Abstract: An image decoder, wherein motion compensation is performed with half-pixel accuracy and uses bilinear interpolation to calculate intensity values of chrominance or luminance at points where no pixels actually exist in the reference image, the bilinear interpolation being performable using a positive rounding method and a negative rounding method; wherein the bilinear interpolation is performed using a rounding method specified by the rounding method information; wherein the rounding method information is included in coded information of the currently decoded image; wherein the rounding method information is included in a header section of the coded information of the currently decoded image; wherein the rounding method information specifies one of two values; wherein one of the two values specifies a positive rounding method, and another one of the two values specifies a negative rounding method; and wherein the rounding method information consists of one bit.

Abstract: An image decoder including: a demultiplexer extracting motion vector information, quantized DCT coefficients, and rounding method information; a dequantizer dequantizing the quantized DCT coefficients to obtain DCT coefficients; an inverse DCT converter performing inverse DCT conversion on the DCT coefficients to obtain an error image; a prediction image synthesizer synthesizing a prediction image by performing motion compensation using the motion vector information, the rounding method information, and a reference previously decoded image; and an adder adding the prediction image to the error image to obtain a decoded image. Motion compensation is performed with half-pixel accuracy and bilinear interpolation to calculate intensity values of chrominance or luminance at points where no pixels actually exist in the reference image, using positive and negative rounding methods.

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 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 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 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: The invention relates to a multimedia communication terminal that enables error resilience control according to a situation of a communication channel and the preference of a user based upon a multimedia communication terminal using a communication channel where a transmission error occurs, means for directly receiving a request of a user in relation to error resilience is provided to a receiving terminal, the information is transmitted to a transmitting terminal and the level of error resilience of a coded bit stream is changed.

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 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 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 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 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 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 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 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 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.