Abstract: A computer-readable medium having stored thereon an image decoding program which, when executed by a computer, performs image decoding, wherein the 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; 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; 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: 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; wherein the rounding method information is included in a header section of the coded information of the currently decoded image; and wherein the rounding method information specifies one of a plurality of values.

Abstract: A computer-readable medium having stored thereon an image decoding program which, when executed by a computer, performs image decoding, wherein the 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; 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: A computer-readable medium having stored thereon an image decoding program which, when executed by a computer, performs image decoding, wherein 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; 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; 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: 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 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 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

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: 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; 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: 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; wherein the rounding method information is included in coded information of the currently decoded image; and wherein the rounding method information specifies one of a plurality of values.

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: 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 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 is performed using a rounding method specified by the rounding method information 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; and wherein the rounding method information specifies one of a plurality o

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; wherein the rounding method information is included in a header section of the coded information of the currently decoded image; and wherein the rounding method information specifies one of a plurality of values.

Abstract: A computer-readable medium having stored thereon an image decoding program which, when executed by a computer, performs image decoding, wherein the 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; 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, 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; 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 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 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

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; wherein the rounding method information is included in coded information of the currently decoded image; and wherein the rounding method information specifies one of a plurality of values.

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 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 is performed using a rounding method specified by the rounding method information 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; and wherein the rounding method information specifies one of a plurality o

Abstract: A computer-readable medium having stored thereon an image decoding program which, when executed by a computer, performs image decoding, wherein 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; 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; 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, 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; 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 to DCT coefficients; an inverse DCT converter converting to DCT coefficients to obtain an error image; a synthesizer synthesizing a prediction image of a currently decoded image by performing motion compensation using the motion vector information, the rounding method information, and a reference image which is a previously decoded image; and an adder adding the prediction image to the error image to obtain a decoded image; 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 positive and negative rounding methods and is performed using a rounding method specified by the rounding method information specifying one of a plura

Abstract: A computer-readable medium having stored thereon an image decoding program which, when executed by a computer, performs image decoding, wherein the 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; 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; and wherein one of the two values specifies a positive rounding method, and another one of the two values specifies a negative rounding method.