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 computer-readable medium having stored thereon an image decoding program which, when executed by a computer, performs the steps of storing a reference image which is a previously decoded image, receiving information including motion vector information and rounding method information specifying a rounding method used in synthesizing a prediction image, and synthesizing a prediction image by performing motion compensation using the motion vector information and the reference image. The step of synthesizing a prediction image includes the step of performing either a positive rounding method or a negative rounding method for interpolating intensity values of pixels in performing the motion compensation according to the rounding method information, but enables performance of both the positive rounding method and the negative rounding method for interpolating intensity values of pixels in performing the motion compensation.

Abstract: A method of decoding images includes the steps of extracting motion vector information and quantized DCT coefficients from input information to be decoded, synthesizing a prediction image by performing motion compensation using the motion vector information and a reference image which is a previously decoded image, and synthesizing a decoded image by adding the prediction image to an error image obtained by applying dequantization and inverse DCT conversion to the quantized DCT coefficients. The motion compensation is performable using a positive rounding method and a negative rounding method for interpolating intensity values of pixels in performing the motion compensation.

Abstract: An image decoder includes a memory which stores a reference image which is a previously decoded image, and a synthesizer which receives motion vector information and rounding method information specifying a rounding method using in synthesizing a prediction image, and synthesizes a prediction image by performing motion compensation using the motion vector information and the reference image. The synthesizer performs either a positive rounding method or a negative rounding method for interpolating intensity values of pixels in performing the motion compensation according to the rounding method information, but enables performance of both the positive rounding method and the negative rounding method for interpolating intensity values of pixels in performing the motion compensation. The rounding method information specifies either the positive rounding method or the negative rounding method.

Abstract: An image decoder includes a demultiplexer which extracts motion vector information and quantized DCT coefficients from input information to be decoded, a dequantizer which dequantizes the quantized DCT coefficients to obtain DCT coefficients, an inverse DCT converter which performs inverse DCT conversion on the DCT coefficients to obtain an error image, a prediction image synthesizer which synthesizes a prediction image by performing motion compensation using the motion vector information and a reference image which is a previously decoded image, and an adder which adds the prediction image to the error image to obtain a decoded image. The motion compensation is performable using a positive rounding method and a negative rounding method for interpolating intensity values of pixels in performing the motion compensation.

Abstract: A computer-readable medium having stored thereon an image decoding program which, when executed by a computer, performs the steps of extracting motion vector information and quantized DCT coefficients from input information to be decoded, synthesizing a prediction image by performing motion compensation using the motion vector information and a reference image which is a previously decoded image, synthesizing a decoded image by adding the prediction image to an error image obtained by applying dequantization and inverse DCT conversion to the quantized DCT coefficients. The motion compensation is performable using a positive rounding method and a negative rounding method for interpolating intensity values of pixels in performing the motion compensation.

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 providing an output 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: In order to prevent accumulation of rounding errors caused by the integer-based bilinear interpolation used in the motion compensation process of image coding and decoding methods, two types of P frames are used for unidirectional motion compensation prediction: P+ frames, which round the results of bilinear interpolation with real number operations to the nearest integer and round half integer values (0.5 added to an integer) away from zero; and P− frames, which differ from P+ frames in that the above mentioned half integer values are rounded towards zero. Utilizing both of these P+ and P− frames enables canceling of rounding errors and prevents the accumulation of rounding errors.

Abstract: A method and apparatus for coding an image including calculation of motion vectors of vertices of a patch in an image being encoded and providing an output 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: Two arbitrary kinds of block images selected from the LMC block image, GMC block image and G-LMC block image, which are respectively synthesized by the local motion compensation, global motion compensation and global-local motion compensation, are averaged to produce an average block image, any one block image is selected from those LMC block image, GMC block image, G-LMC block image and average block image, and a prediction error signal is produced from the difference between this selected block image and the image within a block of the original image. Therefore, the coding characteristics can be improved.

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, decoding. The method and apparatus includes calculation of motion vectors of vertices of a patch in an image being encoded and outputting information of motion vectors of vertices and information that specifies the values of horizontal and vertical components of motion vector for each pixel in the patch which are an integer multiple of 1/d of the distance between adjacent pixels, wherein d is an integer not less than 2.

Abstract: The electric power consumption by a terminal used for communication of multimedia information is controlled by changing the quality of transmitted information. The terminal is provided with input means (101, 102, 106 and 107) through which such information as images and sounds is inputted, channel control sections (123 and 124) which output the input information to channels and receive information from the channels, output means (103, 104, 108, 109 and 105) which output the information received from the channels in the form of images, sounds, etc., a codec means (110) which is provided between the input and output means and the control sections, encodes the input information in one of multiple encoding modes in which electric power is differently consumed, and decodes the information inputted from the channels, and a control section (133) which controls the selection of the encoding mode.

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: In a video coding/decoding system, a high-resolution reference image having pixels in closer relation is produced by applying the interpolating operation of a luminance value to a reference image. In the matching process for motion estimation, when the luminance value of a point lacking a pixel in the reference image becomes required, the luminance value of a pixel at a point nearest to the high-resolution reference image is approximated without computing the interpolation. As a result, the number of times the interpolation of the luminance value is computed can be reduced, thereby reducing the circuit scale or the processing time. Also, the horizontal and vertical components of the motion vector of each pixel used for synthesizing a predicted image are defined to assume only a value equal to an integer multiple of 1/d1 and 1/d2 (d1 and d2 being position integers) of the distance between adjacent pixels.

Abstract: The electric power consumption by a terminal used for communication of multimedia information is controlled by changing the quality of transmitted information. The terminal is provided with input (101, 102, 106 and 107) through which such information as images and sounds is inputted, channel control sections (123 and 124) which output the input information to channels and receive information from the channels, output (103, 104, 108, 109 and 105) which output the information received from the channels in the form of images, sounds, etc., a codec (110) which is provided between the input and output and the control sections, encodes the input information in one of multiple encoding modes in which electric power is differently consumed, and decodes the information inputted from the channels, and a control section (133) which controls the selection of the encoding mode.

Abstract: A novel optical molding process for forming a three-dimensional article from a photosensitive resin which is liquid at normal temperatures which involves forming a plurality of laminated cured resin layers by a repetition of the step of forming a cured resin layer by selectively irradiating the surface of a photosensitive resin, wherein the photosensitive resin has been coagulated by cooling and the coagulated resin is irradiated to cure it. The process can produce a three-dimensional article having an overhanging part without producing warping in the finished product and without requiring a support for the overhanging part while this part is being optically molded.

Abstract: Software is transmitted for decoding a bit stream of coded data prior to transmitting the bit stream of coded data in order to shorten the time taken to start reproduction of the received bit stream of coded data on the reproducing side. The transmitted decoder software is compiled while a bit stream of data coded by a coding method known to the reproducing side is received on the reproducing side and reproduced thereby. Upon completion of compilation of the decoder software reproduction of the bit stream of data coded by the known coding method is switched to the reproduction of the bit stream of data coded by a coding method corresponding to the decoder software.

Abstract: In a video coding/decoding system, a high-resolution reference image having pixels in closer relation is produced by applying the interpolating operation of a luminance value to a reference image. In the matching process for motion estimation, when the luminance value of a point lacking a pixel in the reference image becomes required, the luminance value of a pixel at a point nearest to the high-resolution reference image is approximated without computing the interpolation. As a result, the number of times the interpolation of the luminance value is computed can be reduced, thereby reducing the circuit scale or the processing time. Also, the horizontal and vertical components of the motion vector of each pixel used for synthesizing a predicted image are defined to assume only a value equal to an integer multiple of 1/d1 and 1/d2 (d1 and d2 being positive integers) of the distance between adjacent pixels.