Abstract: A variable length coding method is comprised of: a coefficient value scanning step in which an RL sequence generation unit, a reordering unit, and a binarization unit scan coefficient values within a block in a predetermined scanning order starting at a higher-frequency component toward a lower-frequency component; and an arithmetic coding step in which an arithmetic coding unit and a table storage unit perform arithmetic coding on the absolute values of the coefficient values according to the scanning order used in the coefficient value scanning step, by switching between probability tables for use, wherein, in the arithmetic coding step, a probability table to be used is switched to another probability table in one direction, when the arithmetic-coded absolute values of the coefficient values include an absolute value exceeding a predetermined threshold value.

Abstract: A picture coding apparatus includes a motion vector estimation unit and a motion compensation unit. The motion vector estimation unit selects one method for deriving a motion vector of a block to be motion-compensated, depending on a motion vector of a block located in a corner of a decoded macroblock from among a group of blocks that compose the decoded macroblock corresponding to the current macroblock to be coded and determines the motion vector derived by the selected method for derivation to be a candidate of the motion vector of the current macroblock to be coded. The motion compensation unit generates a predictive image of the block to be motion-compensated based on the estimated motion vector.

Abstract: A video encoder (70) for coding moving pictures comprising a buffer (16c) with a plurality of memory areas capable of storing frames composed of top fields and bottom fields, a motion estimation unit (19) operable to code, field by field, inputted pictures performing moving estimation and moving compensation by referring, field by field, to the picture data stored in a memory area, a motion compensation unit (16d), a subtractor (11), a transformation unit (13) and a quantization unit (14), a memory management unit (71) operable to manage, frame by frame, a plurality of memory areas, an inverse quantization unit (16a) and inverse discrete cosine transform unit (16b) operable to decode picture data in coded fields and store the picture data in the decoded field in any of the plurality of memory areas under the management by the memory management unit (71).

Abstract: A picture coding apparatus includes a motion vector estimation unit and a motion compensation unit. The motion vector estimation unit selects one method for deriving a motion vector of a block to be motion-compensated, depending on a motion vector of a block located in a corner of a decoded macroblock from among a group of blocks that compose the decoded macroblock corresponding to the current macroblock to be coded and determines the motion vector derived by the selected method for derivation to be a candidate of the motion vector of the current macroblock to be coded. The motion compensation unit generates a predictive image of the block to be motion-compensated based on the estimated motion vector.

Abstract: A video encoder (70) for coding moving pictures comprising a buffer (16c) with a plurality of memory areas capable of storing frames composed of top fields and bottom fields, a motion estimation unit (19) operable to code, field by field, inputted pictures performing moving estimation and moving compensation by referring, field by field, to the picture data stored in a memory area, a motion compensation unit (16d), a subtractor (11), a transformation unit (13) and a quantization unit (14), a memory management unit (71) operable to manage, frame by frame, a plurality of memory areas, an inverse quantization unit (16a) and inverse discrete cosine transform unit (16b) operable to decode picture data in coded fields and store the picture data in the decoded field in any of the plurality of memory areas under the management by the memory management unit (71).

Abstract: A moving picture coding apparatus includes a motion estimation unit (101) for performing motion estimation by fixing the one of two reference pictures as a reference picture indicated by an inputted default reference picture number DefRefNo and a variable length coding unit (107) for performing variable length coding on coded residual data ERes, a prediction type PredType, a reference picture number RefNo2 and motion vectors MV1, MV2 on a block-by-block basis, and outputting them as coded moving picture data Str.

Abstract: A moving picture coding apparatus includes a motion estimation unit (101) for performing motion estimation by fixing the one of two reference pictures as a reference picture indicated by an inputted default reference picture number DefRefNo and a variable length coding unit (107) for performing variable length coding on coded residual data ERes, a prediction type PredType, a reference picture number RefNo2 and motion vectors MV1, MV2 on a block-by-block basis, and outputting them as coded moving picture data Str.

Abstract: According to a picture coding method, a coded picture is stored, as a reference picture, into a storage unit; commands indicating correspondence between reference pictures and reference indices for designating reference pictures and coefficients used for generation of predictive images are generated; a reference picture being used when motion compensation is performed on a current block in a current picture to be coded is designated by a reference index; a predictive image is generated by performing linear prediction on a block being obtained by motion estimation within the designated reference picture, by use of a coefficient corresponding to the reference index; a coded image signal including a coded signal obtained by coding a prediction error being a difference between the current block in the current picture to be coded and the predictive image, the commands, the reference index and the coefficient is outputted.

Abstract: An image decoding method is provided which includes a time information determination step of determining time information of a current picture, a first reference picture referred to by the current picture and a second reference picture referred to by the current picture; a scaling parameter calculation step of calculating a scaling parameter based on a time distance between the first reference picture and a second reference picture; a weighting coefficient determination step of determining two weighting coefficients based on the scaling parameter; a predictive pixel value generation step of generating a predictive pixel value of the current picture by scaling a pixel value of the first reference picture and a pixel value of the second reference picture using the two weighting coefficients determined in the weighting coefficient determination step; and a decoding step of decoding the current picture using the predictive pixel value.

Abstract: A color signal processing device for generating image data to be displayed on a display device which represents a color by using at least four primary colors, includes an obtainer that obtains a color signal regarding three primary colors for image data composed of a plurality of pixels, a changer that changes a value of the obtained color signal regarding the three primary colors, and a converter that converts the changed color signal regarding the three primary colors into a color signal regarding four primary colors. When a predetermined region contains a color saturated pixel, the changer makes the value of the color signal of at least one color of the three primary colors smaller, for pixels contained in the predetermined region.

Abstract: A moving picture coding apparatus includes a motion compensation coding unit for deciding a coding mode for coding a current block to be coded and for generating predictive image data based on the coding mode, and includes a direct mode enable/disable judgment unit for judging whether or not scaling processing can be performed when the coding mode decided by the motion compensation coding unit is a temporal direct mode. When it is judged that the scaling processing cannot be performed, the motion compensation coding unit performs motion compensation either by using another coding mode or without the scaling processing.

Abstract: A video encoder (70) for coding moving pictures comprising a buffer (16c) with a plurality of memory areas capable of storing frames composed of top fields and bottom fields, a motion estimation unit (19) operable to code, field by field, inputted pictures performing moving estimation and moving compensation by referring, field by field, to the picture data stored in a memory area, a motion compensation unit (16d), a subtractor (11), a transformation unit (13) and a quantization unit (14), a memory management unit (71) operable to manage, frame by frame, a plurality of memory areas, an inverse quantization unit (16a) and inverse discrete cosine transform unit (16b) operable to decode picture data in coded fields and store the picture data in the decoded field in any of the plurality of memory areas under the management by the memory management unit (71).

Abstract: A video encoder (70) for coding moving pictures comprising a buffer (16c) with a plurality of memory areas capable of storing frames composed of top fields and bottom fields, a motion estimation unit (19) operable to code, field by field, inputted pictures performing moving estimation and moving compensation by referring, field by field, to the picture data stored in a memory area, a motion compensation unit (16d), a subtractor (11), a transformation unit (13) and a quantization unit (14), a memory management unit (71) operable to manage, frame by frame, a plurality of memory areas, an inverse quantization unit (16a) and inverse discrete cosine transform unit (16b) operable to decode picture data in coded fields and store the picture data in the decoded field in any of the plurality of memory areas under the management by the memory management unit (71).

Abstract: A video encoder (70) for coding moving pictures comprising a buffer (16c) with a plurality of memory areas capable of storing frames composed of top fields and bottom fields, a motion estimation unit (19) operable to code, field by field, inputted pictures performing moving estimation and moving compensation by referring, field by field, to the picture data stored in a memory area, a motion compensation unit (16d), a subtractor (11), a transformation unit (13) and a quantization unit (14), a memory management unit (71) operable to manage, frame by frame, a plurality of memory areas, an inverse quantization unit (16a) and inverse discrete cosine transform unit (16b) operable to decode picture data in coded fields and store the picture data in the decoded field in any of the plurality of memory areas under the management by the memory management unit (71).

Abstract: A moving picture coding apparatus includes an inter-pixel filter having filters for filtering decoded image data so as to remove block distortion which is high frequency noise around block boundaries. The inter-pixel filter includes filters having different filtering strengths. The coding apparatus also includes a filter processing control unit for determining a filtering strength of the inter-pixel filter.

Abstract: A moving picture coding apparatus includes an inter-pixel filter having filters for filtering decoded image data so as to remove block distortion which is high frequency noise around block boundaries. The inter-pixel filter includes filters having different filtering strengths. The coding apparatus also includes a filter processing control unit for determining a filtering strength of the inter-pixel filter.

Abstract: A picture coding apparatus includes a motion vector estimation unit and a motion compensation unit. The motion vector estimation unit selects one method for deriving a motion vector of a block to be motion-compensated, depending on a motion vector of a block located in a corner of a decoded macroblock from among a group of blocks that compose the decoded macroblock corresponding to the current macroblock to be coded and determines the motion vector derived by the selected method for derivation to be a candidate of the motion vector of the current macroblock to be coded. The motion compensation unit generates a predictive image of the block to be motion-compensated based on the estimated motion vector.

Abstract: An image decoding method is provided which includes a time information determination step of determining time information of a current picture, a first reference picture referred to by the current picture and a second reference picture referred to by the current picture; a scaling parameter calculation step of calculating a scaling parameter based on a time distance between the first reference picture and a second reference picture; a weighting coefficient determination step of determining two weighting coefficients based on the scaling parameter; a predictive pixel value generation step of generating a predictive pixel value of the current picture by scaling a pixel value of the first reference picture and a pixel value of the second reference picture using the two weighting coefficients determined in the weighting coefficient determination step; and a decoding step of decoding the current picture using the predictive pixel value.

Abstract: A communication terminal eliminates collision of access request signals simultaneously transmitted from communication terminals in a local cell, prevents generation of interference signals in another cell adjacent to the local cell, and improves local cell throughput. A base station controls transmission power of the access permission signal so as to prevent generation of an interference signal in another cell adjacent to the local cell. A use sub-channel selection unit has a correspondence table between the reception quality of the pilot signals divided into classes and the sub-channel allocated to the classes. According to the table, the use sub-channel selection unit selects a sub-channel group of RACH correlated to the measurement result of the reception quality of the pilot signals reported from the reception quality measurement unit. One sub-channel to be used for transmission of the access request signal is selected at random from the sub-channel group selected.

Abstract: A moving picture coding apparatus includes an inter-pixel filter having filters for filtering decoded image data so as to remove block distortion which is high frequency noise around block boundaries. The inter-pixel filter includes filters having different filtering strengths. The coding apparatus also includes a filter processing control unit for determining a filtering strength of the inter-pixel filter.