| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a data converter calculating from a coefficient block of a two-dimensionally arrangement reversibly transformed DC coefficient data of the coefficient block with a simple constitution. <P>SOLUTION: A data converter calculating DC conversion coefficient which one of reversibly transformable integer conversion coefficients for a block from the block that consists of integer data of 4×4 two-dimensional arrangement, comprises: a parity arithmetic unit 400 partitioning the block into subblocks which consists of 4 data set beforehand, and for each subblock calculating a parity which has at least one value of 0 and 1 to indicate whether a sum total of 4 coefficient data composing each subblock is an even number or an odd number; a sum value calculation unit 510 calculating a sum value of all data in the block; an addition unit 520 adding the sum value calculated in the sum value calculation unit and the parity of each subblock calculated in the parity arithmetic unit; and a DC coefficient calculation unit 530 calculating the reversibly transformed DC coefficient of the block based on the value of addition result by the addition unit. <P>COPYRIGHT: (C)2012,JPO&INPIT |
