Patent ID: 6119140
Filing Date: 2000-09-12
Classification: G06F

Abstract:
An 8.times.8 two-dimensional inverse discrete cosine transform circuit that performs an 8-point one-dimensional inverse discrete cosine transform in a row direction and then performs an 8-point one-dimensional inverse discrete cosine transform in a column direction based on the result of said 8-point one-dimensional inverse discrete cosine transform in a row direction, so that the 8.times.8 two-dimensional inverse discrete cosine transform is realized, comprising:a first row arithmetic section for realizing a first 8-point one-dimensional inverse discrete cosine transform of a former part of a DCT (Discrete Cosine Transform) transformed domain signal Xij in four parallel mode to obtain a first arithmetic result, wherein i represents a horizontal address having an integer value of 0 to 7, j represents a vertical address having an integer value of 0 to 7, and said DCT transformed domain signals Xij are represented by executing horizontal direction transform and vertical direction transform and shifting by four bits leftward;a second row arithmetic section for realizing a second 8-point one-dimensional inverse discrete cosine transform of a latter part of the DCT transformed domain signal in four parallel mode to obtain a second arithmetic result;a replacement section for implementing a horizontal replacement of said first arithmetic result to output a first replacement result and implementing a vertical replacement of said second arithmetic result to output a second replacement result;a first column arithmetic section for realizing a third 8-point one-dimensional inverse discrete cosine transform of said first replacement result in four parallel mode and performing integer conversion to obtain a third arithmetic result; anda second column arithmetic section for realizing a fourth 8-point one-dimensional inverse discrete cosine transform of said second replacement result in four parallel mode and performing integer conversion to obtain a fourth arithmetic result;whereby said third arithmetic result and said fourth arithmetic result are output as arithmetic results of the 8.times.8 two-dimensional discrete inverse cosine transform.