Patent ID: 6134571
Filing Date: 2000-10-17
Classification: G06F,H03H

Abstract:
An implicit DST-based filter for filtering an information signal composed of blocks of discrete cosine transform (DCT) coefficients to generate a filtered information signal composed of blocks of DCT coefficients, the filter having characteristics defined by a linear convolution kernel and comprising:deriving means for deriving intermediate blocks of DCT coefficients from neighboring ones of the blocks of DCT coefficients constituting the information signal;matrix multiplying modules in which the intermediate blocks of DCT coefficients are multiplied by multiplying matrices obtained by absorbing a cosine-to-sine transform and a sine-to-cosine transform into kernel matrices derived from the linear convolution kernel, the multiplying matrices including elements; anda summing module in which blocks of DCT coefficients generated by the matrix multiplication modules are summed to generate the blocks of DCT coefficients constituting the filtered information signal.