Approximate convolution using DCT coefficient multipliers
Neri Merhav, R. Kresch · IEEE Transactions on Circuits and Systems for Video Technology · 1998
We develop a method for designing discrete cosine transform (DCT) coefficient multipliers in order to approximate the operation of two-dimensional (2-D) convolution of an image with a given kernel. The method is easy to implement on compressed formats of DCT-based compression methods (JPEG, MPEG, H.261) by using decoding quantization tables that are different from the encoding quantization tables.