SVD based linear filtering in DCT domain

Efficient linear filtering in DCT domain is important in the area of processing and manipulation of image and video streams compressed in DCT-based method. In this paper, we proposed a novel method for linear filtering in DCT domain, regardless of filter type. We decompose any filter by SVD into weighted separable sub-filters which are well studied. Then we do fast linear filtering using these separable subfilters in DCT domain, and combine their results. To our best knowledge, it is the first method capable to do linear filtering with any type of filters directly in DCT domain. The scheme is demonstrated and discussed by doing Gabor filtering in DCT domain. Experiment results show that convolution result using the proposed solution is the same as that in spatial domain. Furthermore, our scheme is well suitable for distributed computing, which will improve computing speed greatly.