| Abstract: | A great number of data associated with visual information requires usage of the popular DCT (Discrete Cosine Transform) compression. This also suggests the investigation of methods for image processing directly in the DCT domain. This paper presents a fast DCT domain image up conversion algorithm, and a DCT domain linear filter, which only involves matrix manipulations. By using the separate property of certain spatial filters, we accomplish the DCT domain up conversion via only matrix products. Because 1) most of the matrices can be calculated beforehand, and 2) common DCT blocks are very sparse; and 3) by avoiding the conventional decode and re encode scheme, the computational complexities are greatly reduced. Experiments on real images show good results. |
