A system providing methods for improved compression of images that have been compressed using Discrete Cosine Transform (DCT) based compression is described. A digital image that has been compressed using DCT based compression, such as an image compressed using the Joint Photographic Experts Group (JPEG) compression scheme, is received and partially decompressed to generate DCT coefficients of the image. The decoded coefficients of the image are then rearranged to aggregate like frequencies together. After rearrangement, the image is recompressed using a wavelet-based compression scheme.