Compressed pattern matching in JPEG images

Summary form only given. We concentrate on two-dimensional compressed matching in which the given encoded text is an image encoded by the standard JPEG baseline scheme and the pattern consists of a image fragment we are looking for. Baseline JPEG uses a static Huffman code, without which compressed matching would not always be possible, since our underlying assumption is that all occurrences of the pattern are encoded by the same binary sequence. The compressed matching starts by encoding the pattern using the same JPEG algorithm as the one used for the original image. The search process has to be repeated for each matching attempt.