This invention relates to a total phase cosine double orthogonal transformation method, in which, the transformation is defined as [F]=[A][f][AT] and the counter-transformation is defined as [f]=[A-1][F][(A-1)T], the improvement to JPEG is to use total phase cosine double orthogonal transformation to replace 2-D scatter cosine transformation to simplify the quantum list so as to save the computation time and increase the quality of re-setting up images and code compress ratio to suit different needs including: inputting an original image and the bit rate to be divided into 8x8 pixel blocks to carry out total phase cosine double orthogonal transformation, the quantum interval is determined based on the bit rate and the transformation coefficient is further equalized, the forecast coding of the DC coefficient and the scan of the AC coefficient, the variable length codes, Huffman entropy coding and outputting the bit sequence of the compressed images, at the receiving end, the re-built image can be got by total counter phase cosine double-orthogonal transformation after Huffman entropy decoding, the variable-length decoding of DC and AC coefficients and counter-quantization. |