Subjective rating of picture coding algorithms

This paper reports on a comprehensive subjective evaluation of different waveform coding algorithms for monochrome still pictures. In order to obtain reliable and relevant results about the coding efficiency in the sense of a rate-distortion criterion, i.e. mean opinion scores (MOS) of observers vs. bit rate, the coding algorithms are optimized as far as possible by maintaining the subjective quality of coded pictures. Test pictures with various bit rates are generated from several source pictures. The psychophysical picture quality experiments are carried out for the whole set of test pictures. Based on the experimental results, different coding algorithms are quantitatively compared with each other. The coding methods investigated include the following stand-alone methods: DPCM, vector quantization (VQ), discrete cosine transform (DCT) coding, recursive block coding (RBC), subband coding (SBC), wavelet transform coding (WTC), Laplacian pyramid coding, Cortex transform coding, and combined methods: ISO standard JPEG, wavelet transform with run-length coding and variable length coding, DCT with pyramid vector quantization (PVQ) and subband transform with PVQ.