Abstract: A new subband coding scheme is proposed in this paper. The two main functions in such schemes, which are the decomposition and quantization, are entirely based on the psychovisual aspects. The visual subbands have been estimated by using the variation of the masking function. These masking effects in the case of sinusoidal gratings show that the peripheral part of the visual system may be modelled by a set of sixteen filters and a low frequency residue. The quantizers associated to such a decomposition have been designed by a methodology which has been developed. The main finding of the conducted experiments is that the decision thresholds and the reconstruction follow a linear law, with an interval quantization varying with frequency and orientation. This result, highly dependent on the way the signals have been characterized, justifies the choice of the local band-limited contrast. The results, obtained with a coding scheme which includes these basic features of the visual system, show that a low signal to noise ratios the visual quality of the reconstructed image reminds much better than for the 'classical' schemes. Another particularity of the approach lies in the structure of the reconstruction image error. Indeed the latter is found to be highly correlated to the structure of the original image.!8
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