Determination of frequency sensitivities for perceptual subband image coding

A method for determining the visibility thresholds for a given subband system is introduced. The approach identifies the important worse case combination of the quantisation error in each basis function and determines the corresponding visibility thresholds using results previously measured in the DCT domain. Using the proposed method it is relatively simple to determine the visibility thresholds for any subband system in any colour space. Simulation results on the lapped orthogonal transform (LOT) show that the visibility thresholds are useful in visually lossless coding and perceptual weighted quantisation