A device and a method for encoding an image and corresponding decoding method and decoding device

摘要

A method for encoding an image represented in a perceptual color space, wherein the image has at least a luminance component (L) is disclosed. The method comprises:
- transforming (20) by a wavelet transform the luminance component (L) to form at least one low frequency subband of wavelet coefficients;
- reconstructing (22) a low frequency component for at least one spatial area of the low frequency subband;
- subtracting (24) the reconstructed low frequency component from the wavelet coefficients of the spatial area;
- quantizing (26, 28) the wavelet coefficients of the spatial area responsive to the threshold, the threshold being proportional to the reconstructed low frequency component of the spatial area; and
- encoding (30) the quantized wavelet coefficients and the low frequency component.