Patent Document ID: 9681140
Application ID: 14970763
Patent Status: 1

Claim One:
1. A method for encoding an image represented in a perceptual color space, wherein the image has at least a luminance component, the method comprising: transforming by a wavelet transform the luminance component to form at least one low frequency subband of wavelet coefficients; determining a low frequency component from the wavelet coefficient(s) of at least one spatial area of the low frequency subband; quantizing and inverse quantizing said determined low frequency component to obtain a reconstructed low frequency component {circumflex over (L)} lf for the at least one spatial area; subtracting the reconstructed low frequency component from the wavelet coefficients of the spatial area; quantizing the wavelet coefficients in the spatial area responsive to a threshold, wherein said threshold is proportional to the reconstructed low frequency component {circumflex over (L)} lf ; and encoding the quantized wavelet coefficients and the low frequency component.