Identification of dominant coefficients in DCT image coders using weighted vector quantization

We propose a method to identify the dominant coefficients in DCT image coders at a very low rate. The method consists of applying a weighted vector quantization technique to a binary-valued matrix in which the 1´s indicate the positions of the dominant DCT coefficients. In this technique the distortion measure is inversely proportional to a weighted number of coincident 1´s, where larger weighting factors are assigned to coincident 1´s in the low-frequency region. Simulation results show that only 0.16 bit/pixel is sufficient to identify the dominant DCT coefficients in a fixed rate scheme, without any significant degradation of the reconstructed image