Block truncation coding using edginess information
An improvement of the well-known block truncation coding (BTC) method, introduced by Delp and Mitchell (1979), is proposed. The basic idea, derived from previous work of Beghdadi and Le Negrate (1989, 1991) on contrast enhancement and image filtering using a local contrast measure is to exploit edginess information in estimating both the quantization threshold and the reconstruction levels. The results obtained on actual images clearly show the efficiency of the method in preserving edge information compared to similar approaches.