Comparison of Error Diffusion Block Truncation Coding with Block Truncation Coding Technique

In today's digital world, providing increased data amount in the limited bandwidth is a challenging task. It requires a powerful digital compression scheme to satisfy the vast requirement of users. Block Truncation Coding (BTC) has been used for many years for coding digital images for the purposes of transmission and storage. It uses moment preserving quantization method for compressing digital grayscale images. Even though this method retains the visual quality of the reconstructed image with good compression ratio, it shows some artifacts like blocking effect and false contouring. Various schemes of block truncation coding using digital halftoning techniques like ordered dithering, error diffusion, and dot diffusion have been proposed to improve the quality of BTC. Experimental result shows that as compared to the traditional BTC technique image compression employing digital halftoning i.e Error Diffusion Block Truncation Coding (EDBTC) provided excellent image quality and artifact-free results.