Enhanced Min-Max Procedure based on Block Truncation Coding for Image Compression

In this paper, we have proposed a method based on Block Truncation coding (BTC) for image compression. The existing Min-Max procedure based on BTC is enhanced to further improve the quality of the reconstructed images. Images are decoded using three quantization levels by extending the size of the bitplane. The three quantization levels being Minimum, Maximum and the average of both are preserved for each block. Experiments were carried over standard images like Lena, Cameraman, Boats, Bridge and Baboon. For all images, the proposed method outperforms the existing method in terms of PSNR values.