Adaptive image compression using Adaptive Huffman and LZW

In this digital era, the need of storing data has increased rapidly. This circumstance is proportional to the size of files and their storage. In order to decrease the required big size of storage, the file size should be reduced by still considering the quality of the respective data. This can be done by implementing a compression algorithm, such as LZW. In this paper, we propose the pre-processing step which is used before the file is being compressed. This step includes bit selection by using mean, median, and mode for adaptively determining the number of replacing bits. According the experimental result performed to the standard test images, we are able to achieve 36.26 dB of PSNR and 2.9 of compression ratio.