Improving LZW Image Compression
Sawsan A. Abu Taleb, Prince Abdullah, Bin Ghazi, Islah K. Gharaybih · 2010
Previous lossless image compression techniques seek the smallest possible image storage size for a specific level of image quality; in addition, dictionary-based encoding methods were initially implemented to reduce the one-dimensional correlation in text. This paper proposes improving compression method which uses a bit plane slicing and adaptive Huffman with a Lempel-Ziv-Welch (LZW) dictionary. When LZW compression used to compress image, the limitation of the type of image and the number of colors must be considered and LZW compression will be used for some cases. The limitation will be decreased by using bit plan slicing for colored and gray scale images. The compression ratio of proposed method is better than the standard LZW method by 55.6% for colored image, and 102% for gray scaled images. Experimental results for the proposed method outperform the existing methods for a large set of different type of images.