Improving LZW Compression
Amit Makkar, Gurjit Singh, Rajneesh Narula · 2012
Earlier lossless image compression techniques try to find 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 block truncate compression algorithm 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 better the existing methods for a large set of different type of images.