State of the Art Lossless Image Compression Algorithms

There are numerous applications of image processing, such as satellite imaging, medical imaging, and video where the image size or image stream size is too large and requires a large amount of storage space or high bandwidth for communication in its original form. Image compression techniques can be used e ectively in such applications. Lossless (reversible) image compression techniques preserve the information so that exact reconstruction of the image is possible from the compressed data. In this paper we survey existing lossless compression schemes and also present some new techniques such as grayscale mapping and variable bit length coding. Grayscale mapping is a simple technique that can be used to improve the compression ratios achievable by other image compression methods. The variable bit length coding technique developed by us provides greater compression than coding techniques such as Hu man coding and arithmetic coding when applied to several raw images. We also develop a general lossy+residual interpolation technique for image compression. The compression techniques surveyed and developed in this paper are compared using a variety of images.