Miss. Rohini N. Shrikhande, Dr. V. K. Bairagi
stract Here, the concept of compression theory and lossless image compression methods are studied. In order to preserve the value of diagnostic medical images, it is necessary to provide lossless image compression. Apart from practical reasons, there are often legal restrictions on the lossless medical image compression. Lossless data compression has been suggested for many space science exploration mission applications either to increase the science return or to reduce the requirement for on-board memory, station contact time, and data archival volume. A Lossless compression technique guarantees full reconstruction of the original data without incurring any distortion in the process. As for the method of compression, predictive compression is much simpler than transformation-based compression, and in addition usually results in lower bit rate. During recent years, several algorithms for predictive lossless image compression have been presented. Predictive algorithms for image compression can be classified in two groups: • The algorithms with a single pass, and • The algorithms with two passes.