Lossless image compression with areas of cross-point regions for modeling

This paper presents the scheme of ACRIC (Areas of Cross-point Regions for modeling in the scheme of Image Compression), a scheme for losslessly encoding and decoding images, especially medical images. Developed from the theory of cross-point regions for lossless images compression, ACRIC gives the new theory of cross-point regions to build areas of cross-point regions with using flexible lengths of ideal cross-point regions in entire cross-point regions. Based on the effect of Gray coding on cross points which have grey values around 2ⁿ, the data bits of cross points trend to same states in cross-point regions after Gray coding, so we can optimize the probability of bits in certain areas of cross-point regions for the step of coding in the process of entropy coding. This leads to improving the compression ratio for the scheme ACRIC over the other schemes. The scheme of ACRIC is good for losslessly compressing medical images because of large areas of pixels of approximate grey values.