Lossless Image Compression using Proposed Equations and JPEG-LS Prediction

This paper proposes a new lossless image compression technique which makes use of simple mathematical equations along with Joint Photographic Expert Group Lossless (JPEG-LS) prediction technique to compress the image. Context of four pixels is used and the four pixels are varied in their signs which constitute a system of sixteen equations. Among the four context pixels, three pixels are actual pixels whereas the fourth pixel is the predicted value of the current pixel. Equations are solved to obtain the equation which result in minimum positive equation. Having obtained the minimum positive equation, it is solved by replacing the predicted pixel by the actual pixel value. Resulting absolute value is written in the image which results in transformed image and the sign of the result is written in a file. Both the transformed image and the sign file are Huffman encoded to reduce their size further. Compression ratio achieved for Lena image using the proposed compression technique is 1.6.