Abstract:
This paper describes a lossless image compression techniques on colour images with the help of Huffman and CALIC coding. In this approach, an RGB image is first transformed into a gray scale image. In a gray color space, the color components are downsampled and we estimate the value between original image and the downsampled image. These values are substracted from an original counterpart to obtain prediction error. At the decoder end, the exact reverse method is used to obtain the original color image. Mean Square Error (MSE) and Peak Signal-to-Noise Ratio (PSNR) are the two basic parameters used to obtain a good quality image as same as the original image. As compaired to other existing techniques, Huffman method provide a good compression results.
