Projection pursuit image compression with variable block size segmentation

In this letter, a novel multiresolution algorithm for lossy gray-scale image compression is presented, High-quality low bit rate image compression is achieved first by segmenting an image into regions of different sizes based on perceptual variation in each region and then constructing a distinct code for each block by using the theory of projection pursuit (PP). Projection pursuit allows one to adaptively construct a better approximation for each block by optimally selecting basis functions, The process is stopped when the desired peak signal-to-noise ratio (PSNR) or bit rate (b/pixel) is achieved, At rates below 0.5 b/pixel, our algorithm shows superior performance, both in terms of PSNR and subjective image quality, over the Joint Photographers Expert Group (JPEG) algorithm [3], and comparable performance to the embedded zerotree wavelet (EZW) algorithm [11].