ADAPTIVE EDGE-BASED PREDICTION FOR LOSSLESS IMAGE COMPRESSION by Rahul G. Parthe The increasing use of images in a variety of applications has heightened the need for methods to compress an image. Image compression is needed in efficient management of the two main resources in computing systems; space and communication time. Computer based data compression has been practiced for decades and image compression has been studied since the 70's. Thus compression algorithms are slowly approaching their theoretical limit. Image data modeling in particular, is very difficult due to the higher order correlations that exist in natural continuous images. Though the established compression results are hard to surpass, there are some aspects that can be considered to achieve better performance. The gain might appear small, but still significant, especially when considered from the viewpoint of increasing image size of available images. Prediction based image compression is generally a two-phase process: the first phase is the prediction process/method, and the second is the error modeling and encoding. Prediction is done based on the previously encoded data [15], which gives information about the local characteristics of the image area using some non-adaptive fixed rule set. The simplest technique used as a predictor is the Differential Pulse Code Modulation (DPCM) [16], which assumes the prediction for the current pixel to be the value of the previous pixel in raster scan. The error generated for encoding is thus calculated using the difference Image Adaptivity: It is important to first identify and classify the image areas into edge and non-edge areas, so that each can be treated differently [31]. Once the pixels are designated and separated into two classes, a predictor suitable for the class and local image characteristics can be applied. An approximate model of the activity around the pixel to be predicted can be adaptively generated and used to better tune the predictor for the current