A Comparative Study of Various Approaches to Lossy Image Compression Process

An image is a 2D signal processed by the human visual system. The signal representing images are usually in analog form, but for processing, storage, transmission, and computing by computer applications, analog images are converted from analog to digital form. A digital image is a 2D array of pixels. Digital images are used in medical science, security techniques, and in transmission of data, for storing memories and for many purposes in human life. Digital image consumes storage in digital devices, as well as the size of image, may cause problem for transmission of digital image over a network, hence we need some compression method to reduce image size with respect to storage. This paper presents a comparative study of different type of lossy image compression approaches which varies on parameters such as mathematical transformation, quantization, and round-off factor (in n-MM method).