This document discusses image compression. It defines image compression as reducing the amount of data required to represent a digital image without significant loss of information. The goal is to minimize the number of bits required to represent an image in order to reduce storage and transmission requirements. Image compression removes three types of redundancies: coding, interpixel, and psychovisual. It describes lossy and lossless compression methods and variable-length coding techniques like Huffman coding which assign shorter codes to more probable values to reduce coding redundancy.