Abstract: In the age of information explosion nowadays, image compression is one of the key technologies to promote the further development of multimedia technology. Due to the unique advantage of discrete cosine transform (DCT) in image compression and coding, it is widely extended and applied. This paper describes a DCT-based JPEG system, and analyzes the distribution of one-dimensional DCT and two-dimensional DCT pros and cons before and after transformation coefficients band from a mathematical point of view. And then using Matlab simulation software to simulate the fast-FFT algorithm and the DCT matrix transform algorithm, simulation results show that the DCT transform in image compression has the advantages of easy to implement and flexible, easy to operate and high compression quality.

Key words: DCT transform, image compression, JPEG, Matlab