Application of the DCT and Arithmetic Coding to Medical Image Compression

This paper presents an application of the discrete cosine transform compression technique on medical images of the IRM type. The arithmetic coding method is used to encode the coefficients. The tests of this lossy compression/ decompression technique are performed on two IRM images representing the brain, in axial and sagital views, of a patient suffering from a cerebral hemorhage. The obtained results on these images show that the DCT technique permits to considerably improve the compression rate while mainting a good image quality when threshold varies in the interval: 0 les TH les 20 for bloc sizes: [16times16] and [32times32]. However, a severe degradation of the quality of the reconstructed medical image is observed when the threshold is greater than 30.