Full-frame entropy coding for radiological image compression

The discrete cosine transform (DCT) type algorithm is a leading technique in irreversible image compression. The full-frame bit-allocation (FFBA) technique based on DCT has been proven to be an outstanding compression method for radiological image. A new version of this technique, which discards the bit-table and uses entropy coding instead of bit-packing, FFEC, has recently been developed. The results showed that the new method improves compression ratio by a factor of two (e.g., 24:1 vs. 13:1) with a controlled mean-square-error. With the same compression ratio, the FFEC produces about 50 less error than does FFBA. The FFEC has been tested and results are demonstrated in this paper along with FFBA and the splitting and remapping method. This new method is characterized as a simple, error controllable, and highly efficient compression technique.