Integrated task-specific wavelets and best-basis search for image compression

4 Integrated task-specific wavelets and best-basis search for image compression 

As stated in the previous section, optimal wavelet image compression can be achieved by integrating the process of wavelet construction with best-basis search. The best-basis search using a standard off-the-shelf Coifman wavelet (Nf = 2) for four levels is shown in Fig. II. In this case the threshold cost function used was simply the constant value 0.2. The resulting compression ratio obtained was 9.50. 

The authors would like to thank Dr S. Aeberhard for generating the results for the integrated task-specific wavelet construction and best-basis search. 

Witten, R. Neal and J. Cleary, Arithmetic Coding for Data Compression, Computer Practices, 30 (1987). 520-540. 

Ziv and A. Lempel, A universal algorithm for sequential data compression, IEEE Transactions on Information Theory, 23 (1977). 337-343. 

---