During the last decade, a number of signal processing applications have emerged using wavelet theory. Among those applications, the most widespread developments have occurred in the area of data compression. Wavelet techniques have demonstrated the ability to provide not only high coding efficiency, but also spatial and quality scalability features. In this chapter, we focus on the utility of the wavelet transform for image data compression applications. 8.1 REVIEW OF THE WAVELET TRANSFORM 8.1.1