Chapter 6 introduced discrete image transforms, which are based on sinusoidal and rectangular basis functions. The basis functions of these block transforms span the width of an image block. In other words, all the basis functions have the same fixed support. When it is required to capture transient behavior of a time-domain signal or spatial activity in an image, conventional transform techniques, such as the Fourier transform, are not adequate. The wavelet transform described in this chapter has its basis functions that have varying width instead of fixed width. This feature of varying width makes the wavelet transform, a powerful tool for signal analysis in general and image processing in particular. ...