“…In fact, the fractal wavelets constitute the foundation of this class. The old Haar wavelet (also known as the lazy wavelet), as a typical empirical transform, works very well with images, as recently reported in [16,17]. The more sophisticated Walsh-Hadamard Transform (still empirical, though) can also be adapted to process images-see, for example, [18,19] (where it works in combination with Haar wavelet).…”