Two Dimensional Transforms

Abstract

In this chapter we will briefly show how the discrete wavelet transform can be applied to two dimensional signals, such as images. The 2D wavelet transform comes in two forms. One which consists of two 1D transforms, and one which is a true 2D transform. The first type is called separable, and the second nonseparable. We present some results and examples in the separable case, since it is a straightforward generalization of the results in the one dimensional case. At the end of the chapter we give an example of a nonseparable 2D DWT based on an adaptation of the lifting technique to the 2D case.