Spatial Domain Image Transforms
In the material presented in Chap. 5 we looked at a number of geometric processing operations that involve the spatial properties of an image. Averaging over adjacent groups of pixels to reduce noise, and looking at local spatial gradients to enhance edge and line features, are examples. There are, however, more sophisticated approaches for processing the spatial domain properties of an image. The most recognisable is probably the Fourier transformation which we consider in this chapter, allowing us to understand what are called the spatial frequency components of an image. Once we can use the Fourier transformation we will see that it offers a powerful method for generating the sorts of operation we did with templates in Chap. 5.