Learning OpenCV

Chapter 6. Image Transforms

Overview

In the previous chapter we covered a lot of different things you could do with an image. The majority of the operators presented thus far are used to enhance, modify, or otherwise "process" one image into a similar but new image.

In this chapter we will look at image transforms, which are methods for changing an image into an alternate representation of the data entirely. Perhaps the most common example of a transform would be a something like a Fourier transform, in which the image is converted to an alternate representation of the data in the original image. The result of this operation is still stored in an OpenCV "image" structure, but the individual "pixels" in this new image represent spectral components of the original input rather than the spatial components we are used to thinking about.

There are a number of useful transforms that arise repeatedly in computer vision. OpenCV provides complete implementations of some of the more common ones as well as building blocks to help you implement your own image transforms.