At this point, you should have gained a good understanding of color models, the Fourier transform, and several kinds of filters that have been made available by OpenCV to process images.
You should also be proficient in detecting edges, lines, circles, and shapes in general. Additionally, you should be able to find contours and exploit the information they provide about the subjects contained in an image. These concepts are complementary to the next chapter's topics – namely, the segmentation of an image according to depth and estimating the distance of a subject in an image.
