In this chapter, we covered a new genre of image processing algorithms. Moving from performing per-pixel computations, we introduced the notion of aggregating pixel values into structures called histograms.
Delving into the details, you learnt about the nomenclature associated with histograms and also went through the implementations of histogram-related routines available in OpenCV. We also briefly touched upon the idea that a histogram acts as a form of representation or descriptor for images. In fact, histograms are one of the simplest forms of image descriptors that are used quite extensively in computer vision literature. We will look at descriptors in much greater detail in the subsequent chapters of the book.
If you recall, at the beginning of the book, we made a distinction between image processing and computer vision algorithms. Note that in all the programs we have developed in this chapter, none of the outputs were images. We might have used an image to represent the plot...