Introduction
An image is composed of pixels of different values (colors). The distribution of pixel values across an image constitutes an important characteristic of that image. This chapter introduces the concept of image histograms. You will learn how to compute a histogram and how to use it to modify an image's appearance. Histograms can also be used to characterize an image's content and detect specific objects or textures in an image. Some of these techniques will be presented in this chapter.