ABSTRACT
The topic of visualization was introduced in the previous chapter, together with visual encodings appropriate for a wide range of types of data. For many visualization applications, the main challenge lies in finding the appropriate spatial mapping of the data, but in other cases the data comes with a natural mapping. For instance, a photograph is a set of measured data that has an obvious visualization: simply display it on the screen. However, other ways of displaying the data may be useful as well, depending on what the user is trying to learn from it. An X-ray radiograph used to diagnose a broken bone is another example of a 2D image that is normally displayed directly.
