To most computer systems a grayscale image is just a 2-D data set such as we looked at in the previous lecture, and IDL is no exception. The differences between images and other data sets are simply that:
...and that's all. You can display and process greyscale images just like any other 2-dimensional array. You will find that contour or surface plots of an image of any size are not very useful and take a very long time to draw. In this lecture we look at ways of reading, displaying and processing images in IDL.