Lecture 4: Images in IDL

An image is just a 2-D data set BUT

• Images are (usually) bigger, perhaps several hundred data points in each direction.
• Images are (usually) of type byte. This means that each pixel can have only 256 values.

...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.