By default, it makes a guess as to what the background color is. You can override the default with the -white and -black flags.
The options -left, -right, -top and -bottom restrict cropping to the sides specified. The default is to crop all sides of the image.
All flags can be abbreviated to their shortest unique prefix.
Created by unroff & hp-tools. © by Hans-Peter Bischof. All Rights Reserved (1997).
Last modified 21/April/97