Sharpen images at the command line

If you followed Tip 154, on page 197, and Tip 11, on page 72, you'll already have come into contact with Imagemagick. This command-line program can do just about anything to images and you can learn more about it by viewing its man page (man imagemagick) or viewing its website Perhaps one of the most useful functions it can perform, besides file format conversion and resizing, is to sharpen an image. Almost all images look better when sharpened, particularly if they're being shrunk for use in...