Does anybody have a suggestion for a java library that performs automatic cropping and deskewing of images (like those retrieved from a flatbed scanner)?
ImageMagick can do that; you can use the ImageMagick Java bindings. The auto-crop operator is probably what you're looking for. Automatic deskewing is a much harder problem and involves some significant image processing; I'm not sure if ImageMagick can handle that. If you can figure out the skewing parameters using something else, ImageMagick can definitely unskew it for you.