File & Image Uploader Pro allows you to crop your images prior to upload to fit to a desired size. To achieve this, both resizeWidth and resizeHeight has to be set to an integer greater than 0.
Setting only one parameter, will lead to image resizing.
The following JSON snippet in the transformation parameters attribute will crop all of your images to fit in a 64 x 64 px square.
{"resizeWidth":"64", "resizeHeight":"64"}