This a small tool which I use to crop images under Linux.

``` Usage: pycrop [options] file

Description:
         This program crops images. You can either pass a concrete image as
         an argument or the program will process all images from the current 
         directory.

         The program uses the tool "convert" from ImageMagic (http://www.imagemagick.org).

Options: 
         -h         : print this help message and exit
         -v         : produce verbose output
         --image    : image file

Keyboard control:
        down        : move the selection down
        up          : move the selection up
        left        : move the selection left
        right       : move the selection right
        +           : zoom in by 5% 
        -           : zoom out by 5% 
        Ctrl +      : zoom in by 1%
        Ctrl -      : zoom out by 1%
        Alt +       : zoom in by 25%
        Alt -       : zoom out by 25%
        Del         : change between landscape and portrait orientation
        Home        : move forward in the list of the preset side ratios 
        End         : move backward in the list of the preset side ratios 
        Enter       : crop the selected image

```