code: def _cropbox(self, image, x, y, x2, y2):
          
          image['options']['crop'] = '%sx%s+%s+%s' % (x2 - x, y2 - y, x, y)
          image['size'] = (x2 - x, y2 - y)  # update image size
          return image
docs: Crops the image to a set of x,y coordinates (x,y) is top left, (x2,y2) is bottom left