Crops an image.
object $image: An image object. The $image->resource, $image->info['width'], and $image->info['height'] values will be modified by this call.
int $x: The starting x offset at which to start the crop, in pixels.
int $y: The starting y offset at which to start the crop, in pixels.
int $width: The width of the cropped area, in pixels.
int $height: The height of the cropped area, in pixels.
bool TRUE or FALSE, based on success.
function crop($image, $x, $y, $width, $height);