def crop(im, slices=(slice(100, -100), slice(250, -300))):
    """Crop an image to contain only plate interior.

    Parameters
    ----------
    im : array
        The image to be cropped.
    slices : tuple of slice objects, optional
        The slices defining the crop. The default values are for
        stitched images from the Marcelle screen.

    Returns
    -------
    imc : array
        The cropped image.

    Examples
    --------
    >>> im = np.zeros((5, 5), int)
    >>> im[1:4, 1:4] = 1
    >>> crop(im, slices=(slice(1, 4), slice(1, 4)))
    array([[1, 1, 1],
           [1, 1, 1],
           [1, 1, 1]])
    """
    return im[slices]
