pypher.py 文件源码

def trim(image, shape):
    """
    Trim image to a given shape

    Parameters
    ----------
    image: 2D `numpy.ndarray`
        Input image
    shape: tuple of int
        Desired output shape of the image

    Returns
    -------
    new_image: 2D `numpy.ndarray`
        Input image trimmed

    """
    shape = np.asarray(shape, dtype=int)
    imshape = np.asarray(image.shape, dtype=int)

    if np.alltrue(imshape == shape):
        return image

    if np.any(shape <= 0):
        raise ValueError("TRIM: null or negative shape given")

    dshape = imshape - shape
    if np.any(dshape < 0):
        raise ValueError("TRIM: target size bigger than source one")

    if np.any(dshape % 2 != 0):
        raise ValueError("TRIM: source and target shapes "
                         "have different parity")

    idx, idy = np.indices(shape)
    offx, offy = dshape // 2

    return image[idx + offx, idy + offy]