transform.py 文件源码

def skew_image(img, angle):
    """
    Skew image using some math
    :param img: PIL image object
    :param angle: Angle in radians (function doesn't do well outside the range -1 -> 1, but still works)
    :return: PIL image object
    """
    width, height = img.size
    # Get the width that is to be added to the image based on the angle of skew
    xshift = tan(abs(angle)) * height
    new_width = width + int(xshift)

    if new_width < 0:
        return img

    # Apply transform
    img = img.transform(
        (new_width, height),
        Image.AFFINE,
        (1, angle, -xshift if angle > 0 else 0, 0, 1, 0),
        Image.BICUBIC
    )

    return img