从 OpenCV3.2 开始，生活变得更简单了，您现在可以在一行代码中旋转图像:

As of OpenCV3.2, life just got a bit easier, you can now rotate an image in a single line of code:

cv::rotate(image, image, cv::ROTATE_90_CLOCKWISE);

对于方向，您可以选择以下任何一项:

For the direction you can choose any of the following:

ROTATE_90_CLOCKWISE
ROTATE_180
ROTATE_90_COUNTERCLOCKWISE