[Opencv-python] cv2.sqrt(...) Square root of picture

1. Background

For detailed documentation, please refer to official information.
This blog is as simple and clear as possible. If there are any errors, please correct me.

The python and cv2 versions of this blog are as follows:

#python版本：
3.7.10|packaged by conda-forge|(default,Feb 19 2021,15:37:01)[MSCv.1916 64 bit(AMD64)]
#opencv-python版本：
opencv-python:4.5.1.48

opencv provides the api for taking the square root of the picture:

cv2.sqrt(