The specific implementation effect is to be able to update the rectangle and add text on the rectangle border. I tried to draw the rectangle by setting pixel points before, but couldn’t update the last drawn shape. Then, I thought of setting a transparent window and drawing the rectangle in this window, but because the documentation in the pywin32 library is too difficult to read, I wanted to search for the answer online.

The implementation effect is as smooth as OpenCV obtaining camera videos and drawing images on them