change the opacity of a specific point of the image in Android programming

问题

I want to select a point from the image shown in an image view and only reduce the opacity of the image at the same point without changing the opacity of the image elsewhere. How can I do this?

来源：https://stackoverflow.com/questions/61697699/change-the-opacity-of-a-specific-point-of-the-image-in-android-programming