Darken Parts Of A Free-hand Cropped Image In Android

I want to add a free hand crop functionality. Till now I can open the picture and draw a path around the part of the image that I want to crop thanks to this code: https://stacko

Solution 1:

Use the following two methods as a start:

setXfermode(new PorterDuffXfermode(Mode.DARKEN)); 
canvas.clipPath(path, Region.Op.DIFFERENCE);

The first one is applied to a Paint object and darkens a certain region. The second "clips" the path in your canvas and takes the inverse (using Region.Op.DIFFERENCE).