The title may seem a bit off, but I’m looking for a way to take a picture of a player’s character (Live) and crop it within game to get a circular looking profile player picture like we seen on the Roblox website and the Dev forums.
If your UI has a background, you can make an overlay UI element that’s simply the background color with a circular transparent hole in the middle, and place it on top of the character portrait. This will simulate trimming the portrait.
However if you want the portrait itself to have a transparent background, unfortunately there is no way to do this.