photo editing app are these functions possible?

Answer 1

The targetting part can be easily done in 3.1, you’ll simply set a view with a transparent body image as the custom camera view (setCameraOverlayView docs). The body outline will only be visible in the view finder, not on the photograph. Once you have the image aligned, you can then separate the body image from the background using a PNG mask image with an alpha channel. This image would only show the parts that fall inside the body outline, and you can also have a decent feather on the border. I am just not sure about the quality of the resulting image, the aligning is bound to be pretty imprecise.