Como Bloquear Aplicaciones En Android

Now, let's say the background in each photo was stationary (maybe a few px of wobble), and I had a photo of the complete background without any figure blocking it. Would there be a way to use the complete background as some sort of inverse/subtractive mask, so all you're left with is the person? At the heart of it, this is about automating the process of removing the same background from every image - so any alternate methods are welcome too. Thanks in advance!