This is an area of research called natural image matting that has been going on for over 20 years. Some influential papers include: https://www.microsoft.com/

This is an area of research called natural image matting that has been going on for over 20 years. Some influential papers include: https://www.microsoft.com/en-us/research/wp-content/uploads/2016/02/poissonmatting_siggraph04.pdf https://www.microsoft.com/en-us/research/wp-content/uploads/... https://webee.technion.ac.il/people/anat.levin/papers/Matting-Levin-Lischinski-Weiss-CVPR06.pdf https://webee.technion.ac.il/people/anat.levin/papers/Mattin...