Faceswapping
Find out how to face swap!
The following are some observations I have made regarding the art of "faceswapping", a skill that is used primarily in ModRen and mating type contests. A seamless faceswap should give a viewer the uncomfortable feeling of "Oh God! He's so pretty!" instead of, "Oh God! He's a mutant!" I feel the key to a quality image is recognition of the subject. Recognition relies on the proper matching of your source images, using correct alignment, scaling and masking.
At the top are my 2 source images, Marilyn Monroe and Cary Grant, two of my favorites. Notice that the head angle is already close, and unless you are dealing with subjects that only have a few good images, I see no reason to make more work for yourself trying to tweak the images to make the angle look right.
Image A is what I would consider a decent match. The position and scale of the face are appropriate for the underlying head.
Image B, bigface. The face is just too large for the head. To make it fit, the cheeks and chin of the face are masked out, and to some extent the face becomes unrecognizable as Cary. When adjusting the face size, set the transparency of the face to 50% or so. At 50% transparency it is possible to compare the face scale to the face on the underlying head. I use the eyes as a guide for scale.
Image C, benthead. My example is a little extreme, but you get the point. The head is pointing in one direction, and the face another. When positioning the face, look at the head. If you can only see one ear, this is the side of the nose you should see. It is a simple task to mirror the face to match the angle. Most faces can be mirrored and nobody would notice. A word of advice about benthead images...Avoid using base source images that have the head at odd angles relative to the body. It is guaranteed that even with the best blending, the resulting image will look odd when you are done.
Image D, mutantface. Again, to improve recognition, I don't advise mixing and matching eyes, nose and mouth. It's all or nothing. As in my example, the subjects are unrecognizable.
Image E, ET-head. This is when the face is scaled correctly, the head angle is correct, but the face is sitting too far forward on the head. Kinda like ET. If you find yourself doing a lot of cloning between the ears and eyes, there is a good chance you are gonna end up with an ET-head. Set the face transparency to 50% and use the eyes as a guide to align the images.
Avoid these common mistakes, and you will do fine.
