Silhouette animation

This is probably a very elementary question, but I know NOTHING about AI animation. If you look at my Reddit header, you will see a priest standing in front of a window. I would like to animate elements of this and use that for my website headers. So part of that animation would be the priest. The problem I anticipate is that the AI animation will see the silhouette as a blob rather than a person. So, is this concern justified? What would be a good app (hopefully free) to use for this?