Are you talking about photographs or individual frames of a film? Photographs can be called pictures or images. If you are talking about individual frames from a movie, we call them frames, but they can also be called stills, still photos, or still images. You hear still pictures less frequently, but I that term is also acceptable.

Films are sometimes called "motion pictures", so people sometimes call them "pictures" for short.

I was analyzing film by literary elements, when I read some of book references, they sometimes used picture or image to explain part of film elements. therefore, these make me confused. thanks for your kindness to help me. :))