As usual with your post's sir, I think this is a fascinating idea.

The question is, could the silver in the film be read by a magnetic head, akin to magnetic tape?

From a historical perspective, how did the earliest "electronic" cameras operate? Surely some of you have seen this.... http://www.retrothing.com/2008/05/kodaks-first-di.html

Your propsal raises an interesting question.... what ways are there to record an image, in a camera, electronically, without it being digital? Afterall, video was analog for 50 years or so, and recorded onto magnetic tape.

An interetsing proposition as usual Umut!