> "You would never matrix multiply an image onto another vector."
That wasn't me. But I can still elaborate: while you can certainly consider a non-color image as a matrix, the operation of multiplying this matrix with a vector is rather meaningless.
While a lot of things can be made into or viewed as matrices, a matrix is typically only meaningful as a representation of a linear map.
> You can certainly apply projections to images, I mean this is what photoshop does.
What's the relationship of this to anything in the comment you replied to?