This is something new for me. But since images are digital, you can create a grid on (x,y) plain according to number of pixels and assigning some value to pixel. If it is black-white image, there is only one value for every pixel (intensity), but for color image it should contain also digital information of color.

If the image is some physical object (for example, water waves on the surface of an ocean), there exist some evolutionary equations and one can study dynamics.

An application in art is something new for me. All depends on smartness of corresponding differential equation.

Thank you to all. I am looking more basic, like how the conversion is happening. ...