The composition of every piece of artwork (including photographs, drawings, paintings, etc.) can be broken into a series of value blocks of light, medium, and dark. This program generates every single combination of light, medium, and dark squares in a 3x3 grid, so every piece of artwork can be approximately classified using this program.
The program does not handle user input, so the user is limited to light, medium, and dark grays. The user also cannot choose the size of the grid (except by hardcoding it in the ref variable in calc.js.
The grids can only be square, and must all be the same size.
Download the .zip file for this program from the green "code" button: click this button, go to the "local" tab in the popup, and click "Download ZIP." Unzip this to a new folder on your machine (right click and choose "extract all," then pick a destination. Navigate to the unzipped folder and click on calc.js. If asked, choose a browser to run this program on (Chrome preferred.) No user input is needed. Enjoy :)