I’ve been wanting to try this for sometime, and finally had my setup mostly ready and the right materials. A Lithophane is an image etched into something translucent. In my case I used LinuxCNC, which runs my CNC router, and includes a script called Image-to-gcode, that creates a gcode height map based on the color or light to dark variations in an image. The material I used is 1/2″ Corian.
The original picture is this one of my son at the beach.
This is the lithophane, without back lighting. I used a 30 degree vee bit with a .01″ point to carve this it’s about 4″ wide and 5 1/4″ tall, the pixels are .003″ in size.