Free lithophane maker: turn a photo into a printable STL

How a 2D photo becomes 3D without AI

A camera flattens the world, so a single photo stores colour but no distance. Your brain still sees depth in it, because it reads cues that have nothing to do with stereo vision. This tool reads the same cues, mixes them into a depth map in which white is near and black is far, then raises a mesh of tens of thousands of points by that map and renders it with WebGL.

1. 1

   Height in the frame

   In most scenes the ground recedes towards the horizon, so the lower part of a picture tends to be nearer.

2. 2

   Focus

   Cameras usually focus on the subject. Areas with fine, sharp detail are treated as nearer than soft, blurred ones.

3. 3

   Aerial perspective

   Air scatters light, so distant hills and buildings look paler, bluer and lower in contrast. Hazy areas are pushed back.

4. 4

   Colour strength

   Saturated colours tend to belong to near objects. Faded colours tend to be far away.

5. 5

   Figure and ground

   Colours that touch the border of the image and connect to it are treated as background, so a subject on a plain backdrop separates cleanly.

6. 6

   Edge snapping

   A guided filter aligns the depth map with edges in the photo, so the depth steps happen on outlines instead of smearing across them.

7. 7

   Shape from silhouette

   Round out shapes inflates the subject from its outline with a distance transform, turning a flat cut-out into a rounded form.

Each depth method weights these cues differently. Landscape leans on height in the frame and haze. Subject leans on figure and ground and then rounds the subject out. Light is near and Dark is near skip the cues and use brightness directly, which is what you want for logos, coins, engravings and lithophanes.

What you can make with it

• 3D photos for social posts. Record the video loop for a parallax clip like the 3D photo effect on social apps, from any picture.
• Lithophanes. Print a photo in white filament that shows the picture when light shines through it, for lamps, night lights and gifts.
• Reliefs, signs and stamps. Turn a logo or line drawing into a raised STL for 3D printing or CNC carving.
• Red-cyan anaglyphs. Save a snapshot in Red-cyan 3D view and look at it through cheap paper 3D glasses.
• Assets for 3D scenes. Drop the GLB into Blender, a game engine or a web page as a textured backdrop.

Tips for a better result

• Set the focus plane on your subject, so it stays still while the background moves around it.
• Keep the depth amount low for 3D photos. Around 20 to 30% looks natural; more stretches the edges.
• If the sky comes out near, switch to Landscape or paint it back with Push back.
• For portraits, Subject with Round out shapes at 60% or more gives faces and bodies volume.
• For prints, check the Clay view: it shows the shape without the photo, the way the printer sees it.

Lithophane maker questions