Chromostereopsis — depth from color

Drop an image to convert it

Procedural ChromaDepth scenes

Every pixel is colored only by its distance. No shading cue is needed for depth; shading is optional.

Scene

Animate Space

Speed

Zoom

Density

Point size

Depth curve

Relief shading Auto-fit color range to depth High resolution

Drag to rotate, wheel or pinch to zoom, double-click to reset. Keys 1–0 pick scenes.

Original random-dot ring stereogram

The program from the scirealm.org page. It scatters 2^N random points over the square [−1, 1]². A point whose radius falls in ring 1 is red, in ring 2 blue (red wins where the rings overlap), and anywhere else it takes the background grey, which also erases earlier dots.

Example

SizePoints

NumPoints

radMin1

radMax1

radMin2

radMax2

BGcol

SwitchColors S Redraw continuously (twinkle)

FantasticRedBlueScene is the image from a LinkedIn conversation shown on the original page: red maple leaves float in front of a blue night sky and moon. Try it in Your image too, with SwitchColors-style swapping.

Ring 1 = red (radMin1–radMax1), ring 2 = blue (radMin2–radMax2), radii in units of the half-width. Coordinates in the readout use the original 600 × 600 canvas.

Classic two-color patterns

The flat figures where chromostereopsis was first noticed. Uses the two ends of the color scale.

Pattern

Text

Scale

Look from 1–2 m in a dark room. If the colors refuse to separate, try Swap colors or a white background; some people see the depth reversed.

Convert an image

Load a picture and color it by depth. Without a depth map, brightness stands in for nearness.

Or drop / paste an image onto the canvas. Depth maps: white = near.

Depth from

Smoothing

Contrast

Keep detail

Why it happens

The eye's lens bends blue more than red. With each pupil slightly off the visual axis, the red and blue images land at different places in the two eyes, and the brain reads that as stereo disparity.

Pupil offset

Near color λ

Far color λ

Eye spacing

View distance

Exaggerate

Pupil offset in mm from the eye's achromatic axis; + is the usual direction (red in front). Refraction vs. wavelength uses the Thibos et al. (1992) "chromatic eye" model.

Which way do you see it?

Most people see red in front on black. Some see the reverse, and many flip on a white background. Use both eyes, about 1 m away.

Try one eye closed: the effect should mostly vanish, showing it is binocular.

Quick facts

Known since the 1800s; Einthoven (1885) tied it to the eye's chromatic aberration.

The eye's focus differs by about 2 diopters between violet and deep red.

ChromaDepth glasses add a much larger, controlled color-dependent disparity, so the full spectrum stacks into layers: red, orange, yellow, green, blue.

Painters' rule of thumb: warm colors advance, cool colors recede.