Coded Structured Light

Structured light is similar to coded light in that this technique also uses a projector and an off-axis camera. It takes measurements using a series of images with changing fringe patterns. There are many potential fringe patterns to use, but binary and sinusoidal patterns are the most common.

When a series of images are captured of binary patterns of increasing frequency, each position in the camera will have a binary code with a depth relative to the number of images used. The patterns are designed so that any unique binary code at a given camera position will correspond uniquely to a location in space.

A series of phase-shifted sinusoidal patterns can then be projected to determine the phase of a position relative to the frequency of the sinusoidal pattern. In conjunction with the binary encoded coarse position, the phase position can provide a much higher resolution to the final measurement.

Watch how coded structured light works here —