Robust Structured Light Pattern for Use with a Spatial Light Modulator in 3-D Endoscopy

This article introduces a novel structured light pattern designed to be compatible with the spatial light modulator (SLM) projection. The proposed pattern is a De Bruijn-based sequence applied to a combination of continuous and dashed lines for the pattern. The sequence is coded in the period and duty cycles of the dashed lines. It provides 16 different lines which limits to two the required number of dashed lines needed for identification. The segmentation has been made easier by alternating continuous and dashed lines. As required by the use of SLMs, the sequence has been adapted by making it symmetric. It has been improved by guaranteeing a hamming distance equal to two for two successive dashed lines. The implementation on a virtual model has shown that a subpixel accuracy has been achieved. This pattern has been developped for 3-D endoscopy.