概要

Recently, the 3D measurement of moving objects becomes an important task in various applications. The potential applications are medical application, multimedia, crash testing, fluid analysis and so on. For these applications, the 3D measurement is required to have properties of high accuracy, high frame-rate, and high density. We have proposed a method based on a projector-camera system that reconstructs a shape from a single image where a static pattern is cast by a projector. The proposed method realizes one-shot 3D reconstruction with a single-colored pattern that consists of vertical and horizontal sinusoidal curves. It finds correspondences in sub-pixel accuracy between projector and camera by using the information implicitly encoded in the grid of wave lines. The reconstructed shape is optimized by interpolating grid patterns to reconstruct dense shape to achieve the above requirements. One of the issues to improve this system is to realize 3D reconstruction under external light that disturbs detection of the pattern. We have developed a laser system to generate the wave grid pattern that can be detected by filtering out external light. The pattern is formed by using diffractive optical element to generate the static pattern power-efficiently without temporal scanning. The power-efficiency can contribute to downsizing of the system. We apply the same approach to reconstruct 3D shapes for medical endoscopy that equips the pattern projector at the tip of the probe. In the experiments, we show the effectiveness of the proposed laser pattern projector by reconstructing 3D shapes.