Surface profilometry and projector calibration based on multi-period structured light

• Main Authors: Yu-Tung Chen, 陳昱佟
• Other Authors: 李吉群
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/81270425690764192766

碩士 === 國立中興大學 === 機械工程學系所 === 104 === In the visual system, two-dimensional image is obtain by camera. But it still lack depth information between image and object. If it can get depth (Z) information and point data (x, y) of two-dimensional plane. Then can draw three-dimensional picture to apply in reverse engineering three-dimensional reconstruction. In this study, we build a non-contact optical system by two cameras and a projector. Produce multi-period structured light by computer, then projected onto the object and captured by two cameras. Phase unwrapping based on four-step phase-shifting and multi-period structured light. If got absolute phase, corresponding the absolute phase of the object and camera pixel coordinates. Will know the relationship between point data (x, y) and three-dimensional coordinates. Connected three-dimensional coordinate and point data can be a linear equation passing through the origin of the camera. It can find the projected light plane equation by absolute phase. Calculating the intersection point of the projected light plane equation and the linear equation is the three-dimensional coordinate. The camera and the projector need to calibration before calculating the intersection point. Coordinate system transformation by internal and external parameters. Undistorted image by distortion parameters. Calibration the linear brightness system is one of important. If the projector output brightness and the camera input brightness is nonlinear, when calculating the absolute phase will error.