| Summary: | 碩士 === 國立中興大學 === 機械工程學系所 === 100 === The technology of computer vision is broadly applied in industry such as industrial inspection，3D surface profilometry.Analyzing the images provided by camers ,the world coordinate can be obtained to reconstruct a 3D contours.if the more lower of images distortion the more useful information can be used,and then get more accurate measurement data.At the same time,CCD camera lens distortion or the lack of measurement accuracy of the instrument itself or interference with the external environment,those cases often will make errors on the measurement results,and we start to calibrate them in many ways. The camera calibration is the first step,and then we also have to calibrate brightness of structure light,that we can use hybrid structure light coding to make measurement.
This paper describes Camera Calibration and 、Hybrid Structure Light Coding(Phase Shifting and Gray Code) and γ(Gamma ) correction,By Zheng’s Camera Calibration method,we can calibration camera’s exterior constent and interior constent,we use the liquid crystal display (LCD) which projects the fringe projection,and try to correct LCD projector projecton and image grabbing which result the nonlinearity of the VGA display card, there is always a Gamma correction for LCD or some display equipment to accommodate the human’s visual system,but sometimes the correction will makes brightness nonlinear problem and influences the phase accuracy,so this paper use the Levenberg-Marquardt’s method to solve non-linear least squares problem to find the best γ(Gamma ) valeue.we also analyze difference between before and after of γ(Gamma ) correction that by hybrid structure light coding projection.
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