基于圆点标定板映射的投影仪标定

Projector Calibration Based on Dot Calibration Plate Mapping

针对投影仪作为结构光的主要组成部分存在无法直接成像存在标定困难精度低的问题,提出一种基于圆点标定板映射的投影仪标定算法。首先,通过编解码将标定板映射到投影仪视角;其次,对灰度图做图像恢复与增强,进行自适应阈值分割后根据标定板形态特征提取出外部轮廓并判断方向;然后,对椭圆标志点进行亚像素边缘识别并对中心坐标排序;最后,通过正视投影变换进行圆心纠偏。实验结果表明,该方法标定过程简单,标定精度高,投影仪的重投影误差可达0.065 pix。

As the main component of structured light,projector is difficult to calibrate and has low precision because of its inability to image directly.Aiming at the above problems,this paper proposes a projector calibration algorithm based on dot calibration plate mapping.Firstly,the calibration plate is mapped to the perspective of the projector by encoding and decoding.Secondly,the grayscale image is restored and enhanced,and the external contour is extracted and the direction is judged according to the morphological characteristics of the calibration plate after adaptive threshold segmentation.Then the ellipse is identified by subpixel contour and the center coordinates are sorted.Finally,the center of the circle is corrected by the front view projection transformation.Experimental results show that the calibration process is simple,the calibration precision is high.The reprojection error of the projector is 0.065 pixels.