鱼眼镜头径向畸变的校正方法

针对鱼眼图像存在的径向畸变,提出了一种通过计算鱼眼镜头径向畸变函数来校正鱼眼图像的方法。首先,根据鱼眼镜头本身的特性运用Hough变换获取鱼眼图像的圆心以及校正半径;运用所提出的圆柱形棋盘格模版来完成径向畸变的标定,通过多项式拟合出鱼眼图像直径上采样点到圆心的距离和实际该采样点像点对应的物点所在视角之间的关系,从而将鱼眼图像恢复到球形投影面上;最后运用平面投影模型矫正出符合人类视觉感官的平面透视图像,并用一个圆柱形的投影面校正出了360°全景图。最后的实验结果证明了此方法的有效性。

Correction method for radial distortion of fisheye lens

Aiming at the radial distortion in fisheye image, a method to correct the fisheye image by computing the radial distortion function is proposed in this study. First, the coordination of the image center and radius utilized for correction is obtained through Hough Transform according to characteristics of fisheye lens. The radial distortion calibration is accomplished by using the cylindrical checkerboard template which is proposed in this paper. The relation between the distance from the sampling points on radial direction of the image to the image center and the viewing angle of object points of the sampling points is achieved by fitting a polynomial. Then, the fisheye image is recovered to the spherical projective plane. Finally, the planar perspective image which is accord with human version is realized by using a planar projective model. A corrected 360° panorama is obtained by a cylindrical projective plane. The experimental results show that the proposed method is effective for correcting the radial distortion.