基于双经度模型的鱼眼图像畸变矫正方法

针对鱼眼镜头拍摄图片桶形畸变大的问题,提出了一种基于双经度图像畸变矫正算法,以改善其视觉效果。首先,在未知镜头视角大小且鱼眼图像非圆形的情况下,利用鱼眼图像特征求得球面中心及其半径,并对半径大小做优化处理以减弱极点畸变;在此基础上采用双经度模型方法,通过正交投影策略将鱼眼图像映射到球面上,转化为球面横向经度和纵向经度坐标,从而投射为以横向、纵向双经度坐标为基础的正方形平面图像,实现图像的快速、精确变换。最后,利用2个实例验证了该文所提算法的有效性和可行性。

Double longitude model based correction method for fish eye image distortion

Aiming at the problem of large barrel distortion of fish eye lens that has wide field of view, a novel image distortion correction algorithm based on double longitude spherical model is proposed to improve the visual effect. First of all, under the condition that the camera lens angle is unknown and the fisheye image is non circular, the center and radius of the spherical model is obtained using the fisheye image features, and then the radius is optimized to weaken the pole distortion. Based on above, adopting the double longitude model algorithm, the fish eye image is mapped to the sphere with orthogonal projection strategy, and then is transformed into spherically horizontal and vertical longitude coordinates, thereby projected to the horizontal and vertical longitude coordinate based square plan image; and the fast and accurate image conversion is achieved. At last, the results of two experiment examples verify the effectiveness and feasibility of the proposed method.