【opencv】鱼眼图像畸变校正

http://blog.csdn.net/qq_15947787/article/details/50786782

http://blog.csdn.net/qq61394323/article/details/37812561

http://blog.csdn.net/qq_15947787/article/details/51441128

http://blog.csdn.net/qq_15947787/article/details/51471535

原图

球面透视投影（以空间左手坐标系，x轴为水平，y为竖直，z为光轴，投影面法线与xoz面夹角55度）

经过球面透视投影后，会存在两个灭点，此时，需要消去由于球面透视投影面存在角度引入的灭点。在这里采用opencv的仿射变换。

选取两条直线上的四个点，这两条直线相交与要消除的灭点。给出四个点校正后的位置。求变换矩阵。

透视变换

透视变换代码 opencv2.4.9+vs2012

 int main(int argc,char** argv)
 {
     CvPoint2D32f pts_src[4], pts_dst[4];
     CvMat *warp_matrix;
     IplImage *src, *dst;
     int offset_x, offset_y;

     src = cvLoadImage("correct_Img_1.jpg",1);
     dst = cvCreateImage( cvGetSize(src), src->depth, src->nChannels);

     //映射关系 (310,281)->(300,200)      (193,14)->(300,50)           (928,14)->(800,50)       (744,281)->(800,200)
     offset_x = 100;//为正，横向拉伸，为负，横向压缩
     offset_y = 0;//为正，纵向拉伸，为负，纵向压缩

     pts_src[0].x = 310;
     pts_src[0].y = 281;
     pts_src[1].x = 193;
     pts_src[1].y = 14;
     pts_src[2].x = 928;
     pts_src[2].y = 14;
     pts_src[3].x = 744;
     pts_src[3].y = 281;

     pts_dst[0].x = 300-offset_x;
     pts_dst[0].y = 200+offset_y;
     pts_dst[1].x = 300-offset_x;
     pts_dst[1].y = 50-offset_y;
     pts_dst[2].x = 800+offset_x;
     pts_dst[2].y = 50-offset_y;
     pts_dst[3].x = 800+offset_x;
     pts_dst[3].y = 200+offset_y;

     warp_matrix = cvCreateMat(3,3,CV_32FC1);

     //计算变换矩阵
     cvGetPerspectiveTransform( pts_src, pts_dst ,warp_matrix);
     //透视变换
     cvWarpPerspective( src, dst ,warp_matrix);

     cvNamedWindow("dst",1);
     cvShowImage("dst",dst);
     cvSaveImage("out.jpg",dst);

     cvWaitKey(0);

     cvReleaseImage(&dst);
     cvDestroyWindow("dst");

     return 0;
 }