opencv C++极坐标变换

#include<opencv2/core/core.hpp> #include<opencv2/highgui/highgui.hpp> #include<opencv2/imgproc/imgproc.hpp> #include<iostream>  // center:极坐标的变换中心 // minr:变换中心的最小距离 // mintheta:最小距离 // thetaStep:角度的变换步长 // rStep:距离的变换步长 cv::Mat polar(cv::Mat I,cv::Point2f center,cv::Size size,float minr=0,float mintheta=0,float thetaStep=1.0/4,float rStep=1.0){     cv::Mat ri=cv::Mat::zeros(cv::Size(1,size.height),CV_32FC1);     for(int i=0;i<size.height;++i)         ri.at<float>(i,0)=minr+i*rStep;     cv::Mat r=cv::repeat(ri,1,size.width);     cv::Mat thetaj=cv::Mat::zeros(cv::Size(size.width,1),CV_32FC1);     for(int i=0;i<size.width;++i)         thetaj.at<float>(0,i)=mintheta+i*thetaStep;     cv::Mat theta=cv::repeat(thetaj,size.height,1);     cv::Mat x,y;     cv::polarToCart(r,theta,x,y,true);     x+=center.x;     y+=center.y;     cv::Mat dst =125*cv::Mat::ones(size,CV_8UC1);     for(int i=0;i<size.height;++i){         for(int j=0;j<size.width;++j){             float xij=x.at<float>(i,j);             float yij=y.at<float>(i,j);             int nearestx=int(round(xij));             int nearesty=int(round(yij));             if((0<=nearestx&&nearestx<I.cols)&&(0<=nearesty&&nearesty<I.rows))                 dst.at<uchar>(i,j)=I.at<uchar>(nearesty,nearestx);         }     }     return dst; }   int main(){     cv::Mat I=cv::imread("/home/nan/ͼƬ/openimage/circleWithText.jpg",cv::IMREAD_GRAYSCALE);     if(!I.data) return -1;     float thetaStep=1.0/4;  // thetaStep=0.25代表整个圆环，thetaStep=0.5代表半个圆环，thetaStep=1代表1/4个圆环。     float minr=55;     cv::Size size (int(360/thetaStep),50);  //50:圆环文字的大致高度。     // 圆环角度范围为(0,360),输出圆环图像的宽度为(360/thetaStep):     cv::Mat dst=polar(I,cv::Point2f(110,109),size,minr);     //cv::imshow("极坐标变换0:",dst);     cv::flip(dst,dst,0);  // 0 meansflipping around the x-axis and positive value (for example, 1) means     // flipping around y-axis. Negative value (for example, -1) means flipping around both axes.     cv::imshow("I",I);     cv::imshow("最近邻插值极坐标变换:",dst);      cv::linearPolar(I,dst,cv::Point2f(110,109),100,cv::INTER_LINEAR);     cv::imshow("线性插值极坐标变换:",dst);      cv::logPolar(I,dst,cv::Point2f(110,109),40,cv::WARP_FILL_OUTLIERS);     cv::imshow("对数极坐标变换:",dst);     //cv::InterpolationFlags     cv::waitKey(0);     return 0; }

来源：博客园

作者：hiligei

链接：https://www.cnblogs.com/ligei/p/11529031.html