logPolar
头文件:opencv2/imgproc/imgproc.hpp
作用: 对图形进行极坐标变换
函数原型:
void cvLogPolar(const CvArr src, CvArr dst, CvPoint2D32f center,double M,int flags)
- 参数1 src:输入图像
- 参数2 dst:输出图形
- 参数3 center:设置坐标原点位置
- 参数4 M:尺度参数$\rho=M\times log(r)$
- 参数5 flags:标志位和插值方法
CV_INTER_LINEAR 内部采用线性插值,注意由于M的存在结果可能不会相邻整数,中间需要差值,逆变换也需要插值
CV_WARP_FILL_OUTLIERS 对于超出图像边界区域如何处理
示例:
#include<bits/stdc++.h>
#include<opencv2/highgui/highgui.hpp>
#include<opencv2/imgproc/imgproc.hpp>
using namespace std;
char file[] = "C:\\Users\\Administrator\\Desktop\\test.avi";
char filew[] = "C:\\Users\\Administrator\\Desktop\\test1.avi";
char file1[] = "C:\\Users\\Administrator\\Desktop\\2-1.jpg";
int main() {
cv::namedWindow("1", cv::WINDOW_AUTOSIZE);
cv::namedWindow("2", cv::WINDOW_AUTOSIZE);
cv::VideoCapture cap(file);
double fps = cap.get(cv::CAP_PROP_FPS);
cv::Size size((int)cap.get(cv::CAP_PROP_FRAME_WIDTH), (int)cap.get(cv::CAP_PROP_FRAME_HEIGHT));
cv::VideoWriter writer; //输出流
//流文件,编码,帧率,大小
writer.open(filew, CV_FOURCC('M', 'J', 'P', 'G'), fps, size);
cv::Mat logpolar_frame, bgr_frame;
for (;;) {
cap >> bgr_frame;
if (bgr_frame.empty())break;
cv::imshow("1", bgr_frame);
cv::logPolar(bgr_frame, logpolar_frame, cv::Point2f(bgr_frame.cols / 2, bgr_frame.rows / 2),100, cv::WARP_FILL_OUTLIERS);
cv::imshow("2", logpolar_frame);
writer << logpolar_frame;
if (cv::waitKey(10) > 0)break;
}
cv::waitKey(0);
}