Opencv实现对象提取与测量

时间：2021-06-28 08:24:39|栏目：C代码|点击：次

本文实例为大家分享了Opencv3实现对象提取与测量的具体代码，供大家参考，具体内容如下

案例背景：下图为一张卫星拍摄的图片，要获取其中岛屿的周长和面积

方案思路：高斯模糊去噪，灰度二值化提取轮廓，闭操作填充缝隙或小的孔洞，寻找轮廓，通过轮廓特征选择轮廓

#include<opencv2\opencv.hpp>
using namespace cv;
using namespace std;
int main(int arc, char** argv) { 
 Mat src = imread("1.jpg");
 namedWindow("input", CV_WINDOW_AUTOSIZE);
 imshow("input", src);
 //该高斯模糊去噪
 GaussianBlur(src, src, Size(15, 15), 0, 0);
 imshow("output1", src);
 //灰度二值化
 Mat gray,binary;
 cvtColor(src, gray, CV_BGR2GRAY);
 threshold(gray, binary, 0, 255, THRESH_BINARY | THRESH_TRIANGLE);
 imshow("output2", binary);
 //闭操作
 Mat kernel = getStructuringElement(MORPH_RECT, Size(4, 4));
 morphologyEx(binary, binary, MORPH_CLOSE, kernel);
 imshow("output3", binary);
 //寻找轮廓
 vector<vector<Point>>contours;
 Mat draw = Mat::zeros(src.size(), CV_8UC3);
 findContours(binary, contours, RETR_EXTERNAL, CHAIN_APPROX_SIMPLE);
 for (int i = 0; i < contours.size(); i++) {
 Rect rect = boundingRect(contours[i]);
 if (rect.width < src.cols / 2 || rect.height>src.rows-20)continue;//筛选轮廓
 drawContours(draw, contours, i, Scalar(0, 0, 255), 1);
 printf("area:%f\n", contourArea(contours[i]));
 printf("length:%f\n",arcLength(contours[i],true));
 }
 imshow("output4", draw);
 waitKey(0);
 return 0;
}