给出10个opencv c++示例代码

1. 读取并显示图像:

#include <opencv2/opencv.hpp>
using namespace cv;
int main()
{
    Mat img = imread("image.jpg");
    imshow("image", img);
    waitKey(0);
    return 0;
}

2. 灰度图像转换:

#include <opencv2/opencv.hpp>
using namespace cv;
int main()
{
    Mat img = imread("image.jpg");
    Mat gray;
    cvtColor(img, gray, COLOR_BGR2GRAY);
    imshow("gray image", gray);
    waitKey(0);
    return 0;
}

3. 图像裁剪:

#include <opencv2/opencv.hpp>
using namespace cv;
int main()
{
    Mat img = imread("image.jpg");
    Rect roi(100, 100, 200, 200);
    Mat crop = img(roi);
    imshow("cropped image", crop);
    waitKey(0);
    return 0;
}

4. 图像缩放:

#include <opencv2/opencv.hpp>
using namespace cv;
int main()
{
    Mat img = imread("image.jpg");
    Mat resize;
    cv::resize(img, resize, cv::Size(), 0.5, 0.5);
    imshow("resized image", resize);
    waitKey(0);
    return 0;
}

5. 图像旋转:

#include <opencv2/opencv.hpp>
using namespace cv;
int main()
{
    Mat img = imread("image.jpg");
    Mat rotate;
    Point2f center(img.cols/2, img.rows/2);
    Mat rot_mat = getRotationMatrix2D(center, 45, 1.0);
    warpAffine(img, rotate, rot_mat, img.size());
    imshow("rotated image", rotate);
    waitKey(0);
    return 0;
}

6. 图像阈值化:

#include <opencv2/opencv.hpp>
using namespace cv;
int main()
{
    Mat img = imread("image.jpg", 0);
    Mat threshold;
    threshold(img, threshold, 128, 255, THRESH_BINARY);
    imshow("threshold image", threshold);
    waitKey(0);
    return 0;
}

7. 图像边缘检测:

#include <opencv2/opencv.hpp>
using namespace cv;
int main()
{
    Mat img = imread("image.jpg", 0);
    Mat edges;
    Canny(img,