Create cornerDetection.cpp

Author: niconielsen32

cornerDetection.cpp

@@ -0,0 +1,105 @@
+#include <opencv2/opencv.hpp>
+#include <iostream>
+
+using namespace cv;
+using namespace std;
+
+void harrisCornerDetector() {
+
+    Mat image, gray;
+    Mat output, output_norm, output_norm_scaled;
+
+    // Loading the actual image
+    //image = imread("C:/Users/kemik/OneDrive/Dokumenter/Downloads/squares.png", IMREAD_COLOR);
+    image = imread("C:/Users/kemik/OneDrive/Dokumenter/Downloads/house.jpg", IMREAD_COLOR);
+
+    // Edge cases
+    if (image.empty()) {
+        cout << "Error loading image" << endl;
+    }
+    cv::imshow("Original image", image);
+
+    // Converting the color image into grayscale
+    cvtColor(image, gray, cv::COLOR_BGR2GRAY);
+
+    // Detecting corners using the cornerHarris built in function
+    output = Mat::zeros(image.size(), CV_32FC1);
+    cornerHarris(gray, output,
+        3,              // Neighborhood size
+        3,              // Aperture parameter for the Sobel operator
+        0.04);          // Harris detector free parameter
+
+    // Normalizing - Convert corner values to integer so they can be drawn
+    normalize(output, output_norm, 0, 255, NORM_MINMAX, CV_32FC1, Mat());
+    convertScaleAbs(output_norm, output_norm_scaled);
+
+    // Drawing a circle around corners
+    for (int j = 0; j < output_norm.rows; j++) {
+        for (int i = 0; i < output_norm.cols; i++) {
+            if ((int)output_norm.at<float>(j, i) > 100) {
+                circle(image, Point(i, j), 4, Scalar(0, 0, 255), 2, 8, 0);
+            }
+        }
+    }
+
+    // Displaying the result
+    cv::resize(image, image, cv::Size(), 1.5, 1.5);
+    cv::imshow("Output Harris", image);
+    cv::waitKey();   
+}
+
+
+
+
+void shiTomasiCornerDetector() {
+
+    Mat image, gray;
+    Mat output, output_norm, output_norm_scaled;
+
+    // Loading the actual image
+    //image = imread("C:/Users/kemik/OneDrive/Dokumenter/Downloads/squares.png", IMREAD_COLOR);
+    image = imread("C:/Users/kemik/OneDrive/Dokumenter/Downloads/house.jpg", IMREAD_COLOR);
+
+    // Edge cases
+    if (image.empty()) {
+        cout << "Error loading image" << endl;
+    }
+    cv::imshow("Original image", image);
+
+    // Converting the color image into grayscale
+    cvtColor(image, gray, cv::COLOR_BGR2GRAY);
+
+
+    // Detecting corners using the goodFeaturesToTrack built in function
+    vector<Point2f> corners;
+    goodFeaturesToTrack(gray, 
+                        corners,
+                        100,            // Max corners to detect
+                        0.01,           // Minimal quality of corners
+                        10,             // Minimum Euclidean distance between the returned corners
+                        Mat(),          // Optional region of interest
+                        3,              // Size of an average block for computing a derivative covariation matrix over each pixel neighbothood
+                        false,          // Use Harri Detector or cornerMinEigenVal - Like when you create your own
+                        0.04);          // Free parameter for the Harris detector
+
+
+    // Drawing a circle around corners
+    for (size_t i = 0; i < corners.size(); i++){
+        circle(image, corners[i], 4, Scalar(0, 255, 0), 2, 8, 0);
+    }
+
+    // Displaying the result
+    cv::resize(image, image, cv::Size(), 1.5, 1.5);
+    cv::imshow("Output Shi-Tomasi", image);
+    cv::waitKey();
+}
+
+
+int main()
+{
+
+    harrisCornerDetector();
+    shiTomasiCornerDetector();
+
+    return 0;
+}