svm과 머신러닝

ch15/knnplane/main.cpp

@@ -0,0 +1,98 @@
+#include "opencv2/opencv.hpp"
+#include <iostream>
+
+using namespace cv;
+using namespace cv::ml;
+using namespace std;
+
+Mat img;
+Mat train, label;
+Ptr<KNearest> knn;
+int k_value = 1;
+
+void on_k_changed(int k, void* userdata);
+void addPoint(const Point& pt, int cls);
+void trainAndDisplay();
+
+int main() {
+	img = Mat::zeros(Size(500, 500), CV_8UC3);
+	knn = KNearest::create();
+
+	const int NUM = 30;
+	Mat rn(NUM, 2, CV_32SC1);
+
+	randn(rn, 0, 50);
+	for (int i = 0; i < NUM; i++) {
+		addPoint(Point(rn.at<int>(i, 0) + 150, rn.at<int>(i, 1) + 150), 0);
+	}
+	randn(rn, 0, 50);
+	for (int i = 0; i < NUM; i++) {
+		addPoint(Point(rn.at<int>(i, 0) + 350, rn.at<int>(i, 1) + 150), 1);
+	}
+	randn(rn, 0, 70);
+	for (int i = 0; i < NUM; i++) {
+		addPoint(Point(rn.at<int>(i, 0) + 250, rn.at<int>(i, 1) + 400), 2);
+	}
+
+	namedWindow("knn");
+	createTrackbar("k", "knn", &k_value, 10, on_k_changed);
+
+	trainAndDisplay();
+
+	waitKey();
+	destroyAllWindows();
+	return 0;
+}
+
+void on_k_changed(int k, void* userdata) {
+	if (k_value < 1) {
+		k_value = 1;
+	} else {
+		k_value = k;
+	}
+	trainAndDisplay();
+}
+
+void addPoint(const Point& pt, int cls) {
+	Mat new_sample = (Mat_<float>(1, 2) << pt.x, pt.y);
+	train.push_back(new_sample);
+
+	Mat new_label = (Mat_<int>(1, 1) << cls);
+	label.push_back(new_label);
+}
+
+void trainAndDisplay() {
+	knn->train(train, ROW_SAMPLE, label);
+
+	for (int i = 0; i < img.rows; i++) {
+		for (int j = 0; j < img.cols; j++) {
+			Mat sample = (Mat_<float>(1, 2) << j, i);
+
+			Mat res;
+			knn->findNearest(sample, k_value, res);
+
+			int response = cvRound(res.at<float>(0, 0));
+			if (response == 0)
+				img.at<Vec3b>(i, j) = Vec3b(128, 128, 255);
+			if (response == 1)
+				img.at<Vec3b>(i, j) = Vec3b(128, 255, 128);
+			if (response == 2)
+				img.at<Vec3b>(i, j) = Vec3b(255, 128, 128);
+		}
+	}
+
+	for (int i = 0; i < train.rows; i++) {
+		int x = cvRound(train.at<float>(i, 0));
+		int y = cvRound(train.at<float>(i, 1));
+		int l = label.at<int>(i, 0);
+
+		if (l == 0)
+			circle(img, Point(x, y), 5, Scalar(0, 0, 128), -1, LINE_AA);
+		if (l == 1)
+			circle(img, Point(x, y), 5, Scalar(0, 128, 0), -1, LINE_AA);
+		if (l == 2)
+			circle(img, Point(x, y), 5, Scalar(128, 0, 0), -1, LINE_AA);
+	}
+
+	imshow("knn", img);
+}