OpenCV 예제 - 웹캠 영상에 실시간 ROI 하기( Select ROI on Real Time webcam video)

 

 

웹캠 영상에 실시간으로 ROI 하는 예제입니다. 

 

 

 

 

#include <opencv2/opencv.hpp>
#include <iostream>

using namespace cv;
using namespace std;


bool mouse_is_pressing = false;
int start_x, start_y, end_x, end_y;
int step = 0;
Mat img_color;


void swap(int* v1, int* v2) {
	int temp = *v1;
	*v1 = *v2;
	*v2 = temp;
}


void mouse_callback(int event, int x, int y, int flags, void* userdata)
{
	Mat img_result = img_color.clone();


	if (event == EVENT_LBUTTONDOWN) {
		step = 1;

		mouse_is_pressing = true;
		start_x = x;
		start_y = y;



	}
	else if (event == EVENT_MOUSEMOVE) {

		if (mouse_is_pressing) {

			end_x = x;
			end_y = y;

			step = 2;
		}

	}
	else if (event == EVENT_LBUTTONUP) {

		mouse_is_pressing = false;

		end_x = x;
		end_y = y;
		
		step = 3;
	}
}



int main()
{

	//비디오 캡쳐 초기화
	VideoCapture cap(0);
	if (!cap.isOpened()) {
		cerr << "에러 - 카메라를 열 수 없습니다.\n";
		return -1;
	}
	
	namedWindow("Color", 1);
	setMouseCallback("Color", mouse_callback);


	while (1)
	{

		cap.read(img_color);
		if (img_color.empty()) {
			cerr << "빈 영상이 캡쳐되었습니다.\n";
			break;
		}

		switch (step)
		{

			case 1:
				circle(img_color, Point(start_x, start_y), 10, Scalar(0, 255, 0), -1);
				break;

			case 2:
				rectangle(img_color, Point(start_x, start_y), Point(end_x, end_y), Scalar(0, 255, 0), 3);
				break;

			case 3:

				if (start_x > end_x) {
					swap(&start_x, &end_x);
					swap(&start_y, &end_y);
				}


				Mat ROI(img_color, Rect(start_x, start_y, end_x - start_x, end_y - start_y));
				cvtColor(ROI, ROI, COLOR_BGR2GRAY);
				Canny(ROI, ROI, 150, 50);
				cvtColor(ROI, ROI, COLOR_GRAY2BGR);

				ROI.copyTo(img_color(Rect(start_x, start_y, end_x - start_x, end_y - start_y)));
				break;

		}


		imshow("Color", img_color);


		if (waitKey(25) >= 0)
			break;
	}


	destroyAllWindows();

	return 0;
}