opencv鼠标操作与响应

//鼠标事件
Point sp(-1, -1);
Point ep(-1, -1);
Mat temp;
static void on_draw(int event, int x, int y, int flags, void *userdata) {Mat image = *((Mat*)userdata);if (event == EVENT_LBUTTONDOWN) {sp.x = x;sp.y = y;std::cout << "start point:"<<sp << std::endl;}else if (event == EVENT_LBUTTONUP) {ep.x = x;ep.y = y;std::cout << "end point:" << ep << std::endl;int dx = ep.x - sp.x;int dy = ep.y - sp.y;if (dx > 0 && dy > 0) {Rect box(sp.x, sp.y, dx, dy);imshow("ROI", image(box));rectangle(image, box, Scalar(0, 0, 255), 2, 8, 0);imshow("鼠标绘制", image);//为下次绘制做准备sp.x = -1;sp.y = -1;}}else if (event == EVENT_MOUSEMOVE) {if (sp.x > 0 && sp.y > 0) {ep.x = x;ep.y = y;std::cout << "end point:" << ep << std::endl;int dx = ep.x - sp.x;int dy = ep.y - sp.y;if (dx > 0 && dy > 0) {Rect box(sp.x, sp.y, dx, dy);temp.copyTo(image);rectangle(image, box, Scalar(0, 0, 255), 2, 8, 0);imshow("鼠标绘制", image);}}}
}void QuickDemo::mouse_drawing_demo(Mat &image) {namedWindow("鼠标绘制", WINDOW_AUTOSIZE);setMouseCallback("鼠标绘制", on_draw, (void*)(&image));imshow("鼠标绘制", image);temp = image.clone();
}