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【opencv学习】鼠标回调函数、鼠标控制画矩形

news 2025/6/28 1:53:19

#include <iostream>
#include <opencv2/opencv.hpp>
using namespace cv;
#define WinDow "程序窗口"void MouseHandle(int event, int x, int y, int flags, void* param);//鼠标回调函数
void Drawrectangle(cv::Mat& img, cv::Rect box);//矩形绘制函数
bool DrawingBox = false;//是否就行矩形绘制
Rect y_rectangle;//绘制的图形参数（位置，大小）
RNG rng(12345);//random number generator随机数生成器int main()
{y_rectangle = Rect(-1, -1, 0, 0);//初始化参数Mat srcimage(600, 800, CV_8UC3), tempimage;//初始化对象600*800,3通道srcimage = Scalar::all(255);//初始化srcimage背景颜色namedWindow(WinDow);setMouseCallback(WinDow, MouseHandle, (void*)&srcimage);//鼠标操作回调函数,边显示，边画图while (1){srcimage.copyTo(tempimage);//将srcimage复制到tempimageif (DrawingBox)Drawrectangle(tempimage, y_rectangle);imshow(WinDow, tempimage);if (waitKey(10) == 27)//按esc跳出break;}return 0;
}void MouseHandle(int event, int x, int y, int flags, void* param)
{Mat& image = *(cv::Mat*)param;switch (event){case EVENT_MOUSEMOVE://鼠标移动{if (DrawingBox)//绘制矩形，则记录下矩形的长宽{y_rectangle.width = x - y_rectangle.x;//要绘制的矩形宽度为：当前坐标值减去移动前的坐标值y_rectangle.height = y - y_rectangle.y;}}break;case EVENT_LBUTTONDOWN://点击鼠标左键{DrawingBox = true;//绘制开关打开y_rectangle = Rect(x, y, 0, 0);//记录矩形左上角起始点}break;case EVENT_LBUTTONUP://鼠标左键抬起{DrawingBox = false;//绘制开关关闭//如果鼠标往左上两个方向移动，那么有一个值为负数if (y_rectangle.width < 0){y_rectangle.x += y_rectangle.width;//坐标值y_rectangle.width *= -1;//宽度值}if (y_rectangle.height < 0){y_rectangle.y += y_rectangle.height;y_rectangle.height *= -1;}Drawrectangle(image, y_rectangle);//动作完成以后要绘制出图形}break;}
}void Drawrectangle(cv::Mat& img, cv::Rect box)
{rectangle(img, box.tl(), box.br(), Scalar(rng.uniform(0, 255), rng.uniform(0, 255), rng.uniform(0, 255)));
}