第三天：鼠标与滑动条相关操作

来源：互联网发布：js监听函数是否执行编辑：程序博客网时间：2024/06/05 14:54

（1）、鼠标操作

指定鼠标操作消息回调函数，setMouseCallback(),原型如下：

wCV_EXPORTS void setMouseCallback(coonst string& winname,MouseCallback onMouse,void* userdate = 0);inname----窗口名;onMouse----触发鼠标事件被调用的函数指针;函数原型：void Fun(int event,int x,int y,int flags,void * param);event取值：enum{    CV_EVENT_MOUSEMOVE = 0,    CV_EVENT_LBUTTONDOWN = 1,    CV_EVENT_RBUTTONDOWN = 2,    CV_EVENT_MBUTTONDOWN = 3,    CV_EVENT_LBUTTONUP = 4,    CV_EVENT_RBUTTONUP = 5,    CV_EVENT_MBUTTONUP = 6,    CV_EVENT_LBUTTONDBLCLK = 7,    CV_EVENT_RBUTTONDBLCLK = 8,    CV_EVENT_MBUTTONDBLCLK = 9,}userdata-----用户定义传到回调函数的参数，默认值为0;

（2）、滑动条操作
创建滑动条并指定回调函数，createTrackbar()原型如下:

CV_EXPORTS int creatTrackbar(const string& trackbarname,const string& winname,int* value,int count,TrackbarCallback onChang=0,void* userdate=0);trackbarname-----滚动条名称winname-----滚动条所依附的窗口名称(namedWindow创建)value----指向型指针，表示滑动块位置count---滑动块最大位置，默认最小为0onChange----指向回调函数的指针，原型必须为void xxx(int, void*);userdata -----用户传给回调函数的数据，默认值0获取滑动条当前位置：CV_EXPORTS_W int getTrackbarPos(const string& trackbarname,const string& winname);

（3）、例子

#include "opencv2/opencv.hpp"#include <iostream>using namespace cv;using namespace std;//Point pt;////void OnMouse(int event, int x, int y, int flags, void* param)//{//Mat img = *(Mat*)param;//switch(event)//{//case CV_EVENT_LBUTTONDOWN://pt.x = x;//pt.y = y;//break;//case CV_EVENT_LBUTTONUP://rectangle(img, pt, Point(x, y), Scalar(0, 255, 0), 2, 8);//break;//default://break;//}///*if(event == CV_EVENT_LBUTTONDOWN)//{//cout<<"Mouse down"<<endl;//circle(img, Point(x, y), 80, Scalar(255, 255, 0), 2, 8);//}*/////}Mat dstImg;int value = 20;void OnChange(int, void* param){Mat srcImg = *(Mat*) param;//threshold(srcImg, dstImg, value, 255, THRESH_BINARY);Canny(srcImg, dstImg, value, 255);imshow("TrackBar", dstImg);}void main(){//Mat img(500, 500, CV_8UC3, Scalar(255, 255, 255));//namedWindow("Mouse", CV_WINDOW_AUTOSIZE);//setMouseCallback("Mouse", OnMouse, &img);//while(1)//{//imshow("Mouse", img);//if(27==waitKey(10))  //按下Esc跳出//break;//}Mat srcImg = imread("1.jpg", 0);namedWindow("TrackBar", CV_WINDOW_AUTOSIZE);createTrackbar("Threshold", "TrackBar", &value, 255, OnChange, &srcImg);//threshold(srcImg, dstImg, value, 255, THRESH_BINARY);Canny(srcImg, dstImg, value, 255);imshow("TrackBar", dstImg);waitKey(0);}

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