#include<iostream>
#include<opencv2/highgui.hpp>
#include<opencv2/core.hpp>
#include<opencv2/imgproc.hpp>
using namespace std;
using namespace cv;
int definePos=50;
char str[]="Hello";
void onTrackbar_src(int pos, void *userdata)
{
imshow("src",*(Mat *)userdata*pos/100.0);//使用userdata，先强制转换格式，然后此函数要求传入内容，所以还要取内容符，第三步
}
int main()
{
Mat src=imread("/home/shensy/图片/fangzi1.jpg",IMREAD_ANYCOLOR);
if(!src.data)
return -1;
Mat *psrc=&src;//指针指向图片，第一步
namedWindow("src");
createTrackbar("亮度","src",&definePos,100,onTrackbar_src,psrc);//将图片指针传入userdata，第二步
putText(src,str,Point(100,100),FONT_HERSHEY_SIMPLEX,4,Scalar(0,0,255),3);
imshow("src",src*getTrackbarPos("亮度","src")/100.0);
waitKey(0);
return 0;
}
