短视频直播源码，CreateTrackbar亮度和对比度调整

短视频直播源码，CreateTrackbar亮度和对比度调整实现的相关代码

int cv::createTrackbar(

const cv::String& trackbarname, 轨迹条名字,

const cv::String&winname, 窗口名字,

int* value,  滑块初始位置,

int count ,滑块达到最大位置的值,

cv::TrackbarCallback onChange = (cv::creatTrackbarCallback)0,默认值为0,指向回调函数

 void* userdata =(void*) 0  默认值为0，用户传给回调函数的数据值

);           


#include<opencv2/opencv.hpp>
#include<iostream>
using namespace cv;
using namespace std;
 
 
static void on_light(int b, void* usedata) {
    Mat image = *((Mat*)usedata);
    Mat out = Mat::zeros(image.size(), image.type());
    Mat m = Mat::zeros(image.size(), image.type());
    m = Scalar(b, b, b);
    add(image, m, out);
    imshow("亮度和对比度调整", out);
}
 
static void on_contrast(int b, void* usedata) {
    Mat image = *((Mat*)usedata);
    Mat out = Mat::zeros(image.size(), image.type());
    Mat m = Mat::zeros(image.size(), image.type());
    m = Scalar(b, b, b);
    double alpha = b / 100.0;
    addWeighted(image, alpha, m, 0.0, 0.0, out);
    imshow("亮度和对比度调整", out);
}
 
int main(int argc, char** argv) {
    Mat image = imread("C:/Users/YY/Pictures/Saved Pictures/1.jpg");
    int light = 50;
    int contrast = 100;
    namedWindow("亮度和对比度调整", WINDOW_AUTOSIZE);
    createTrackbar("Value", "亮度和对比度调整", &light, 100, on_light,(void*)(&image));
    createTrackbar("Contrast", "亮度和对比度调整", &contrast, 200, on_contrast, (void*)(&image));
    on_light(50, &image);
    waitKey(0);
    destroyAllWindows();
    return 0;
}