图像对比度、亮度值调整

#include<opencv2/opencv.hpp>
#include<iostream>

using namespace std;
using namespace cv;

static void on_ContrastAndBright(int, void *);
static void ShowHelpText();

int g_nContrastValue;   //对比度值
int g_nBrightValue;    //亮度值
Mat g_srcImage, g_dstImage;

int main() {
    //读取输入图像
    g_srcImage = imread("C:\Users\Nelsoner\Desktop\Camera Roll\05.jpg");
    g_dstImage = Mat::zeros(g_srcImage.size(), g_srcImage.type());

    //设定对比度和亮的初值
    g_nContrastValue = 80;
    g_nBrightValue = 80;



    //窗口
    namedWindow("【效果图】", 1);

    //创建滑块
    createTrackbar("对比度：", "【效果图】", &g_nContrastValue, 300, on_ContrastAndBright);
    createTrackbar("亮  度：", "【效果图】", &g_nBrightValue, 200, on_ContrastAndBright);

    //进行回调函数的初始化
    on_ContrastAndBright(g_nContrastValue, 0);
    on_ContrastAndBright(g_nBrightValue, 0);

    waitKey();
    return  0;
}

static void on_ContrastAndBright(int, void *) {
    //创建窗口
    namedWindow("【原始图窗口】", 1);
    //三个for循环，执行运算g_dstImage(i,j) = a*g_srcImage(i,j) +b
    for (int y = 0; y < g_srcImage.rows; y++) {
        for (int x = 0; x < g_srcImage.cols; x++) {
            for (int c = 0; c < 3; c++) {
                g_dstImage.at<Vec3b>(y, x)[c] = saturate_cast<uchar>((g_nContrastValue*0.01)*(g_srcImage.at<Vec3b>(y, x)[c]) + g_nBrightValue);
            }
        }
    }

    //显示图像
    imshow("【原始图窗口】", g_srcImage);
    imshow("【效果图】", g_dstImage);
}