图片亮度鲜明度优化

#include<opencv2/opencv.hpp>
using namespace cv;
using namespace std;

int main(int argc, char** argv)
{
    // 读入图像，判断读入是否成功
    string fileName = samples::findFile("E://pythonProject1//image//img_1.png");
    Mat src = imread(fileName, IMREAD_COLOR);
    if (src.empty())
    {
        fprintf(stderr, "failed to load image: %s\n", fileName);
        system("pause");
        return EXIT_FAILURE;
    }

    Mat dst1, dst2, dst3;
    dst1 = Mat::zeros(src.size(), src.type());
    double alpha = 1.0;
    double beta = 0.0;
    double gama = 1.0;

    // 提示并输入 α  β  γ  的值
    cout << " Basic Linear Transforms " << endl;
    cout << "-------------------------" << endl;
    cout << "* Enter the alpha value [1.0-3.0]: "; cin >> alpha;
    cout << "* Enter the beta value [0-100]: ";    cin >> beta;
    cout << "* Enter the gama value [-1,1]: ";    cin >> gama;

    // 直接使用循环遍历每一个像素，应用公式
    double t1 = (double)getTickCount();
    for (int row = 0; row < src.rows; ++row)
        for (int col = 0; col < src.cols; ++col)
            for (int channel = 0; channel < src.channels(); ++channel)
            {
                dst1.at<Vec3b>(row, col)[channel] = saturate_cast<uchar>(alpha * src.at<Vec3b>(row, col)[channel] + beta);
            }
    double time1 = ((double)getTickCount() - t1) / getTickFrequency();
    cout << "Method by pixel use time:" << time1 << "(ms)" << endl;

    // 调用 convertTo() 函数调整对比度和亮度
    double t2 = (double)getTickCount();
    src.convertTo(dst2, -1, alpha, beta);
    double time2 = ((double)getTickCount() - t2) / getTickFrequency();
    cout << "Method by pixel use time:" << time2 << "(ms)" << endl;

    // 构建查找表
    Mat lookUpTable(1, 256, CV_8U);
    uchar* p = lookUpTable.ptr();
    for (int i = 0; i < 256; ++i)
        p[i] = saturate_cast<uchar>(pow(i / 255.0, gama) * 255.0);

    // 使用查找表进行对比度亮度调整
    double t3 = (double)getTickCount();
    LUT(src, lookUpTable, dst3);
    double time3 = ((double)getTickCount() - t3) / getTickFrequency();
    cout << "Method by γ correct use time:" << time3 << "(ms)" << endl;

    // 调整窗体大小，显示调整效果
    namedWindow("original", WINDOW_NORMAL);
    resizeWindow("original", Size(src.cols / 2, src.rows / 2));
    imshow("original", src);
    namedWindow("pixel set", WINDOW_NORMAL);
    resizeWindow("pixel set", Size(src.cols / 2, src.rows / 2));
    imshow("pixel set", dst1);
    namedWindow("convertTo", WINDOW_NORMAL);
    resizeWindow("convertTo", Size(src.cols / 2, src.rows / 2));
    imshow("convertTo", dst2);
    namedWindow("γ correct", WINDOW_NORMAL);
    resizeWindow("γ correct", Size(src.cols / 2, src.rows / 2));
    imshow("γ correct", dst3);
    waitKey(0);
    system("pause");
    return EXIT_SUCCESS;
}