double calPSNR(VideoCapture capture2, VideoCapture capture3) { Mat frame1, frame2; double mse = 0; int frameCount = 0;//初始化 while (1) { // 从两个视频中读取一帧 capture2 >> frame1; capture3 >> frame2; if (frame1.empty() || frame2.empty()) { break; } // 计算两帧之间的MSE Mat diff; absdiff(frame1, frame2, diff); diff = diff.mul(diff); Scalar mseScalar = mean(diff); double frameMse = mseScalar.val[0] + mseScalar.val[1] + mseScalar.val[2]; // 累计MSE mse += frameMse; frameCount++; } // 计算平均MSE mse /= frameCount; cout << "MSE: " << mse << endl; //计算峰值信噪比PSNR double psnr = 0;//初始化 psnr = 10 * log10((255 * 255) / mse); return psnr; }又错误吗

在计算PSNR时，可能会出现除以0的情况，需要在代码中添加判断。另外，计算PSNR值时需要注意，MSE值越小，PSNR值越大。建议将代码中计算平均MSE的语句放到计算PSNR之前。以下是修改后的代码：

double calPSNR(VideoCapture capture2, VideoCapture capture3) {
    Mat frame1, frame2;
    double mse = 0;
    int frameCount = 0;//初始化

    while (1) {
        // 从两个视频中读取一帧
        capture2 >> frame1;
        capture3 >> frame2;

        if (frame1.empty() || frame2.empty()) {
            break;
        }

        // 计算两帧之间的MSE
        Mat diff;
        absdiff(frame1, frame2, diff);
        diff = diff.mul(diff);
        Scalar mseScalar = mean(diff);
        double frameMse = mseScalar.val[0] + mseScalar.val[1] + mseScalar.val[2];

        // 累计MSE
        mse += frameMse;
        frameCount++;
    }

    if (mse == 0) {
        return 100; // 避免除以0
    }

    // 计算平均MSE
    mse /= frameCount;
    cout << "MSE: " << mse << endl;

    // 计算峰值信噪比PSNR
    double psnr = 0;//初始化
    psnr = 10 * log10((255 * 255) / mse);

    return psnr;
}