Binary

typedef struct
{
    int index;//下标
    int freq;//频数
}Peak;
void Binary()
{
    char imageName[] = "C:\\Users\\24932\\Desktop\\landsat8\\123.png";
    Mat M = imread(imageName, IMREAD_COLOR);   // 读入图片 
    if (M.empty())     // 判断文件是否正常打开  
    {
        cout << "open file error";
    }
    imshow("原始图像", M);
    int channel = M.channels();
    int rows = M.rows;
    int cols = M.cols;
    Mat impGray(rows, cols, CV_8UC1);
    if (channel == 3)
    {
        impGray = ToGrey(M).clone();
        imshow("灰度图像", impGray);
    }
    if (channel == 1)
    {
        impGray = M.clone();
    }
    imshow("灰度图像", impGray);
    Peak peaks[256];//波峰
    int histogram[256];//直方图
    for (int i = 0; i < 255; i++) histogram[i] = 0;//初始直方图各个灰度值个数为0;
    for (int i = 0; i < rows; i++)
    {
        for (int j = 0; j < cols; j++)
        {
            histogram[impGray.at<uchar>(i, j)]++;//统计各个灰度出现的次数得到直方图
        }
    }
    int size = 0;//波峰数
    for (int i = 1; i < 254; i++)//统计波峰数量与频数
    {
        if (histogram[i] > histogram[i - 1] && histogram[i] > histogram[i + 1])
        {
            peaks[size].index = i;
            peaks[size].freq = histogram[i];
            size++;
        }
    }
    //寻找最大的两个波峰
    Peak Max = peaks[0], Snd = peaks[0];
    for (int i = 0; i <size; i++)
    {
        if (peaks[i].freq > Max.freq)
        {
            Snd = Max;
            Max = peaks[i];
        }
        else if (peaks[i].freq>Snd.freq)
        {
            Snd = peaks[i];
        }
    }
    //找到波谷;
    int q = min(Max.index, Snd.index);//双峰值较小下标
    int p = max(Max.index, Snd.index);//双峰值较大下标
    Peak k = Max;//波谷点
    for (;q  < p; q++)
    {
        if (histogram[q]<k.freq)
        {
            k.freq = histogram[q];
            k.index = q;
        }
    }
    //二值化
    Mat Mq(rows, cols, CV_8UC1);
    for (int i = 0; i < rows; i++)
    {
        for (int j = 0; j < cols; j++)
        {
            if (impGray.at<uchar>(i, j) < k.index)
                Mq.at<uchar>(i, j) =0;
            else
                Mq.at<uchar>(i, j) =255;
        }
    }
    imshow("二值化后图像", Mq);
    imwrite("C:\\Users\\24932\\Desktop\\landsat8\\峰值法二值化.png", Mq);
    waitKey();

}