利用該方法對圖形進行二值化處理，能夠很好的除去光線對圖片的影響

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

void thresholdIntegral2(Mat inputMat, Mat outputMat)
{
    int nRows = inputMat.rows;
    int nCols = inputMat.cols;
    // create the integral image
    Mat sumMat;
    integral(inputMat, sumMat);
    int
 
 S = MAX(nRows, nCols) / 8;
    double T = 0.15;
    // perform thresholding
    int s2 = S / 2;
    int x1, y1, x2, y2, count, sum;
    int* p_y1, *p_y2;
    uchar* p_inputMat, *p_outputMat;
    for (int i = 0; i < nRows; ++i)
    {
        y1 = i - s2;
        y2 = i + s2;
        if (y1 < 0)
        {
            y1 = 0
 
;
        }
        if (y2 >= nRows)
        {
            y2 = nRows - 1;
        }
        p_y1 = sumMat.ptr<int>(y1);
        p_y2 = sumMat.ptr<int>(y2);
        p_inputMat = inputMat.ptr<uchar>(i);
        p_outputMat = outputMat.ptr<uchar>(i);
        for (int j = 0; j < nCols; ++j)
        {
            // set the SxS region
 

            x1 = j - s2;
            x2 = j + s2;
            if (x1 < 0)
            {
                x1 = 0;
            }
            if (x2 >= nCols)
            {
                x2 = nCols - 1;
            }
            count = (x2 - x1)* (y2 - y1);
            sum = p_y2[x2] - p_y1[x2] - p_y2[x1] + p_y1[x1];
            if ((int)(p_inputMat[j] * count) < (int)(sum* (1.0 - T)))
            {
                p_outputMat[j] = 0;
            }
            else
            {
                p_outputMat[j] = 255; 
            }
        }
    }
}

int main()
{
    Mat src = imread("img2.jpg");
    Mat grad;
    cvtColor(src, grad, CV_BGR2GRAY);
    //Mat bw2 = Mat::zeros(grad.size(), CV_8UC1);
    thresholdIntegral2(grad, grad);
    imshow("【二值化圖】", grad);
    imwrite("img2Grad.jpg", grad);
    waitKey(0); 
    return 0;
}

結果如下圖所示：

一般方法進行二值化處理

#include<iostream>
#include<opencv2\opencv.hpp>
using namespace std;
using namespace cv;
int main()
{
    IplImage *MBDst = cvLoadImage("img2.jpg");
    IplImage* MBSrc = cvCreateImage(cvGetSize(MBDst), MBDst->depth, MBDst->nChannels);
    cvCopy(MBDst, MBSrc);
    cvShowImage("原圖", MBSrc);
    cvThreshold(MBSrc, MBSrc, 120, 255, CV_THRESH_BINARY);
    cvShowImage("【二值化圖】", MBSrc);
    cvWaitKey(0);
    return 0;
}

結果如下圖所示：