opencv画面抖动检测

//static cv::Mat lastMat = Mat();
//static int similarityCount = 0;

int getSimilarity(const Mat &matROI_IDCard, const Mat &lastMat) {
    Mat matDst1, matDst2;

    resize(matROI_IDCard, matDst1, Size(8, 8), 0, 0, INTER_CUBIC);
    resize(lastMat, matDst2, Size(8, 8), 0, 0, INTER_CUBIC);
    cvtColor(matDst1, matDst1, COLOR_BGR2GRAY);
    cvtColor(matDst2, matDst2, COLOR_BGR2GRAY);

    int iAvg1 = 0, iAvg2 = 0;
    int arr1[64], arr2[64];

    for (int i = 0; i < 8; i++) {
        uchar *data1 = matDst1.ptr<uchar>(i);
        uchar *data2 = matDst2.ptr<uchar>(i);

        int tmp = i * 8;

        for (int j = 0; j < 8; j++) {
            int tmp1 = tmp + j;

            arr1[tmp1] = data1[j] / 4 * 4;
            arr2[tmp1] = data2[j] / 4 * 4;

            iAvg1 += arr1[tmp1];
            iAvg2 += arr2[tmp1];
        }
    }

    iAvg1 /= 64;
    iAvg2 /= 64;

    for (int i = 0; i < 64; i++) {
        arr1[i] = (arr1[i] >= iAvg1) ? 1 : 0;
        arr2[i] = (arr2[i] >= iAvg2) ? 1 : 0;
    }

    int iDiffNum = 0;

    for (int i = 0; i < 64; i++) {
        if (arr1[i] != arr2[i]) {
            ++iDiffNum;
        }
    }
    return iDiffNum;
}

///////////////////////////////////////////////////////////

if (lastMat.rows > 0) {

    int iDiffNum = getSimilarity(matROI_IDCard, lastMat);

    if (iDiffNum > 10) {
        result += "画面抖动，请拿稳手机" + getString(iDiffNum);
        lastMat = matROI_IDCard;
        similarityCount = 0;
        return env->NewStringUTF(result.c_str());
    } else {
        similarityCount++;
        if(similarityCount < 2)
        {
            result += "画面抖动，请拿稳手机" + getString(iDiffNum);
            //lastMat = matROI_IDCard;
            return env->NewStringUTF(result.c_str());
        }
    }
}

similarityCount = 0;
lastMat = matROI_IDCard;