OpenCV實現失焦模糊圖像恢復(沒對焦圖片/圖像/影像)

資料來源: https://mp.weixin.qq.com/s/-b1wfvv1jdtnlXzy9BEpJA

計算PSF的代碼如下：

void calcPSF(Mat& outputImg, Size filterSize, int R)
{
    Mat h(filterSize, CV_32F, Scalar(0));
    Point point(filterSize.width / 2, filterSize.height / 2);
    circle(h, point, R, 255, -1, 8);
    Scalar summa = sum(h);
    outputImg = h / summa[0];
}

生成維納濾波的代碼如下：

void calcWnrFilter(const Mat& input_h_PSF, Mat& output_G, double nsr)
{
    Mat h_PSF_shifted;
    fftshift(input_h_PSF, h_PSF_shifted);
    Mat planes[2] = { Mat_<float>(h_PSF_shifted.clone()), Mat::zeros(h_PSF_shifted.size(), CV_32F) };
    Mat complexI;
    merge(planes, 2, complexI);
    dft(complexI, complexI);
    split(complexI, planes);
    Mat denom;
    pow(abs(planes[0]), 2, denom);
    denom += nsr;
    divide(planes[0], denom, output_G);
}

實現反模糊的代碼如下：

void filter2DFreq(const Mat& inputImg, Mat& outputImg, const Mat& H)
{
    Mat planes[2] = { Mat_<float>(inputImg.clone()), Mat::zeros(inputImg.size(), CV_32F) };
    Mat complexI;
    merge(planes, 2, complexI);
    dft(complexI, complexI, DFT_SCALE);
    Mat planesH[2] = { Mat_<float>(H.clone()), Mat::zeros(H.size(), CV_32F) };
    Mat complexH;
    merge(planesH, 2, complexH);
    Mat complexIH;
    mulSpectrums(complexI, complexH, complexIH, 0);
    idft(complexIH, complexIH);
    split(complexIH, planes);
    outputImg = planes[0];
}

調用步驟: 

void adjust_filter(int, void*) {
    Mat imgOut;

    // 偶数处理，神级操作
    Rect roi = Rect(0, 0, src.cols & -2, src.rows & -2);
    printf("roi.x=%d, y=%d, w=%d, h=%d", roi.x, roi.y, roi.width, roi.height);

    // 生成PSF与维纳滤波器
    Mat Hw, h;
    calcPSF(h, roi.size(), adjust_r);
    calcWnrFilter(h, Hw, 1.0 / double(snr));

    // 反模糊
    filter2DFreq(src(roi), imgOut, Hw);

    // 归一化显示
    imgOut.convertTo(imgOut, CV_8U);
    normalize(imgOut, imgOut, 0, 255, NORM_MINMAX);

    imwrite("D:/deblur_result.jpg", imgOut);
    imshow("deblur_result", imgOut);
}

圖像傅里葉變換

void fftshift(const Mat& inputImg, Mat& outputImg)
{
    outputImg = inputImg.clone();
    int cx = outputImg.cols / 2;
    int cy = outputImg.rows / 2;
    Mat q0(outputImg, Rect(0, 0, cx, cy));
    Mat q1(outputImg, Rect(cx, 0, cx, cy));
    Mat q2(outputImg, Rect(0, cy, cx, cy));
    Mat q3(outputImg, Rect(cx, cy, cx, cy));
    Mat tmp;
    q0.copyTo(tmp);
    q3.copyTo(q0);
    tmp.copyTo(q3);
    q1.copyTo(tmp);
    q2.copyTo(q1);
    tmp.copyTo(q2);
}