C++/GIMP/OpenCV

[PowerThreads]

Can you please clarify which chunk stands for UnsharpMask?
Using peace of code below, but it's not the same even close

Code:

#include "opencv2/core.hpp"
#include "opencv2/imgproc.hpp"
#include "opencv2/highgui.hpp"
#include <cstring>

cv::Mat not_so_smart_sharpen(
        const cv::Mat& bgr,
        double sigma,
        double amount,
        double canny_low_threshold_weight,
        double canny_high_threshold_weight,
        int edge_weight)
{
    cv::Mat enhanced_bgr, lab, enhanced_lab, channel[3], blurred, difference, bw, kernel, edges;

    // convert to Lab
    cv::cvtColor(bgr, lab, cv::ColorConversionCodes::COLOR_BGR2Lab);
    // perform the enhancement on the brightness component
    cv::split(lab, channel);
    cv::Mat& brightness = channel[0];
    // smoothing for unsharp masking
    cv::GaussianBlur(brightness, blurred, cv::Size(0, 0), sigma);
    difference = brightness - blurred;
    // calculate an edge map. I'll use Otsu threshold as the basis
    double thresh = cv::threshold(brightness, bw, 0, 255, cv::ThresholdTypes::THRESH_BINARY | cv::ThresholdTypes::THRESH_OTSU);
    cv::Canny(brightness, edges, thresh * canny_low_threshold_weight, thresh * canny_high_threshold_weight);
    // control edge thickness. use edge_weight=0 to use Canny edges unaltered
    cv::dilate(edges, edges, kernel, cv::Point(-1, -1), edge_weight);
    // unsharp masking on the edges
    cv::add(brightness, difference * amount, brightness, edges);
    // use the enhanced brightness channel
    cv::merge(channel, 3, enhanced_lab);
    // convert to BGR
    cv::cvtColor(enhanced_lab, enhanced_bgr, cv::ColorConversionCodes::COLOR_Lab2BGR);

//  cv::imshow("edges", edges);
//  cv::imshow("difference", difference * amount);
//  cv::imshow("original", bgr);
//  cv::imshow("enhanced", enhanced_bgr);
//  cv::waitKey(0);

    return enhanced_bgr;
}

int main(int argc, char *argv[])
{
    double sigma = std::stod(argv[1]);
    double amount = std::stod(argv[2]);
    double low = std::stod(argv[3]);
    double high = std::stod(argv[4]);
    int w = std::stoi(argv[5]);

    cv::Mat bgr = cv::imread("flower.jpg");

    cv::Mat enhanced = not_so_smart_sharpen(bgr, sigma, amount, low, high, w);

    cv::imshow("original", bgr);
    cv::imshow("enhanced", enhanced);
    cv::waitKey(0);

    return 0;
}

---

Other piece of code:

Code:

int main()
{
cv::Mat bgr = cv::imread("/home/supernova/Desktop/1tess2.jpg");
cv::Mat image;
cv::GaussianBlur(bgr, image, cv::Size(0, 0), 3);
cv::imshow("GaussianBlur", image);
cv::waitKey(100);
cv::addWeighted(bgr, 1.2, image, 0, 0.2, image);
cv::imshow("enhanced", image);
cv::waitKey(0);
cv::imwrite("/home/supernova/Desktop/1tessNew.jpg", image);
}

it does something, which is not relevant to what unsharpMask does, maybe I need to set some specific values?
if so, please advise what values I need to set