color_pick_hsv

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

Mat im_hsv;
void pick_color(int e, int x, int y, int s, void *)
{
    if (e==1)
    {
        cerr << im_hsv.at<Vec3b>(y,x) << endl;
    }
}

int main( int argc, char** argv )
{
    namedWindow("blue");
    setMouseCallback("blue", pick_color);

    String c_in = "."; // check a whole folder.
    if (argc>1) c_in = argv[1];
    vector<String> fn;
    glob(c_in, fn, true);
    for(size_t i=0; i<fn.size(); i++)
    {
        Mat im_bgr = imread(fn[i]);
        if (im_bgr.empty()) continue;
        cvtColor(im_bgr, im_hsv, COLOR_BGR2HSV);
        imshow("blue", im_bgr);
        waitKey();
    }
    return 0;
}