qrcam.cpp

/** @file qrcam.cpp
* Reading QR code using webcam
* and printing at terminal
* only once.
*/

#include <iostream>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <unistd.h>
#include <zbar.h>

#include "qrmosq.h"

using namespace cv;
using namespace std;
using namespace zbar;

//int main(void)
string qrMqtt::qrcam()
{
    string qrdata;
    VideoCapture cap(0);

    if (!cap.isOpened())
    {
		cerr << "Cannot open Webcam\n";
		//return -1;
		throw "#FAILED";
    }

    ImageScanner scanner; // zbar::ImageScanner
    scanner.set_config(ZBAR_NONE, ZBAR_CFG_ENABLE, 1);

    while (1)
    {
		Mat frame; // Mat - opencv n-dimension array class.
		bool bSuccess = cap.read(frame);
		if (!bSuccess)
		{
			cout << "cannot read a frame video\n";
			break;
		}

		Mat gray;
		cvtColor(frame, gray, CV_BGR2GRAY); // convert frame array to grey
							// as transform RGB space to GRAY.
		int width = frame.cols;
		int height = frame.rows;
		uchar *raw = (uchar *)gray.data;

		Image image(width, height, "Y800", raw, width * height); // zbar::Image::Image()
									// Y800 = 8 bit monochrome format.
									// GRAY also accepted.

		int n = scanner.scan(image);

		for (Image::SymbolIterator symbol = image.symbol_begin();
			symbol != image.symbol_end(); ++symbol)
		{
			qrdata = symbol->get_data();
			cout << "Main Data ->" << qrdata << endl;
		}

		if (!qrdata.empty())
		{
			break;
		}
		usleep(100000);
    }
    return qrdata;
}