Kiduino:
but as I'm a starter in OpenCV, Let me know what's gonna be the output (of the processed image?)
can i assign it on a variable to work with the further programming?
the output will be a colored line drawn over the line it detected (see the bottom of the page)
for( size_t i = 0; i < lines.size(); i++ )
{
 float rho = lines[i][0], theta = lines[i][1];
 Point pt1, pt2;
 double a = cos(theta), b = sin(theta);
 double x0 = a*rho, y0 = b*rho;
 pt1.x = cvRound(x0 + 1000*(-b));
 pt1.y = cvRound(y0 + 1000*(a));
 pt2.x = cvRound(x0 - 1000*(-b));
 pt2.y = cvRound(y0 - 1000*(a));
 line( cdst, pt1, pt2, Scalar(0,0,255), 3, CV_AA);
}
this is where the lines are drawn, so you can use those values to send to the arduino.
Mike