According to OpenCV 3.0 docs cv::HoughLines can stablish min and max theta for searching: min_theta – [...] Must fall between 0 and max_theta. max_theta – [...] Must fall between min_theta and CV_PI.
Then, you can't set angle search over PI making impossible to search the PI to 2 PI half rect space.
I think there is something I am missing, or the polar representation in that Hough Transform is not like I think should be.
My goal is to search only near vertical or near horizontal lines. ¿Can I do that with min and max theta?