I am currently working on object detection and before diving in I just tried the example demo tutorial from OpenCV. (You can see the tutorial code here: https://github.com/opencv/opencv/blob/master/samples/cpp/tutorial_code/objectDetection/objectDetection.cpp).
So, my problem is when I build the program, I see a gray frame as detection window. Here is a solution for python but I tried this solution and it did not work for me.
The resulted screen can be seen from this link.
Thanks