I am confused at how to get the confidence level when using HOG GPU implementation in OpenCV 3.
According to OpenCV 3.1 cv::cuda::HOG::detectMultiScale Documentation, code replicated below:
virtual void
cv::cuda::HOG::detectMultiScale(InputArray img,
std::vector<Rect>& found_locations,
std::vector<double>* confidences = NULL)
You can pass a pointer to the third argument confidences. I've tried it but got OpenCV Error: Assertion failed (confidence == NULL || group_threshold_ == 0).
Looking at the actual implementation (hog.cpp:385), it is checking the confidences and only allowing a NULL parameter (code replicated below):
CV_Assert( confidences == NULL || group_threshold_ == 0 );
The same question has also been asked on StackOverflow and hasn't been addressed. Please advice.