Building Computer Vision Projects with OpenCV 4 and C++

Training mode

When the user finally clicks in the middle of the window, the face recognition algorithm will begin training on all the collected faces. But it is important to make sure there have been enough faces or people collected, otherwise the program may crash. In general, this just requires making sure there is at least one face in the training set (which implies there is at least one person). But the Fisherfaces algorithm looks for comparisons between people, so if there are less than two people in the training set, it will also crash. So, we must check whether the selected face recognition algorithm is Fisherfaces. If it is, then we require at least two people with faces, otherwise we require at least one person with a face. If there ...