How face detection is achieved using haarcascade_frontalcatface.xml
I want to know that how face detection is achieved in opencv using haarcascade_frontalcatface.xml files. As viola-jones face detector is implemented in opencv for face detection and it needs to be trained before testing. So my question is it trained primarily and some model is stored in these xml files or it is trained just when function is invoked for testing. If it is trained primarily then how training results are stored in these xml files. Please help! Thanks in advance.
maybe this topic helps
those xml files are pre-trained models. see tutorials on how to use or train them.
Like @sturkmen linked, I have visualisations and explanations lying around. The book is officially published on monday and then I will put my open source work into the library. How the cat detector was trained, can be read in the book of Joe Howse, OpenCV for secret agents. He trained those models.