There are several methods of face detection, and they can be broadly classified into two categories: traditional methods and deep learning-based methods.
– Traditional Face Algorithm Methods
Traditional methods in face detection include techniques such as Viola-Jones algorithm, Local Binary Patterns (LBP), and Histograms of Oriented Gradients (HOG). Viola-Jones algorithm is a popular method that uses Haar-like features and a cascading classifier to detect faces [2]. LBP is a texture-based method that extracts features from an image and uses them to detect faces. HOG is a feature-based method that uses gradient orientation histograms to detect faces.
– Deep Learning-Based Methods
Deep learning-based methods use Convolutional Neural Networks (CNNs) to detect faces. These methods have achieved state-of-the-art performance in face detection, and they include Single Shot Detector (SSD), Region-based CNN (R-CNN), and You Only Look Once (YOLO). SSD is a real-time method that uses a single CNN to predict the location and size of faces in an image. R-CNN is a region-based method that uses a CNN to classify regions of an image as containing a face or not, and then uses a bounding box regression to refine the face location. YOLO is a real-time method that uses a single CNN to predict the location and size of faces in an image, and it achieves high accuracy and speed.
Overall, traditional methods and deep learning-based methods have their strengths and weaknesses. Traditional methods are computationally efficient and can work well in low-resolution images, but they may not perform well in complex environments with varying lighting conditions and facial expressions. In contrast, deep learning-based methods used in face detection software can achieve high accuracy and robustness in complex environments, but they require large amounts of training data and are computationally intensive.