In this chapter, we introduce the process of information perception in 2D facial images and elaborate on each step in detail. We begin with image preprocessing techniques such as face detection, landmark localization, cropping, and alignment. Then, we present common types of facial features and their corresponding extraction methods, including low-level features such as geometric and texture descriptors, as well as high-level features extracted by deep neural networks. Finally, we demonstrate and discuss the results of these feature extraction methods to enhance the reader’s understanding.