Deep Learning-based Face Super-resolution: A Survey

Face super-resolution, also known as face hallucination, which is aimed at enhancing the resolution of low-resolution (LR) one or a sequence of face images to generate the corresponding high-resolution (HR) face images, is a domain-specific image super-resolution problem. Recently, face super-resolution has received considerable attention, and witnessed dazzling advances with deep learning techniques. To date, few summaries of the studies on the deep learning-based face super-resolution are available. In this survey, we present a comprehensive review of deep learning techniques in face super-resolution in a systematic manner. First, we summarize the problem formulation of face super-resolution. Second, we compare the differences between generic image super-resolution and face super-resolution. Third, datasets and performance metrics commonly used in facial hallucination are presented. Fourth, we roughly categorize existing methods according to the utilization of face-specific information. In J. Jiang School of Computer Science and Technology, Harbin Institute of Technology Harbin 150001, China E-mail: jiangjunjun@hit.edu.cn C. Wang School of Computer Science and Technology, Harbin Institute of Technology Harbin 150001, China E-mail: wangchy02@hit.edu.cn X. Liu School of Computer Science and Technology, Harbin Institute of Technology Harbin 150001, China E-mail: csxm@hit.edu.cn J. Ma Electronic Information School, Wuhan University Wuhan 430072, China E-mail: jyma2010@gmail.com each category, we start with a general description of design principles, present an overview of representative approaches, and compare the similarities and differences among various methods. Finally, we envision prospects for further technical advancement in this field.