CCS Concepts: 
• General and Reference → Surveys and Overviews;  
• Computing Methodologies → Reconstruction; Neural Networks.

1. INTRODUCTION

2. PROBLEM SETTING AND RELATED WORKS  
2.1 Problem Definition  
2.2 Benchmark Datasets  
2.3 Upsampling Methods  
2.4 Optimization Objective  
2.5 Assessment Methods  

3. IMAGE SUPER-RESOLUTION  
3.1 Simulation SISR  
3.2 Perceptual Quality Methods  
3.3 Information Utilization Methods  
3.4 Real-World Image Super-Resolution  
3.5 Domain-Specific Applications  

4. RECONSTRUCTION RESULTS

5. REMAINING ISSUES AND FUTURE DIRECTIONS  
5.1 Lightweight SISR for Edge Devices  
5.2 Flexible and Adjustable SISR  
5.3 New Loss Functions and Assessment Methods  
5.4 Mutual Promotion with High-Level Tasks  
5.5 Efficient and Accurate Real SISR  
5.6 Efficient and Accurate Scale Arbitrary SISR  
5.7 Consider the Characteristics of Different Images  

6. CONCLUSION