I. INTRODUCTION

II. OVERVIEW
A. Notations and Definitions
B. Different Settings of Domain Adaptation

III. APPROACHES OF DEEP DOMAIN ADAPTATION
A. Categorization of One-Step Domain Adaptation
B. Categorization of Multi-Step Domain Adaptation

IV. ONE-STEP DOMAIN ADAPTATION
A. Homogeneous Domain Adaptation
B. Heterogeneous Domain Adaptation

V. MULTI-STEP DOMAIN ADAPTATION
A. Hand-Crafted Approaches
B. Instance-Based Approaches
C. Representation-Based Approaches

VI. APPLICATION OF DEEP DOMAIN ADAPTATION
A. Image Classification
B. Face Recognition
C. Object Detection
D. Semantic Segmentation
E. Image-to-Image Translation
F. Person Re-identification
G. Image Captioning

VII. CONCLUSION