I. Introduction  
II. Segmentation Cues  
III. Graph Based Optimization Frameworks  
IV. Object Elements Based Non-Deep Co-Segmentation  
V. Object Regions / Contours Based Non-Deep Co-Segmentation  
VI. Common Object Model Based Non-Deep Co-Segmentation  
VII. Deep Co-Segmentation  
VIII. Algorithm Evaluations  
IX. Discussions  
X. Conclusions