Digital image matting is the process of softly fetching foreground objects from an image. It has become a widely used application for editing the images and to give special effect in the film production industry. Reducing the cost in film making, giving special effect in movies and editing the images are the main motivations for matting. This paper provides a concise review of various approaches for solving matting problem. These approaches can be broadly categorized into two categories: Trimap-based and Scribble-based matting approaches. This paper also provides strengths and weaknesses of various approaches coming under these categories. Finally, the paper concludes with the comparative analysis of all approaches reviewed under both the categories.