Hard Limiting and Soft Computing Techniques for Detection of Exudates in Retinal Images: A Futuristic Review

Retinopathy in general, diabetic retinopathy in particular is the major concerns of blindness and appearance of hard exudates is one of its early symptoms. Since almost two decades, researchers are striving to develop automated algorithms and systems either to detect or to grade the severity of hard exudates. In this direction, this paper is a sincere effort to present the research carried out in this field. This paper has three specific intents i) to update the state- of-the-art techniques by bringing to the fore research that is being carried out, ii) to encourage prospective researchers in this area to explore various computational methodologies for the future development of detection techniques, and iii) to provide insights into some unsolved recognition problems.