Study of nail unit using image processing methods

Digital image processing plays a key role in medical imaging. Nail diagnosis is one of the methods in Ayurveda, Homeopathy and traditional medicines to predict the diseases. Nails can reflect the present health condition, genetically inheritance information, and historical information of drug or alcohol usage for the past months or even a year, etc. This paper explores the existing research works related to nail plate and nail matrix as tool for bio-metric system, nail fold capillaries to identify the disease severity levels & affected organs, nail surface as evidence in forensic science to identify the chemical effects, nail samples to identify drug intake and abuse etc. So that, Nail is analyzed by various imaging types and processing algorithms to recognize the person's uniqueness, health condition and its history. This paper also identifies the research challenges and issues.