ca.smum@tminyerhaB Shahrokh Nasseri Medical Physics Research Center, Medical Physics Department, high throughput chemical screening Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran Tel: 098 5138002328 Fax: 098 5138002320 Postal address: Department of Medical Physics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran. E-mail: ri.ca.smum@hsiresan; [email protected]

ACKNOWLEDGMENTS This research project was supported by a grant from Vice Chancellor for Research at Mashhad University of Medical Sciences, Mashhad, Iran. Footnotes Source of Support: Nil Conflict of Interest: None declared
Melanoma is a malignant pigmented skin lesion which is the deadliest type of skin cancer in the world. This cancer is the sixth most common cancer among American men and women and is the main factor of cancer death in 25-30 years old women. Also, melanoma is the most common type of cancer in 20-44 years old men in Australia and New Zealand.[1] In Iran, according to the 8877 cases of skin cancer in 2006, this type of cancer was

known as the first cancer.[2] On the other hand, moles that are natural parts of the skin are benign types of pigmented skin lesions. Characteristics of both benign and malignant pigmented skin lesions are similar which makes differentiating between them a challenging problem.[3] Dermoscope lens and conventional digital camera are the most commonly used equipments that are used to investigate characteristics of pigmented skin lesions. The usage of each one of these equipments has advantages and disadvantages. The visualization of subsurface microstructures of the epidermis and upper dermis

and uniform illumination are among the benefits of dermoscopic images but, on the other hand, the dermoscopy lens is not publicly available.[4,5] While nowadays, conventional digital cameras with spatial resolution higher than one megapixel are widely used by the general public and the taken images which are called macroscopic or clinical images are nonuniformly illuminated. Figure 1 shows macroscopic and dermoscopy images of an invasive melanoma. In this figure, the differences between visible characteristics of the two mentioned types of image, is clear. So, various computer processing techniques must be used Entinostat for their analysis.[3] Figure 1 An invasive melanoma (a) Macroscopic image, (b) Dermoscopic image The ultimate goal of procedures that are developed to distinguish between benign and malignant pigmented skin lesions is simplicity of applying by nonexperts and the general public. Hence, such procedures should be developed for macroscopic images with minimum constraints of imaging conditions. Some of these conditions include the usage of special resolution camera, considering a predetermined distance between camera and skin surface, and the usage of flash light during imaging. Up to now, studies in this area have been done assuming the above conditions and constraints are applied on the databases.