Method and apparatus for detecting the presence of dermal melanin in epithelial tissue

摘要

An image of an individual (2) is obtained using a digital camera (1). The image data is then processed by ratio determination module (10) and an image conversion module (12) to analyse the image and determine data representative of the distribution of blood and melanin in the skin of the imaged individual. This chromophore distribution data is then processed by an image generation module (18) which generates an image representative of the expected appearance of epithelial tissue having the determined distribution of chromophores where the epithelial tissue is under fixed illumination and has a flat spatial geometry and where all the identified melanin is present solely in the epidermis. The presence of dermal melanin can then be identified by comparing the original image data and the image derived from processing the calculated chromophore distributions and identifying where the ratio of these images differs by more than a threshold, the threshold being set at a level above the amount of variation expected due to lighting and geometry differences.