Quantification of erythema using digital camera and computer‐based colour image analysis: a multicentre study

Background/purpose Colour measurements obtained from digitized images have been proposed as a simple and cost‐effective way to evaluate skin colour and the activity of treatments. The main disadvantage of the method is the fact that it is highly dependent on ambient light: even if an accurate control of subjects' illumination is provided, readings remain not comparable among different laboratories. The purpose of this study was to develop a highly reproducible system for computerized colour image analysis of skin erythema, making it possible to compare readings from different environmental light conditions.