Consistent Cutaneous Imaging With Commercial Digital Cameras

Abstract

To demonstrate how to improve the reproducibility and accuracy of digital images of the skin taken with commercially available digital cameras by transforming them to a standard color space, sRGB. Our computer algorithm transforms digital images to the standard sRGB color space. It is based on a card with a number of color squares with known colorimetric properties that is included in the image, thereby removing any ambiguity about the color information in the image. Reproducibility and accuracy of the method were assessed by comparing images of color squares with known colorimetric properties taken with different digital cameras at different exposures and zoom settings. Although calibrated images exhibit markedly improved precision and accuracy compared with noncalibrated images, all variability of the imaging process cannot be eliminated. With a little care and effort, a calibrated color chart, and computer software, it is possible to greatly improve the quality of clinical imaging in dermatology and possibly other fields of medicine.