Illumination-independent Color Reproduction in Medicine and Its Evaluation

A system of illuminant-independent color reproduction has been developed for practical use in medicine, and its performance was subjectively evaluated by a group of healthcare professionals of various specialties. For medical diagnosis, it is important to archive image data of diseased skin for the purpose of visually reviewing its chronological changes. However, sufficient color reproduction quality has never developed for this purpose. First, the illuminant conditions at various locations in a university hospital were measured and it was found that illuminants used in the hospital have a wide range of colors and that some of them have color rendering index (Ra) values that are too low for ordinary colorimetric color reproduction. Therefore, the multi-spectral imaging technique was applied for the illuminant-independent color reproduction to correct the color adaptively to the various kinds of illuminant. The healthcare professionals group evaluated the reproduced skin color by comparing the images with real skin. The results verify the effectiveness of the developed system and also expose the medical need for shading reproduction in addition to averaged color reproduction