Premium
Quantifying the visual appearance of sunscreens applied to the skin using indirect computer image colorimetry
Author(s) -
Richer Vincent,
Kharazmi Pegah,
Lee Tim K.,
Kalia Sunil,
Lui Harvey
Publication year - 2018
Publication title -
photodermatology, photoimmunology and photomedicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.736
H-Index - 60
eISSN - 1600-0781
pISSN - 0905-4383
DOI - 10.1111/phpp.12361
Subject(s) - colorimetry , visibility , digital photography , photography , artificial intelligence , computer science , dermatology , skin color , color space , mathematics , computer vision , computer graphics (images) , chemistry , optics , medicine , art , physics , image (mathematics) , visual arts
Summary Background There is no accepted method to objectively assess the visual appearance of sunscreens on the skin. Methods We present a method for sunscreen application, digital photography, and computer analysis to quantify the appearance of the skin after sunscreen application. Four sunscreen lotions were applied randomly at densities of 0.5, 1.0, 1.5, and 2.0 mg/cm 2 to areas of the back of 29 subjects. Each application site had a matched contralateral control area. High‐resolution standardized photographs including a color card were taken after sunscreen application. After color balance correction, CIE L*a*b* color values were extracted from paired sites. Differences in skin appearance attributed to sunscreen were represented by ΔE, which in turn was calculated from the linear Euclidean distance within the L*a*b* color space between the paired sites. Results Sunscreen visibility as measured by median ΔE varied across different products and application densities and ranged between 1.2 and 12.1. The visibility of sunscreens varied according to product SPF , composition (organic vs inorganic), presence of tint, and baseline b* of skin ( P < .05 for all). Conclusion Standardized sunscreen application followed by digital photography and indirect computer‐based colorimetry represents a potential method to objectively quantify visibility of sunscreen on the skin.