Analysis of human perception of facial skin radiance by means of image histogram parameters of surface and subsurface reflections from the skin

Background The appearance of the skin is the result of complicated lightskin interactions involving surface and subsurface reflections. Radiant skin is a complicated attribute but is important for skin beauty. The aim of the present study was to achieve an understanding of the association between human perceptions of skin radiance and image histogram parameters from technically recorded images of surface and subsurface reflections. Methods Facial images of 45 subjects were evaluated visually by 30 respondents and were also computer analyzed in terms of their image histogram parameters. A partial least squares regression model was created to explain visual perceptions in terms of the image histogram parameters. Results Visual perceptions of subsurface reflections can be explained in terms of the mean from the subsurface reflection image histogram, and visual perceptions of surface reflections can be explained in terms of the standard deviation (SD) and skewness from the surface reflection image histogram. Skin radiance can be explained in terms of the mean from the subsurface reflection and the SD from the surface reflection. Conclusion To acquire skin radiance, a surface reflection component that makes the skin look shiny and a subsurface reflection component that is in line with skin fairness are both needed. A balance of these features provides the origin of skin radiance.