Performance of the 14 skin-colored patches in accurately estimating human skin color

Abstract

This research examined the performance of skin colored-patches for accurately estimating human skin color. More than 300 facial images of Korean females were taken with a digital single-lens reflex camera (Canon 550D) while each was holding the X-Rite Digital ColorChecker® semi-gloss target. The color checker consisted of 140 color patches, including the 14 skin-colored ones. As the ground truth, the CIE 1976 Lab values of seven spots in each face were measured with a spectrophotometer. For an examination, three sets of calibration targets were compared, and each set consisted of the whole 140 patches, 24 standard color patches and 14 skin-colored patches. Consequently, three sets of estimated skin colors were obtained, and the errors from the ground truth were calculated through the square root of the sum of squared differences (AE). The results show that the error of color correction using the 14 skin-colored patches was significantly smaller (average ΔE = 8.58, SD = 3.89) than errors of correction using the other two sets of color patches. The study provides evidence that the skin-colored patches support more accurate estimations of skin colors. It is expected that the skin-colored patches will perform as a new standard calibration target for skin-related image calibration.