Quantification of Facial Pores Using Image Analysis
François G, Maudet A, McDaniel D, Giron F, Bazin R
A common complaint related to aging in women concerns the widening of facial pores. To evaluate the severity of the phenomenon, the authors developed a device called Dermascore that enables pores to be visualized, photographed, and evaluated with an associated scale. Quantitative evaluation was performed on the pictures using a specific image analysis algorithm that allows the number and size of pores to be measured. The purpose of the study was to validate evaluation through image analysis in comparison with visual evaluation. Dermascore photographs of the cheek were taken of 150 women aged 18 to 70 years and evaluated by an expert panel with the grading scale used in standardized conditions. The relationship between the scores and the computed results was studied using linear regression analysis followed by a Pearson product moment correlation. The algorithm allows the selection of pores whose diameter was more than a chosen threshold value. When the threshold is 100 μm, 250 μm, and 500 μm, the correlation coefficient between visual evaluation and calculated pore size was respectively 0.66, 0.76, and 0.60. The image analysis procedure evaluated the size of facial pores independently of their number, and the most relevant threshold value is 250 μm to better fit the experts’ judgment.