562015-03-24 , 法政大学大学院理工学・工学研究科
In this study, we investigated a preliminary assessment method for skin conditions such as a moisturizing property and skin fineness with an image analysis only. We captured facial spot images from volunteer subjects aged between 20s and 60s with Pocket Micro device (Scalar Co., Japan). This device has two image capturing modes; the normal mode and the non-reflection mode with the aid of the equipped polarization filter. We captured skin images from a total of 147 spots from subjects' face using both modes (i.e. total of 294 skin images). The moisture-retaining property of the skin and subjective evaluation score of the skin fineness in 5-point scale for each case were also obtained in advance as a gold standard (their mean and SD were 36.45 ± 3.13 and 3.45 ± 1.17, respectively). We extracted a total of 162 image features from each image and built linear regression models for estimating abovementioned criteria with a stepwise feature selection. The developed model in estimating the skin moisture achieved the MAE of 1.92 (μS) with 6 selected parameters, while the model for skin fineness achieved that of 0.51 scales with 7 parameters under the leave-one-out cross validation. We confirmed the developed models predicted the moisture-retaining property and fineness of the skin appropriately with only captured image.