Proposal and Quality Evaluation of Skin Imaging Using Smartphone and Ring Light with Polarizing Film

A method for skin image acquisition for cosmetic purposes using a smartphone camera is discussed. A simple construction using a commonly available ring light and a polarizing film is used to create an inexpensive method for capturing images comparable to those of expensive beauty and medical cameras. The use of a ring light stabilizes the light source, and a polarizing film mounted orthogonally to the ring light and lens eliminates skin reflection. Image quality was evaluated using the non-reference image quality evaluation model (Naturalness Image Quality Evaluator). We show that the proposed method provides resolution and image quality comparable to beauty and medical cameras.