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Phase shifting profilometry (PSP) has been widely used in many fields of application due to its accuracy and precision in obtaining depth information of a surface. One of the many applications that can take advantage of phase shifting profilometry is skin imaging, where PSP can be beneficial in efficacy testing of a certain cosmetic product, scar healing monitoring, etc. The simplicity of digital phase shifting profilometry hardware configuration further support the use of this technology for skin imaging application. Even though PSP and other interferogram based measurement is well known of its insensitivity to background lighting—because of its utilization of structured light pattern as light modulator—in practice, light interaction with surface finish still contributes to error to some extent. In this paper, the combination of frequency filter and spatial filtering is used to compensate that problem as preprocessing step prior to phase analysis. A simple Butterworth bandpass filter is used to isolate the first order harmonic containing modulation information, followed by Mean Curvature Diffusion to eliminate illuminance noise due to reflection from skin surface. Validation of this method was carried out by testing samples of leather having different textures.
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