An imaging unit capturing an image of a body surface with near-infrared light and generating near-infrared light imaging data, a vein pattern extraction unit extracting multiple kinds of near-infrared light vein patterns from one piece of the near-infrared light imaging data by applying a differential filter outputting a large value for a pixel having a large difference between the pixel and its surrounding pixel to multiple pixels constituting the near-infrared light imaging data and changing a parameter changing an output property of the differential filter, and a pseudo-vein pattern determination unit determining presence of a pseudo-vein pattern intentionally formed on a part of the captured body surface based on the extracted vein pattern are provided.
