An imaging unit capturing an image of a body surface with near-infrared light while changing a magnification, and generating multiple pieces of near-infrared light imaging data having different magnifications, a vein pattern extraction unit extracting multiple vein patterns corresponding to each of the multiple pieces of the near-infrared light imaging data from each of the multiple pieces of the near-infrared light imaging data, a fractal dimension calculation unit calculating a fractal dimension corresponding to each of the vein patterns for the extracted multiple vein patterns, 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 calculated fractal dimension are provided.
