Patent ID: 8270035

Claim:
An image processing device comprising: a generating unit that generates image data on the basis of which an image forming unit forms a visible image on a recording medium containing detectable substances using only a coloring material having a spectral reflection factor that is different in a particular wavelength range from a spectral reflection factor that the detectable substances have by a predetermined threshold or more; an output unit that outputs the image data generated by the generating unit to the image forming unit; a calculating unit that calculates a feature amount characterizing distribution of the detectable substances contained in the recoding medium; and a memory that stores the feature amount calculated by the calculating unit, wherein the detectable substances are embedded within the recording medium such that they do not protrude surfaces of the recording medium, and the calculating unit: obtains image information representing an image generated by reading the recording medium, extracts an image corresponding to the detectable substances from the obtained image information, and calculates, as the feature amount, on the basis of the extracted image corresponding to the detectable substances, numbers of detectable substances classified into angular ranges according to angles of predetermined extending directions of the detectable substances relative to the read surface of the recording medium.