Patent ID: 8854685

Claim:
An image determination device comprising: a sheet detecting unit that detects a sheet on which a code image is printed from sheets supplied to a transport path to form an image thereon; a first acquiring unit that acquires information on the code image printed on the sheet and an absorption wavelength of the code image; a second acquiring unit that acquires a reading unit necessary for decoding a code portion of the code image; a third acquiring unit that acquires a document image of an electronic document serving as an image formation target; a dividing unit that divides the document image acquired by the third acquiring unit into a plurality of blocks corresponding to the reading unit based on the reading unit of the code image acquired by the second acquiring unit; a detecting unit that detects an undecodable block based on the information of the code image acquired by the first acquiring unit, wherein the undecodable block comprises a block that contains an image portion of the document image that uses a color having an absorption band at the absorption wavelength of the code image and that contains the code portion of the code image; an output unit that outputs a warning indicating the generation of an undecodable area based on a result of the detection by the detecting unit, wherein, when the undecodable block is detected, a color conversion unit performs a color conversion process on the document image so that image portion of the document image that uses a color having an absorption band at the absorption wavelength of the code image is formed using a colorant that is devoid of an absorption band at the absorption wavelength of the code image.