5. The paper-sheet recognition apparatus according to claim 1 , wherein the type determining unit handles the image data in units of blocks of a predetermined size, each block being a set of pixels, and determines one type based on the block, and the candidate narrowing-down unit handles the image data in the units of blocks, each block being larger than the predetermined size, and narrows down the number of type candidates of the paper sheet based on the block.
1. A paper-sheet recognition apparatus that recognizes a paper sheet, the paper-sheet recognition apparatus comprising: a paper-sheet information acquisition unit that acquires paper-sheet information including an image data of the paper sheet; a candidate narrowing-down unit that narrows down a number of type candidates of the paper sheet to a small number of types based on the image data included in the paper-sheet information; a type determining unit that determines one type from the type candidates narrowed down by the candidate narrowing-down unit based on the image data included in the paper-sheet information; an authenticity recognition unit that recognizes authenticity of the paper sheet as to each of the type candidates narrowed down by the candidate narrowing-down unit; an execution instructing unit that issues an instruction such that the type determining unit and the authenticity recognition unit are operated concurrently; and a final judgment unit that performs a final judgment on the paper sheet by combining the type determined by the type determining unit and an authenticity recognition result corresponding to the type from among authenticity recognition results of the candidate types recognized by the authenticity recognition unit.