| 摘要 |
PURPOSE:To decide whether a bill is genuine or false by converting an electric signal of a color image printed on the bill into a digital signal, and comparing a histogram of density generated from the digital signal with a true histogram generated on the basis of a color image of a true bill. CONSTITUTION:A color correcting circuit 49 converts a 10-bit RGB signal into an 8-bit signal and outputs it. A density histogram calculating circuit 51 generates histograms of an R component, a G component, and a B component from the corrected 8-bit RGB signal and a histogram of a gray component composed of the RGB signal. A bill outward shape size calculating circuit 53 calculates the lateral size and longitudinal size of the bill. A bill basic information table 55 records data on the histograms of the R, G, and B, and gray components, and outward shape sizes of various true bills in a memory. A genuine/false decision circuit 57 decides whether or not a bill is genuine, according to the density histogram data on the bill and the calculation data of the bill outward shape size. |
