| 摘要 |
<p>A method and system are disclosed for detecting an amount of soiling of a bill (1). The method includes steps of (A) illuminating at least a portion of the bill with excitation light (8); in response to the excitation light, (B) emitting response light from the portion of the bill; (C) detecting an intensity of the emitted response light; and (D) correlating the detected intensity with an amount of soiling (4) of the bill. The method can include a further step of (E) correlating the amount of soiling with an amount of wear of the bill, and may also further include a step of (F) detecting a presence of a substantially specular surface region on the bill, indicating a presence of a foreign substance, such as a piece of transparent or semitransparent tape. Also disclosed is a method and system for detecting a presence of a foreign substance on a surface of a bill. The method includes steps of (A) illuminating at least a portion of the bill with light; in response to the light, (B) causing either a specular reflection or a diffuse reflection from a surface of the bill; (C) detecting a presence of a specular reflection; and (D) correlating the detected specular reflection with the presence of a foreign substance, such as tape, on the bill. An amount of polarization contrast can also be determined for detecting a presence of a foreign matter, such as tape, on the surface of the bill.</p> |
