Determining document fitness using illumination

A currency processing system for assessing the fitness of bank notes, the system comprising:

• a batch feed;
• a conveyer proximate the batch feed for moving notes from the batch feed;
• a plurality of sort bins proximate the conveyer for receiving notes;
• a control system;
• a plurality of illumination sources coupled to the control system and proximate the conveyer, wherein the plurality of illumination sources includes at least two different wavelengths of electromagnetic radiation;
• a line scan camera proximate the conveyer and coupled to the control system for capturing images in greyscale;
• and
• the control system including a memory and a processor, wherein the memory and processor are operable to perform the following steps:
• activate the plurality of illumination sources in a predetermined order, and
• use the line scan camera to capture image data associated with the predetermined order and saving the image data in memory, wherein the image data are captured at a same location on a note for each of the plurality of illumination sources.