Converting a Common Document Scanner to a Multispectral Scanner
This work addresses the need for affordable and portable multispectral scanning in forensic and financial document verification, though it is incremental as it adapts existing scanner hardware.
The researchers tackled the problem of capturing multispectral images for document analysis by modifying a standard sheet-feed scanner with an external LED light source, resulting in a portable prototype capable of scanning documents under different wavelengths for applications like verifying questioned documents and bank notes.
We propose the construction of a prototype scanner designed to capture multispectral images of documents. A standard sheet-feed scanner is modified by disconnecting its internal light source and connecting an external multispectral light source comprising of narrow band light emitting diodes (LED). A document is scanned by illuminating the scanner light guide successively with different LEDs and capturing a scan of the document. The system is portable and can be used for potential applications in verification of questioned documents, cheques, receipts and bank notes.