Abstract
Forged documents and counterfeit currency can be better detected with multispectral imaging in multiple color channels instead of the usual red, green and blue. However, multispectral cameras/scanners are expensive. We propose the construction of a low cost scanner designed to capture multispectral images of documents. A standard sheet-feed scanner was modified by disconnecting its internal light source and connecting an external multispectral light source comprising of narrow band light emitting diodes (LED). A document was scanned by illuminating the scanner light guide successively with different LEDs and capturing a scan of the document. The system costs less than a hundred dollars and is portable. It can potentially be used for applications in verification of questioned documents, checks, receipts and bank notes.
Highlights
Forensic analysis of questioned documents involves a broad range of activities [1]
We present the design of a prototype multispectral document scanner, which is demonstrated to capture subtle features in a document using a multispectral light source
The multispectral light source was designed to cover the full range of visible electromagnetic spectrum and connected to a portable sheet-feed document scanner
Summary
Forensic analysis of questioned documents involves a broad range of activities [1]. This includes establishing whether a document originated from a particular source, is backdated, forged or willfully manipulated. A snapshot spatio-spectral sensor simultaneously captures both spatial and spectral ( x, y, λ) dimensions of a scene eliminating the need for scanning [16] This method can effectively be used in conditions where the scene and the sensing platform are simultaneously moving. We propose a spatio-spectral scanner for capturing multispectral image of a document using a sheet-feed scanner, avoiding the problems associated with cameras. It captures one spatial dimension x, whereas the (y, λ) dimensions are sequentially acquired by feeding the document and tuning illumination spectrum, respectively. We describe the proposed multispectral document scanning system, in terms of its electrical, spectral and optical design
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
