Preprints are manuscripts made publicly available before they have been submitted for formal peer review and publication. They might contain new research findings or data. Preprints can be a draft or final version of an author's research but must not have been accepted for publication at the time of submission.
The discovery of ink mismatch provides important clues
to pre-writing examiners to indicate whether a particular manuscript is written
by a specific pen, or if a particular part of a note (e.g., signature) is written
on a different ink compared to any other ink. In this paper, we show that the hyperspectral
image (HSI) of the handwritten notes differs between visually similar inks. For
this purpose, we have created the first hyperspectral data domain for a handwritten
image in various blue and black inks, containing 33 visual reference bands. In unsupervised
clustering technique, visual responses of inks fall into different groups to allow
the separation of two different inks from the text of the questions. The same method
when used in the RGB scan of these outputs fails to accurately distinguish the ink
because it is very difficult to separate the ink from the optical range. HSI overcomes
RGB deficiencies and allows better discrimination between inks.