Binarization of pre-filtered
historical manuscripts images
Ntogas Nikolaos
Department of Computer Science Technology and Telecommunications,
TEI of Larisa, Larisa, Greece and
Faculty of Computing Engineering and Technology, Staffordshire University,
Stoke on Trent, UK, and
Ventzas Dimitrios
Department of Computer Science Technology and Telecommunications,
TEI of Larisa, Larisa, Greece
Abstract
Purpose – The purpose of this paper is to introduce an innovative procedure for digital
historical documents image binarization based on image pre-processing and image condition
classification. The estimated results for each class of images and each method have shown
improved image quality for the six categories of document images described by their separate
characteristics.
Design/methodology/approach – The applied technique consists of five stages, i.e. text image
acquisition, image preparation, denoising, image type classification in six categories according to
image condition, image thresholding and final refinement, a very effective approach to binarize
document images. The results achieved by the authors’ method require minimal pre-processing steps
for best quality of the image and increased text readability. This methodology performs better
compared to current state-of-the-art adaptive thresholding techniques.
Findings – An innovative procedure for digital historical documents image binarization based on
image pre-processing, image type classification in categories according to image condition and further
enhancement. This methodology is robust and simple, with minimal pre-processing steps for best
quality of the image, increased text readability and it performs better compared to available
thresholding techniques.
Research limitations/implications – The technique consists of limited but optimized
pre-processing sequential steps, and attention should be given in document image preparation and
denoising, and on image condition classification for thresholding and refinement, since bad results in a
single stage corrupt the final document image quality and text readability.
Originality/value – The paper contributes in digital image binarization of text images suggesting a
procedure based on image preparation, image type classification and thresholding and image
refinement with applicability on Byzantine historical documents.
Keywords Image processing, Archiving, Classification, Digital storage
Paper type Technical paper
The current issue and full text archive of this journal is available at
www.emeraldinsight.com/1756-378X.htm
The authors would like to thank the Department of Computer Science and Telecommunications
Technology, at TEI Larisa, Greece, for their support during this work and the Monks of Holy
Monastery of Dousiko, near Meteora, Greece, who gave them the opportunity to have access to
Historical Manuscript “Codices” that are kept in their Monastery and dated since 1611 AD. Also,
they would like to thank Professor N. Papamarkos for providing algorithms for comparison with
their method.
IJICC
2,1
148
Received 5 January 2008
Revised 22 June 2008
Accepted 14 July 2008
International Journal of Intelligent
Computing and Cybernetics
Vol. 2 No. 1, 2009
pp. 148-174
q Emerald Group Publishing Limited
1756-378X
DOI 10.1108/17563780910939282