Natural Language Processing: Arabic Cursive Handwriting Recognition Natural Language ...

93 Pages·2008·2.65 MB·English

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Preamble
Arabic
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– Part of the Semitic language family
One of the most spoken language in the world
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– Nearly 250 million people speak Arabic
Spoken outside Arabic countries
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– Over 600 000 people In the United States speak
Arabic
Give rise to other alphabets
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– Farsi, Urdu…
• spoken by millions of people from Iran, Pakistan,
India…
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Preamble
The work presented here is that of numerous
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researchers working with me…
– Najoua Ben Amara
– Samia Maddouri
– Afef Kacem
– Imen Ben Cheikh
– Hiba Khelil
– Mohamed Yazid Boudaren
– Nazih Ouwayed
– Christophe Choisy
– Umapada Pal
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Presentation outline
Introduction
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– Brief historic, specific applications
Writing characteristics
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– Those shared with Latin
– Proper to Arabic
Issues of cursive word recognition
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– Reading models
– Global word-based (holistic), Local letter-based
(analytical) approach, Hybrid approach
Language Processing
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– Some basic solutions for handwriting recognition
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Introduction
The field arose before the apparition of
computers
Maturity
Small devices
Intelligent pen
Price
Handwritten
forms
1st Postal
address reader
Forms
OCR in
industry
Working
Models
Patents on
OCR: blind
telegraph
1900 1916 1950 1965 1980 2008
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Today for Latin:
An industry and a real market
Material :
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– Scanners adapted to documents
We know
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– scan documents in a huge quantity,
preserving the image quality
– compress them, publish them on the net
– recognize by OCR and identify some
structure elements
But …
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– on very good quality documents
– rather recent, poor structure, printed,
– Handwriting:
• Just few work available for specific
applications: small vocabulary
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Introduction
Arabic
Started at 1980
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– increasing demand for information indexing and retrieval
Pioneers
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– A. Amin (Loria),
– M. Cheriet (ETS, Montreal),
– N. Ben Amara (ENIT)…
Today
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– Many Labs: REGIM (Sfax), LRI (Annaba), READ (Loria),
ETS (Montreal), CEDAR (USA), ISI (India)
Many dedicated sessions and workshops
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– IWFHR, ICFHR, CIFED, ICDAR, SACH’06
Several public datasets
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– IFN/ENIT, DARPA/SAIC, CENPARMI, Farsi-City…
• See Volker Märgner list
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Introduction
Arabic
Commercial Arabic OCR
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– Number of commercial Arabic OCR engines
• Sakhr's Automatic Reader: ~1500$
• Readiris from IRIS : ~500$
• Verus from NovoDynamics : ~1300$
• Omnipage
– Evaluation by UNLV
• Sakhr (90,33%), OmniPage (86.89%)
Open Source Arabic OCR projects
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– The Siragi project (started in 2005)
• Part of the Arabic Unix open source project
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Introduction
Some specific applications
Bank check recognition of courtesy amounts
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Introduction
Signature recognition,
verification, forgery detection…
M.A. Ismail et al.
V. K. Madasu et al.
Pattern Recognition, 33 (2000)
Pattern Recognition, 38 (2005)
Global and local features in boxes
Normalized vector angle (α) in boxes
Algorithms based on fuzzy concepts
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