OCR at BnF : history, production, projects, research

Geneviève Cron• Bibliothèque Nationale de France

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• 1992 today : • digitization tenders + internal programs

• 2005 today : • digitization + OCR-isation tenders• OCR-isation tenders

• 2010 today : • OCR + EPub• digitization + OCR + Epub

• Image quality• OCR output

BnF/OCR/Production/History

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BnF/OCR/Production/History

0

500 000

1 000 000

1 500 000

2 000 000

2 500 000

1980 1985 1990 1995 2000 2005 2010 2015 2020

DigitizedOCR-isedEpub

BnF/OCR/Production/Workflow

OCR

Selection Digitization OCR-ization

Control Eval

Selection

Bnf/OCR/Research/Master2010

OCR

OCR Rate

Prediction

> X %

YES

NO

XX

Litis +

Bnf/OCR/Research/PhD2010

OCR

OCR Rate

Prediction

> x % ?

YES

NO

X

Digitization

Bnf/OCR/Research/Digidoc

• Digidoc : – Optimizing digitization as a function of the use :

• Conservation• OCR• Communication

– New metadata format• with information gathered in the digitization process• including data from image processing

OCRization

OCR

BnF/OCR/Production/OCR Workflow

OCR

Manual correction

> X %

[0% ,100%]

[X% ,100%]

[0% , 60%]

[60% ,100%]

ImageRaw OCR

OCR HQ

Service provider

X on word ? On character ?

• For digitized images– Internally produced– Produced in the early projects where no OCR where made (<

2004)

• Segmentation and segmentation correction• OCR and OCR correction / control

• Goal : 3 000 000 pages / year (2012)

• Actual status : test, settings, tunning

BnF/OCR/Production/OCR_Inhousing

Bnf/OCR/Research/Quaero

– BnF • provides corpus • for training and evaluation

– Research and development topics• Automatic and robust segmentation • Grayscale OCR • Reading ordre• Recognition on Maps• Manuscrit OCR• Named Entity Recognition

BnF/OCR/Research/Impact/BnF’s Goals

• Share experience on past and ongoing OCR workflows over Europe

• Take part in OCR Improvement– Improve the quality of the OCR output– Lower the post correction– Enlarge the material to be submitted to OCR

with good quality expectation

Bnf/OCR/Impact/BnF’s_Involvement

• Requirements• Evaluation

– Corpus defining and ground truth production and control– Evaluation criterias

• Case studies– BW / Greyscale– Destructive / Non destructive– OCR / Double Keyboarding

• Demonstrations, tests, servers for tools hosting• Center of competence

BnF/OCR/Research/Impact/Corpus

Surname Name # Bpp

Lang A 5893 Greyscale Language dataset17th centuryAbout Descartes

Dev

Eval

Demo

19th B 5139 Greyscale 99,9% in Alto format + Alto2Page conversion + manual correction

Newspaper C 200 Greyscale Newspaper

Theater D 34 Black & White Theater

Bad E 505 Black & White Bad quality image

Easy F 470 Black & White Easy book

Struct G 10 Black & White Complex structure

Bnf/OCR/Research/Impact/CorpusA=Lang

Bnf/OCR/Research/Impact/CorpusB=19th

Bnf/OCR/Research/Impact/CorpusC=Newspaper

Bnf/OCR/Research/Impact/CorpusE=Bad

Bnf/OCR/Research/Impact/CorpusF=Easy

Bnf/OCR/Research/Impact/CorpusG=Struct

Bnf/OCR/Research/Impact/RelatedTools

  Lang 19th Newspaper

Thea-tre

Bad Easy Struct

OCR (Abbyy + Tesseract) x x x x x x x

Collaborative Correction x x x x x x x

Structure analysis and correction

x x       x x

OCR post-correction x            

Binarisation & Colour Reduction

x x x        

Segmentations x x     x x  

Lexicon (French) / NE Repository

x            

Post Correction

OCR

BnF/OCR/Projects/Wikimedia partnership

http://fr.wikisource.org/wiki/Page:Anomyme_-_Raoul_de_Cambrai.djvu/82

Bnf/OCR/Production/Epub

• OCR is usefull for Image to EBook conversion

• About 200 EBooks from early tender • From images digitized in the 1990’s

• Paper material should be perfect• Image as well

• About 7 000 per year (2012)

Control and evaluation

Control Eval

Bnf/OCR/Research/OCR Evaluation

– OCR evaluation tool• PhD 2007

– OCR rates• Computation• Estimation• Control

• In a mass digitization context (no ground truth)

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BnF/OCR/Production/OCR Rates

98,6% !

BnF/OCR/Projects/Under Construction

• Recognition on – Music score (OMR)– Mediaval Manuscripts– Portolan charts and maps– Geolocalisation using OCR results

• Croudsourcing on Gallica

• XML Alto to Epub conversion

• Host Impact Center of Competence ?