Coptic OCR:
Even better models and improvements
on user-friendliness
Eliese-Sophia Lincke (Humboldt-Universität zu Berlin)
eslincke@staff.hu-berlin.de
Digital Coptic 3, July 12-13, 2020 (online)

Overview•••

more fonts
Calamari: new and better OCR software (as compared to OCRopus)
OCR4all: a graphical user interface (GUI)E.-S. Lincke, Coptic OCR: Even better models and improvements on user-friendliness, Digital Coptic 3, July 12-13, 20202

Coptic OCR: Chronological overview since 2016
2016: presentation of OCRopus results at the Coptic Congress, Claremont
2018: Coptic OCR becomes an official project• 6 months PostDoc fellowship at the Göttingen Centre for Digital Humanities,
CampusLab Digitization and Computational Analytics (DCA)
PIs: Heike Behlmer, Marco Büchler, Camilla Di Biase-Dyson
2019: publication of the results of the fellowship and new tools• presentation at the 3rd international conference on Digital Access to Textual Cultural
Heritage (DATeCH) in Brussels (May)• publication (open access) in the conference proceedings: Lincke, Bulert & Büchler (2019)• testing new tool – Calamari• training data of more fonts, model training (OCRopus, Calamari)• presentation of new results in the Berlin Digital Classicist Seminar (November)
2020: testing new tool – OCR4all

E.-S. Lincke, Coptic OCR: Even better models and improvements on user-friendliness, Digital Coptic 3, July 12-13, 2020

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OCR workflow

E.-S. Lincke, Coptic OCR: Even better models and improvements on user-friendliness, Digital Coptic 3, July 12-13, 20203

Font overview

CSSC_1

CSSC_2

CSSC_3
AubertE.-S. Lincke, Coptic OCR: Even better models and improvements on user-friendliness, Digital Coptic 3, July 12-13, 2020

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Criteria for training (and test) data selection••••••several printed text editions per fontinhomogeneous scans
Sahidic and Bohairic dialects (if available)
several layouts (one column vs. two columns)
no normalization, simplification or cleaning
comprehensive character set for each font(lower case, upper case, supralinear strokes, various punctuation marks, footnote
signs and other philological markup etc.)

E.-S. Lincke, Coptic OCR: Even better models and improvements on user-friendliness, Digital Coptic 3, July 12-13, 20202

Best ModelsE.-S. Lincke, Coptic OCR: Even better models and improvements on user-friendliness, Digital Coptic 3, July 12-13, 20202

Best Models
CER:–57%–50%–29%–56%

E.-S. Lincke, Coptic OCR: Even better models and improvements on user-friendliness, Digital Coptic 3, July 12-13, 20202

Best Models
Calamari uses Cross Fold Training and Confidence Voting to improve its predictions
cf. Reul, Springmann, Wick & Puppe (2018: Fig. 1; Table II)

E.-S. Lincke, Coptic OCR: Even better models and improvements on user-friendliness, Digital Coptic 3, July 12-13, 2020

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OCR4all: Workflow overview
cf. Reul et al. (2019)• Project at the University of Würzburg• originally designed for historical (German) prints from the Early Modern Period• can be used for Coptic printed texts too

https://www.uni-wuerzburg.de/en/zpd/ocr4all/
E.-S. Lincke, Coptic OCR: Even better models and improvements on user-friendliness, Digital Coptic 3, July 12-13, 2020

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OCR4all: Workflow overview

https://www.uni-wuerzburg.de/en/zpd/ocr4all/
E.-S. Lincke, Coptic OCR: Even better models and improvements on user-friendliness, Digital Coptic 3, July 12-13, 2020

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OCR4all: Workflow overview
cf. Reul et al. (2019)• Project at the University of Würzburg• originally designed for historical (German) prints from the Early Modern Period• can be used for Coptic printed texts too• Interface that runs in a browser (using Docker) or in a virtual machine (VirtualBox)

https://www.uni-wuerzburg.de/en/zpd/ocr4all/
E.-S. Lincke, Coptic OCR: Even better models and improvements on user-friendliness, Digital Coptic 3, July 12-13, 2020

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OCR4all: Workflow overview

E.-S. Lincke, Coptic OCR: Even better models and improvements on user-friendliness, Digital Coptic 3, July 12-13, 2020

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OCR4all: Model selection

E.-S. Lincke, Coptic OCR: Even better models and improvements on user-friendliness, Digital Coptic 3, July 12-13, 2020

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OCR4all: Recognition (Calamari)Calamari:
Wick et al. (to appear 2020)
E.-S. Lincke, Coptic OCR: Even better models and improvements on user-friendliness, Digital Coptic 3, July 12-13, 2020

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OCR4all: Postcorrection (Larex)

Larex:
Reul et al. (2017)
E.-S. Lincke, Coptic OCR: Even better models and improvements on user-friendliness, Digital Coptic 3, July 12-13, 2020

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OCR4all: Output (xml)

E.-S. Lincke, Coptic OCR: Even better models and improvements on user-friendliness, Digital Coptic 3, July 12-13, 20202

Hopes (Plans?) for the future••a Digital Coptic repositorium
an infrastructure in which OCR4all can be run on a (remote) server – no need for
local installation••

better documentation for Coptic OCR
hands-on workshops (like the one planned for this years’ Coptic Congress …):
offline and onlineE.-S. Lincke, Coptic OCR: Even better models and improvements on user-friendliness, Digital Coptic 3, July 12-13, 20202

Coptic OCR data
Data repository for the Coptic OCR project (“working GitLab repository”)(At the moment, the repository, is accessible without registration. This may,
however, change in the future due to copyright concerns etc. In that case,please, contact us.)
DOI: 21.11101/0000-0007-C9D1-A
https://vcs.etrap.eu/Coptic-OCR/datasets
eslincke@staff.hu-berlin.deE.-S. Lincke, Coptic OCR: Even better models and improvements on user-friendliness, Digital Coptic 3, July 12-13, 20202

Thank you …
… for having contributed to and/or supported Coptic OCR:
Heike Behlmer
Marco Büchler
Kirill Bulert
Camilla Di Biase-Dyson
Frank Feder
Florian Finck
Jürgen Knauth
So Miyagawa
Tobias Paul
Christian Reul
Malte Rosenau
Caroline Sporleder
Uwe Springmann
Ronnie Vuine
E.-S. Lincke, Coptic OCR: Even better models and improvements on user-friendliness, Digital Coptic 3, July 12-13, 20202

References
Bourcellier, Laurent. 2006. Création d’une typographie numérique copte adaptée aux usages éditoriaux, Diplômesupérieur d’arts appliqués, arts et techniques de communication option création typographique, Livretd’accompagnement, Ecole Estienne, Paris.
Lincke, Eliese-Sophia, Kirill Bulert and Marco Büchler. 2019. Optical Character Recognition for Coptic fonts: A multisource approach for scholarly editions, in: DATeCH2019 – Proceedings of the 3rd International Conference on
Digital Access to Textual Cultural Heritage, 87-91.
DOI: 10.1145/3322905.3322931
Reul, Christian, Uwe Springmann, Christoph Wick and Frank Puppe. 2018. Improving OCR Accuracy on Early Printed
Books by Utilizing Cross Fold Training and Voting, in: Proceedings of the 13th IAPR International Workshop on
Document Analysis Systems (DAS), Vienna, 24-27 April 2018, IEEE: 423-428.
DOI: 10.1109/DAS.2018.30
Reul, Christian, Dennis Christ, Alexander Hartelt, Nico Balbach, Maximilian Wehner, Uwe Springmann, ChristophWick, Christine Grundig, Andreas Büttner and Frank Puppe. 2019. OCR4all---An Open-Source Tool Providing a(Semi-)Automatic OCR Workflow for Historical Printings, in: Applied Sciences 9(22), No. 4853.
DOI: 10.3390/app9224853
Reul, Christian, Uwe Springmann and Frank Puppe. 2017. LAREX: A semi-automatic open-source Tool for Layout
Analysis and Region Extraction on Early Printed Books, in: Proceedings of the 2nd International Conference on
Digital Access to Textual Cultural Heritage – DATeCH2017, ACM: 137-142.
DOI: 10.1145/3078081.3078097
Wick, Christoph, Christian Reul and Frank Puppe. to appear (2020). Calamari - A High-Performance Tensorflowbased Deep Learning Package for Optical Character Recognition, in: Digital Humanities Quarterly 14(2).
E.-S. Lincke, Coptic OCR: Even better models and improvements on user-friendliness, Digital Coptic 3, July 12-13, 20202