Bug 342504

Summary:	Add possibility to copy formulas as MATHML/Latex Math/OO Math
Product:	[Applications] okular	Reporter:	Christoph Thielecke <crissi99>
Component:	PDF backend	Assignee:	Okular developers <okular-devel>
Status:	REPORTED ---
Severity:	wishlist	CC:	cfeck, yurchor
Priority:	NOR
Version:	0.20.2
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed In:

Description Christoph Thielecke 2015-01-05 12:20:14 UTC

It would be nice if there is a possibility to copy a certain text (which is a formula) as formula (detect and convert) and let return the specfic formula syntax text to clipboard.
Possible target formats should be MATHML, Latex. Another possible candidate is LibreOffice /OpenOffice math.

From user perspective, I expect to select the select function and have addional entries like under "Text": copy as MATHML to clipboard, copy as Latex to clipboard, copy as LibreOffice Math to clipboard

Reproducible: Always

Comment 1 Christoph Feck 2015-01-05 20:17:44 UTC

Is there any other software able to extract formulas from PDF? To me it looks like a very hard problem, as soon as the formulas use multiple levels of text (fractions etc.)

Comment 2 Yuri Chornoivan 2015-01-05 20:36:31 UTC

(In reply to Christoph Feck from comment #1)
> Is there any other software able to extract formulas from PDF? To me it
> looks like a very hard problem, as soon as the formulas use multiple levels
> of text (fractions etc.)

MaxTract (development canceled) can do the extraction directly.

http://www.cs.bham.ac.uk/research/groupings/reasoning/sdag/maxtract.php

Infty Reader can do it using OCR.

Some thoughts on the problem can be found here (my tests confirm the conclusions of this paper and nothing seems changed from 2011):

http://www.cs.bham.ac.uk/~aps/research/papers/pdf/BaSeSoSu-ICDAR11-ComparingApproachesToMathematicalDocumentAnalysisFromPDF.pdf

IMHO, it is hard to expect that free OCR engines like Ocropus/Tesseract can solve the problem in the nearest future. At least, I failed to train Tesseract in recognition of even rather simple formulas.