Andreas Meier commented on PDFBOX-4141:

Thanks for the info Tilman.

Overriding the characters in writeCharacters will not be the problem.
The main question is if this shall be possible to turn on/off by a switch 
implemented in the master of PDFBox, since Adobe themself do some replacements 
in their text extraction methods. 

Whether changes towards replacing/overriding c1/c0 control codes are 
implemented or not, I checked the Adobe Reader output upon c0 and c1 control 
codes and ended up with the attached list.

Notice that for some reason U+0007 is converted to U+0009 and U+000B to U+000A, 
this might be overlooked. (double-checked this, because I first thought of a 

The file is separated into c0 and c1 codes as well as space (U+0020) and del 

Even if a feature like this will not be implemented by Default the mapping list 
might help some people out there.

> Suppress control characters?
> ----------------------------
>                 Key: PDFBOX-4141
>                 URL: https://issues.apache.org/jira/browse/PDFBOX-4141
>             Project: PDFBox
>          Issue Type: Improvement
>          Components: Parsing
>            Reporter: Andreas Meier
>            Priority: Minor
>         Attachments: Mapping_default_to_adobe.csv, Test_with_MW.pdf, 
> Test_with_MW.txt, Test_with_MW_AdobeReader_export.txt, 
> Test_with_MW_linux.jpg, Test_without_MW.txt
> At the moment pdfbox extracts all types of characters.
> Therefore control characters that occur will also be extracted.
> Unfortunately some of these control characters might deform text.
> For example 'MESSAGE WAITING' (U+0095) [MW]
> I attached some files and a screenshot how text is printed when MESSAGE 
> WAITING is present.
> Should PDFBox handle this type of characters? Maybe suppress them in 
> PDFTextStripper?
> I know that PDFBox works correctly in this case, a feature to turn off or 
> suppress special characters might produce better output than the default 
> Setting unless some control characters are used for any further processing!?
> Feedback appreciated.
> What other programs do:
> a) ignore control characters (Okular PDF Viewer - KDE)
> b) exchange them  (Adobe Reader wrote a dot "." in place of MW)
> Regards
> Andreas

This message was sent by Atlassian JIRA

To unsubscribe, e-mail: dev-unsubscr...@pdfbox.apache.org
For additional commands, e-mail: dev-h...@pdfbox.apache.org

Reply via email to