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https://issues.apache.org/jira/browse/PDFBOX-5529?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17620474#comment-17620474
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Michael Klink commented on PDFBOX-5529:
---------------------------------------
Looking at the screen shot it is clear why an extractor would add those spaces,
after all you say yourself:
{quote}Visually it appears to have spaces between words,{quote}
And you only wonder why the spaces are there after observing
{quote}but if we copy the text from Adobe Reader and paste it into a text
editor there is no extra spaces.{quote}
Please be aware that Adobe Acrobat also takes tagging information into account;
if there are *ActualText* information, Acrobat uses them and not heuristics
based on the appearance. PDFBox on the other hand does not use the tagging
information in its text stripper.
Thus, please check whether your example file has such tags or not. The easiest
option would be for you to share the file (or at least a page of it with that
behavior).
> Wrong Text Extraction - Unwanted Extra Spaces in the middle of words
> --------------------------------------------------------------------
>
> Key: PDFBOX-5529
> URL: https://issues.apache.org/jira/browse/PDFBOX-5529
> Project: PDFBox
> Issue Type: Bug
> Components: Text extraction
> Affects Versions: 2.0.0, 2.0.1, 2.0.2, 2.0.3, 2.0.4, 2.0.5, 2.0.6, 2.0.7,
> 2.0.8, 2.0.9, 2.0.10, 2.0.11, 2.0.12, 2.0.13, 2.0.14, 2.0.15, 2.0.16, 2.0.17,
> 2.0.18, 2.0.19, 2.0.20, 2.0.21, 2.0.22, 2.0.23, 2.0.24, 2.0.25, 2.0.26, 2.0.27
> Reporter: Carlos Alfonso Maya
> Priority: Major
> Attachments: image-2022-10-18-15-53-06-512.png,
> image-2022-10-18-16-23-00-123.png, image-2022-10-18-16-26-15-001.png
>
>
> *Overview:*
> We are using PDFBOX as a third party API to extract text from financial PDF
> documents.
> We have been using PDFBox since a long time back, and we have detected a
> problem related to a bad text extraction on PDFs from a Customer.
> Since we worked with Customer Data we cannot shared the PDF besides that are
> signed and we cannot even edit them.
> *Description of the problem:*
> By opening the PDF in Adobe Reader we can see several cases like the
> following screenshot:
> !image-2022-10-18-15-53-06-512.png|width=221,height=211!
> Visually it appears to have spaces between words, but if we copy the text
> from Adobe Reader and paste it into a text editor there is no extra spaces.
> The following is the output that PDFBOX generates at the moment of doing text
> extraction:
> {code:java}
> Da te
> In v oice number
> Ou r r eference
> You r reference
> Con tact person{code}
> (!) *Important note: this behavior is present in all the versions of PDFBox.*
> *Analysis:*
> By downloading the PDFBOX source code 2.0.27 (this was checked as well in
> 2.0.26, 2.0.25 and 2.0.24) and testing/debugging we detected that the method
> _*writePage()* inside *PDFTextStripper.java*_ declared a list of objects:
> {code:java}
> List<LineItem> line = new ArrayList<LineItem>();{code}
> Which subsequently the code add elements into the list:
> {code:java}
> line.add(LineItem.getWordSeparator());
> .
> .
> .
> line.add(new LineItem(position));{code}
>
> And at some point it passes the list as a parameter into the following
> statement:
> {code:java}
> writeLine(normalize(line));{code}
> (!) *The important about this list called "line" is that somehow the
> "LineItem" objects are having NULL values inserted into it, and this values
> are at some point interpreted as "blank spaces" causing the behavior
> described above.*
> Here is an screenshot of how it is showed in the debugger:
> !image-2022-10-18-16-23-00-123.png|width=621,height=195!
> !image-2022-10-18-16-26-15-001.png|width=620,height=431!
>
> We tried to look for a method that manipulates this list and that we can
> override, but all of these methods that modified or access the list are
> protected.
>
> (!) *This is an example of how it displayed in the PDF Debugger:*
> {code:java}
> q
> 94.525 545.32 141 11.2 re
> W*
> n
> BT
> /F3 8.8 Tf
> 1 0 0 1 99.325 547.72 Tm
> 0 g
> 0 G
> [ (D) 22 (a) -131 (t) -109 (e) ] TJ
> ET
> Q
> q
> 94.525 530.9 141 11.225 re
> W*
> n
> BT
> /F3 8.8 Tf
> 1 0 0 1 99.325 533.3 Tm
> 0 G
> [ (I) 26 (n) -135 (v) -229 (o) -5 (i) 20 (ce) -62 ( ) 59 (n) -44 (u)
> 30 (m) -27 (b) -75 (e) 28 (r) ] TJ
> ET
> Q
> q
> 94.525 516.5 141 11.2 re
> W*
> n
> BT
> /F3 8.8 Tf
> 1 0 0 1 99.325 519.7 Tm
> 0 G
> [ (O) -73 (u) -151 (r) -44 ( ) 59 (r) -134 (e) 28 (f) -38 (e) 28 (r)
> -44 (e) 28 (n) -44 (ce) ] TJ
> ET
> Q{code}
>
>
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