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https://issues.apache.org/jira/browse/PDFBOX-3804?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Alexandre updated PDFBOX-3804:
------------------------------
Description:
Hi,
To extract text by paragraphs is probably the most looking forward improvement
asked by PDFBox users.
*The current text extraction approach detects correctly end of lines. But it
does not detect correctly end of paragraph.* Indeed, a carriage return
character is added after each end of line.
*What is a paragraph ?* A paragraph is a text that contains one or several
sentences. It can start by a tabulation but this is not mandatory. In a
paragraph, there is one or more lines but there is no carriage return (except
the one at the very end). A paragraph can end before the very end of a line,
but some paragraphs end at the very end. To find paragraphs that ends before is
a reasonable goal.
*So, the last line of a paragraph ends before reaching the very end of the
line.* +And an algorithm could use that pattern to detect properly paragraphs.+
In my opinion, the algorithm never adds carriage return except when a end of
paragraph is detect.
In my opinion, the algorithm should use the following information:
(*) the width of the block containing the paragraph ;
(*) detect the padding and margin of that block ;
(*) precomputed width of the next word.
The width of a block is either the width of the pdf minus left and right
margins if the pdf has one column. Or the width of a block is the width of a
column if the pdf has two columns for example.
The algorithm runs on every character and when it reach the last character of a
line, it pre computes the next line first word to have it's width. If this word
fits in the previous line, then the algorithm concludes an end of paragraph.
Cheers,
A.
was:
Hi,
To extract text by paragraphs is probably the most looking forward improvement
asked by PDFBox users.
*The current text extraction approach detects correctly end of lines. But it
does not detect correctly end of paragraph.* Indeed, a carriage return
character is added after each end of line.
*What is a paragraph ?* A paragraph is a text that contains one or several
sentences. It can start by a tabulation but this is not mandatory. In a
paragraph, there is one or more lines but there is no carriage return (except
the one at the very end). A paragraph can end before the very end of a line,
but some paragraphs end at the very end.
*So, the last line of a paragraph ends before reaching the very end of the
line.* +And an algorithm could use that pattern to detect properly paragraphs.+
In my opinion, the algorithm never adds carriage return except when a end of
paragraph is detect.
In my opinion, the algorithm should use the following information:
(*) the width of the block containing the paragraph ;
(*) detect the padding and margin of that block ;
(*) precomputed width of the next word.
The width of a block is either the width of the pdf minus left and right
margins if the pdf has one column. Or the width of a block is the width of a
column if the pdf has two columns for example.
The algorithm runs on every character and when it reach the last character of a
line, it pre computes the next line first word to have it's width. If this word
fits in the previous line, then the algorithm concludes an end of paragraph.
Cheers,
A.
> Detect end of paragraphs
> ------------------------
>
> Key: PDFBOX-3804
> URL: https://issues.apache.org/jira/browse/PDFBOX-3804
> Project: PDFBox
> Issue Type: Improvement
> Components: Text extraction
> Affects Versions: 2.0.6, 2.0.7, 3.0.0
> Reporter: Alexandre
> Priority: Minor
> Labels: extraction, paragraph
> Attachments: example.pdf
>
>
> Hi,
> To extract text by paragraphs is probably the most looking forward
> improvement asked by PDFBox users.
> *The current text extraction approach detects correctly end of lines. But it
> does not detect correctly end of paragraph.* Indeed, a carriage return
> character is added after each end of line.
> *What is a paragraph ?* A paragraph is a text that contains one or several
> sentences. It can start by a tabulation but this is not mandatory. In a
> paragraph, there is one or more lines but there is no carriage return (except
> the one at the very end). A paragraph can end before the very end of a line,
> but some paragraphs end at the very end. To find paragraphs that ends before
> is a reasonable goal.
> *So, the last line of a paragraph ends before reaching the very end of the
> line.* +And an algorithm could use that pattern to detect properly
> paragraphs.+
> In my opinion, the algorithm never adds carriage return except when a end of
> paragraph is detect.
> In my opinion, the algorithm should use the following information:
> (*) the width of the block containing the paragraph ;
> (*) detect the padding and margin of that block ;
> (*) precomputed width of the next word.
> The width of a block is either the width of the pdf minus left and right
> margins if the pdf has one column. Or the width of a block is the width of a
> column if the pdf has two columns for example.
> The algorithm runs on every character and when it reach the last character of
> a line, it pre computes the next line first word to have it's width. If this
> word fits in the previous line, then the algorithm concludes an end of
> paragraph.
> Cheers,
> A.
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