OCR within an x,y window of a pdf - pdf

I need to find an open source or linux based utility that allows me to set an x,y coordinate in a setup file. I would like to then sequentially open pdf's and look in the documents for first, last name and account number and save the file with a file name consisting of last name and file number.


You may want to read some of these answers first :
A Java Library for text extraction from PDF documents preserving empty spaces and lines
How to extract text from a PDF?
How-to extract text from a pdf doc within a specific rectangular region?
The answers above are not Linux specific.
Most PDF documents do not need to be OCR'ed as the text is contained within the PDF. The hard part is extracting in. The Java version of iText (http://itextpdf.com/) is probably the best toolkit under Linux to extract the PDF text strings. Another option may be http://pdfbox.apache.org/
If the text you need to extract is actually an image then you will probably need to convert the whole PDF page to image format such as TIFF and pass that into an OCR engine such as Google Tesseract OCR.

Related

What's the best way to extract text from pdf in python without changing the layout and format?

I want text with exact format and layout from pdf.
If pdf to text is not the direct choice, is it possible to do pdf -> xml -> text?
I have already tried PyPDF2, pdfminer and pdftotxt. Even I've tried using AWS textract and got incorrect layout.
Basically if I can construct sentence from the text extracted from pdf, that's enough.
I used Zamzar API which gives exact output but they're quiet expensive.
Any possible solution?

If you are looking to keep the structure of the PDF but not the font, colour, size etc., then try the pdftables_api library. This should hold the layout of your PDF. Convert PDF to CSV as a CSV file is just a comma seperated text file.
If you are looking to keep font, colour etc., Zamzar API is probably your best option.

Batch check Adobe Acrobat .pdf's for files containing rotated text

Does anybody know if there is a way to check whether a list of Adobe Acrobat .pdf files contain rotated text (any text not at 0 degrees)?
I thought this would be simple, but I'm struggling to find an answer.
I am using ABBYY Recognition Server to OCR thousands of files and the results are quite poor where the text is rotated. I need to get a list of files that have rotated text to allow me to perform some pre-processing on them.
I usually use iTextSharp for .pdf automation and modification but don't seem to be able to find anything for checking text rotation.
Thanks

You could achieve your goal by extracting all words from these PDFs and checking if any of the words is rotated.
I would recommend you to use a PDF library higher level abilities for the task. Docotic.Pdf library is a good choice (of course, I am one of the developers of the library).
Here is an articles that shows how to extract words from PDFs with extra info about their position etc.
Each extracted word comes in PdfTextData object. The PdfTextData contains IsTransformed property to check if word is rotated, scaled, and / or flipped. You can also analyze PdfTextData.TransformationMatrix for more information about the transformation.

ghostscript extract pages containing a text string

i need to programmatically extract from a multipage pdf, only the pages containing a text string. Is it possible or i need some other tools? I'm working on aix.
thanx in advance

OK firstly Ghostscript doesn't extract pages from PDF files. It creates brand new PDF files whose visual appearance should be the same as the original, but whose content will be different.
There is no way to do this with Ghostscript in a single pass. You could use the txtwrite device to extract the text then grep through the output files for the text you want, note the page numbers and then run another pass to get those pages into new files.
Be aware that extracting text from a PDF file is far from guaranteed to work! That was not the intent of the original PDF format.
Also note that GHostscript currently only allows for handling a single range of pages, First->Last, so if you have a discontinuous set (eg pages 1, 3, 5, 7 etc) then you will have to run this step multiple times.

Apache POI - Word Files

I have been successfully able to read a word document containing images usiong POI.
I have even be able to extract a section from Word document including the images.
I am writing the extracted portion containg images to a new word document.
My problem is that I have to display this extracted portion (containing text, fonts, colors images) on the screen using any standard Java Swing component.
Please advise how can I do that?
I tried JText, Panel, editor but all would take only text and I loose my formatting and images.
Regards

Copy+pasting text from PDF results in garbage

I am writing a Master's thesis - NLP system. I have one component - extractor.
It is extracting a plain text from PDF files. There are a few PDF files that can not be extracted correctly. Extractor (PDFBox library) returns a string like this:
"┤xDn║if|d├gDF"Ti&cD╬lh d FÁhis~n ╗xd f«"d┤ffih »h"
or
"10a61a91a22a25a3a27a17a23a20a8a13a14a61a25a17"
I was checking each file that makes this extraction's problem and all these files' text also can not be copy-pasted from PDF Reader (Adobe Reader and FoxIt reader). Viewing them in this readers is enabled, but after selecting its content and copying to the clipboard I get the same wrong text (as described above - strings of not semantically correct chars or strings of digits and letters).
Could anybody help me???

Very often in such cases, where you can't select, copy'n'paste text from the Acrobat (Reader) window, there is another option which may work nevertheless:
Open 'File' menu,
select 'Save as...',
select 'Text (normal) (*.txt)',
browse to the target directory,
type the name you want to use for the text file.
You'll have all text from all pages in the file and need to locate the spot you wanted to copy'n'paste initially -- insofar it is not as comfortable as direct copy'n'paste. But it works more reliably....
It also works with acroread on Linux (but you have to choose 'Save as text...' from the file menu).
Update
You can use the pdffonts command line utility to get a quick-shot analysis of the fonts used by a PDF.
Here is an example output, which demonstrates where a problem for text extraction will very likely occur. It uses one of these hand-coded PDF files from a GitHub-Repository which was created to provide PDF sample files which are well commented and may easily be opened in a text editor:
$ pdffonts textextract-bad2.pdf
name type encoding emb sub uni object ID
------------------------------- ------------ ----------- --- --- --- ---------
BAAAAA+Helvetica TrueType WinAnsi yes yes yes 12 0
CAAAAA+Helvetica-Bold TrueType WinAnsi yes yes no 13 0
How to interpret this table?
The above PDF file uses two subsetted fonts (as indicated by the BAAAAA+ and CAAAAA+ prefixes to their names, as well as by the yes entries in the sub column), Helvetica and Helvtica-Bold.
Both fonts are of type TrueType.
Both fonts use a WinAnsi encoding (a font encoding maps char identifiers used in the PDF source code to glyphs that should be drawn).
However, only for font /Helvetica there is a /ToUnicode table available inside the PDF (for /Helvetica-Bold there is none), as indicated by the yes/no in the uni-column).
The /ToUnicode table is required to provide a reverse mapping from character identifiers/codes to characters.
A missing /ToUnicode table for a specific font is almost always a sure indicator that text strings using this font cannot be extracted or copied'n'pasted from the PDF. (Even if a /ToUnicode table is there, text extraction may still pose a problem, because this table may be damaged, incorrect or incomplete -- as seen in many real-world PDF files, and as also demonstrated by a few companion files in the above linked GitHub repository.)

If are able to successfully select and copy the text in Adobe Reader -- indicated that the PDF does contain text objects -- but you can't paste the copied text into Notepad without it looking like a bunch of garbage characters, then the problem is probably related to the CMap that the selected text uses.
The PDF specification provides many options for the display of textual content and the related extraction of the text content. A CMap specifies the mapping from character codes to character selectors. The PDF spec outlines some predefined CMaps, but other CMaps can also be embedded.
My guess is that either the CMap for this text is corrupt or that the PDFBox library doesn't support this particular CMap. I suggest trying a different SDK just to see if you get any different results.

When opened as a Gmail attachment in Chrome (the internal PDF browser) copying does copy normal readable characters!
It worked for me when I had this problem and for others as well. I think the Chrome PDF viewer uses the Google Drive OCR automatically... It's like magic!

What was the PDF created with. Some PDFs do not contain any encoding information, just the data to draw it. So there is no way to extract the data.

Select the text you wish to copy.
Right click
Choose option "Export Selection as"
In the dialog box, choose a file name and save the new file as Rich Text Format (RTF)
Open RTF to see your text!

The best way to deal with this is Convert PDF file to Word by using this website.
https://www.ilovepdf.com/pdf_to_word
The garbage issue will be fixed

The best way to deal with this is (assuming you have Adobe Acrobat, or something similar, not sure if Reader can do this) is save the doc as a JPEG. Then recompile all the images as a single pdf, then use the OCR function to find text in the pages, then you can copy and paste the text.

PDF is not a text document. It's more of a vector graphic format that sometimes can contain text. So there are some documents from which you can't extract text unless you are willing to do OCR. That's just the way it is.