Scraping PDF to something friendlier - pdf

I've got several documents in PDF form that are almost exclusively transcripts. I'm looking for a way to search through these transcripts (and automate it) and essentially scrape the conversations/headers/etc. to raw data (things like "How many times did X say Y?")
Is there a way that I can convert PDF to a friendlier format (say, HTML or pseudo-HTML) where I can see exactly what's going on?
I'm currently using a scraper that will convert all of the included text into a txt file, which is useful, except that it throws out formatting (bolded statements, etc.) which would make life a lot easier.
Any way to look through PDFs in such a way with Python would be appreciated as well.

You can have a look at our open source library PDF2JSON. It converts all text data to JSON or XML so that you easier can inspect it
http://code.google.com/p/pdf2json

Related

Replace words/phrases in existing PDF or docx with other words

I am trying to make a dynamic PDF generator as an .NET Core API. I want to take an existing PDF, or .docx file, and edit it so it replaces the current name (John Doe) with something that can be replaced like #NAME_PLACEHOLDER.
I then want to transform #NAME_PLACEHOLDER -> John Doe (or whatever is in the KeyValuePair or Dictionary<string, string>).
I am running this on a Docker environment, so I can easily execute commands and I am willing to do that as well.
So far I have tried a few things:
1) pdf2htmlEX
Executes as pdf2htmlEX file.pdf
Does the job pretty well
Can be converted back to PDF using Google Chrome headless or similar
Problem: Only the characters used in the PDF can be used to replace. So if I only use A, B, C as characters, it will make D into Times New Roman (or default font)
2) LibreOffice ODT to PDF
This was pretty nice, because I could simply unzip the .odt file, open content.xml, search and replace, then save it as an .odt file again
Could be converted into PDF rather easily using soffice --convert-to pdf
LibreOffice is quite nice
Problem 1: Microsoft Word -> Save as ODT tends to break the formatting, so we have to use LibreOffice to go and change it back again
Problem 2: We don't want to move away from Microsoft's Office suite
3) HTML to PDF using Chrome Headless
What you see is what you get
By far the best option, if we're all developers aaand have unlimited time
Problem 1: Only our developers can make changes, since our marketing department do not know HTML
Problem 2: Our existing PDFs would have to be rewritten in HTML
As you can see, I have tried a bunch of things. None of them, except Chrome Headless, has lived up to my expectations. What I really like about #3 is what you see is what you get. I can make the whole thing in HTML, press CTRL+P and see what it looks like as a finished PDF, basically.
I am looking for a better solution, though. It can be paid. It can be free. All I need is to change out words/phrases with other words dynamically, which apparently seems like a tough thing to do.
Thanks for specifying what you've already found clearly. It helps a lot providing a succinct answer.
The conversion is always tricky - I'm sure you know Word has trouble displaying/editing some Word documents itself.
I have experience regarding point #2 "LibreOffice ODT to PDF" and can suggest a few things to test:
Don't use Microsoft to do the docx->odt conversion. It's not good as you know. Use LibreOffice itself to do this step. The rest of your process remains the same.
For some documents, Libre Office does doc->odt much better. So, you can instead work with DOC format and get a better result without any other changes.
You won't be able to remove the devs from the process, but you can certainly reduce their role allowing your business/marketing teams to have more direct input simply by:
get the starting point document to the devs to run through the conversion process. The devs can "clean up" the document to make it convert nicely.
make this version of the document the "official" starting point. The business or technical teams can load it, adjust it, and put it back into the process.
if possible, expose a test-platform to the business teams so they can download, adjust, upload and render to PDF. This cycle means they will be able to achieve more and if they're good, do impressive stuff without any dev input.
the above steps simply mean don't expect perfect conversion of arbitrary complex documents. Starting from a (even complex) working baseline is great.
Some of that might show you that your #2 is actually going to get the best overall results.
I hope that helps.

Rule based PDF text extraction for verious bills and invoices

I have to extract text from invoices and bills pdf files
The files layouts can get complex, though its mostly filled with tables.
I've read a few dozens articles already about the pdf format, how easy it is for our brain to grasp it and how hard it is for a machine to understand its structure.
Also downloaded a few tools like the python's pdfminer and some java tools, some even have rule based layout extraction, like LA-PDBtext these are all great libraries, leaving you the final step.
Adobe also has an online service called exportPdf but it can't be customized
Bottom line, I understand that in order to extract text from structured pdf files and convert it to XML for example, there should be some level of manual work.
I also found From Data Extractor, a non free tool with the ability to set extraction rules that claims to do the job, though its hard to find a proper manual and it runs only on windows.
I thought I may even try a to convert those files to images and try tesseract-ocr but decided to ask for advice here before I spend more time on it.
I'll be very grateful if someone with such experience give me a hint.
I've done a lot of PDF extraction and I can confirm as you've already discovered that it can be a painful process to start. One of the important things to understand is that there is no concept of "tables" within a PDF, just text that happens to have lines around it. Also, there's no guarantee that the linear order of text within the PDF code actually matches the visual order when printed. In other words, there's no guarantee that "hello world" is written in that order, it could be draw 'word' at coord 20 then draw 'hello' at coord 10. Most PDF creators don't do this but still there's no guarantee. The more creative a PDF creator is (InDesign, Illustrator, etc) the more likely the text is going to be harder to get out. And actually, once a designer starts messing with fonts too much some programs will sometimes actually output words one character at a time, changing the font just slightly each time.
That said, I'd recommend the first one that you looked at, LA-PDFText. You can run it in discovery mode (blockify) from which you can create rules. I don't have Java installed anymore so I can't test it but it seems very promising.
Your second one, A-PDF Form Data Extractor, only really works with actual PDF forms. If this is your case I'd recommend just using an open source solution like iText/iTextSharp.
The last OCR one makes me cringe. I just can't imagine going through those hoops would get you better text representation than parsing the PDF. But then again, PDF is a visual format so maybe it would.
Personally I use iText/iTextSharp for this kind of thing but I also like to do things the hard way.
It is not clear if you are looking for the development tool to automate the data extraction from bills and invoices or just for the one time tool (utility) that can be used by the non-developer?
Anyway here are some specialized tools including engines they use:
Tabula (open-source, especially designed to extract data from tables in PDF. Can export shell scripts for batch processing, runs as the localhost web service, powered by JRuby Tabula engine)
Viet OCR (open-source .NET desktop utility for text extraction from PDF and images, based on tesseract oct engine)
Bytescout PDF Viewer (freeware closed source .NET utility, detects and extracts tables, including scanned invoices, powered by PDF Extractor SDK)
DISCLAIMER: I work for ByteScout.

writing text to a pdf file

I have several pdf files (about 20) and very month or so I need to change spme fields with new data. This is a very time consuming task and would like to know if there is an easy way via some sort of application where users can change the name of the variables that have to be stored into the different pdf files. This would be an enormous time saver. thanks for any help.
there are lots of solutions for this.. if you are willing to write some code things can get really interesting.
a simple solution would be to create a template pdf file with placeholder fields (like #{name}, #{age} etc.,), when a new pdf needs to be created using new values you can simple use itest to edit the pdf & replace the placeholders with actual values.
you can also use jasperreports for this but it would be an overkill for just 20 odd documents.
if you are interested in a sample program i'd be happy to provide you one.
If you have form fields in the PDF file then you may use Aspose.Pdf (.NET or Java version) to fill data into those fields programmatically. You can either fill the fields using individual values or import the data from the XML/FDF/XFDF files etc. You can take a template PDF and save the output PDF files with different values. Please see if this might help in your scenario.
Disclosure: I work as developer evangelist at Aspose.

Creating ODT and PDF files as end result

I've been working on an app to create various document formats for a while now, and I've had limited success.
Ideally, I'd like to dynamically create a fairly simple ODT/PDF/DOC file. I've been focusing my efforts on ODT, because it is editable, and open enough that there are several tools which will convert it to any of the other formats I need.
The problem is that the ODT XML files are NOT simple, and there aren't any good-quality API's I could find (especially in python). So far, I've had the most success creating a template ODT file, and then manipulating the DOM in python as needed. This is ok generally, but is quickly becoming inadequate and requires too much tweaking every single time I need to alter one of the templates.
The requirements are:
1) Produce a simple document that will have lists, paragraphs, and the ability to draw simple graphics on the page (boxes, circles, etc...)
2) The ability to specify page size, and the different formats should generally print the exact same output when sent to a printer
My questions:
1) Are there any other ways I can produce ODT/PDF/DOC files?
2) Would LaTeX be acceptable? I've never really used it, does anyone have experience converting LaTeX files into other formats?
3) Would it be possible to use HTML? There are a lot of converters online. Technically you can specify dimensions in mm/cm, etc..., but I am worried that the printed output will differ between browsers/converters....
Any other ideas?
have you tried pandoc? i've been using it with good success for the conversion of different formats into each other. why try to invent the wheel twice?
I suppose to be successful, you'd have to define how you want to input everything. Why don't you just use openoffice? it will save to ODT (duh...), PDF, and HTML (though it's not clean HTML, it's actually quite ugly).
In my recent experience, I've had success going from latex -> xhtml via LaTeXML (i had to compile from source). LaTeX is seeming more and more like a terminal format. It's great for PDF, but once you need some flexibility, it kind of fails. I should also note that there is no latex -> dvi in my workflow, so I can't comment on things like tex4ht that reads out of a dvi file (I have too many graphics that don't work with DVI to switch them now).
Shortly I'll be moving everything into docbook 4.5-- i like the docbook-utils package which supports latex, html, and i even saw a converter to ODT. But docbook is super-heavy on the markup, which is annoying, but it will provide me with the flexibility i need going forward.
Since you're using python, have you just considered using ReStructured Text?
I've also really enjoyed publishing from emacs' orgmode, which is a super light weight markup that goes into a bunch of different formats.

How to extract data from a PDF file while keeping track of its structure?

My objective is to extract the text and images from a PDF file while parsing its structure. The scope for parsing the structure is not exhaustive; I only need to be able to identify headings and paragraphs.
I have tried a few of different things, but I did not get very far in any of them:
Convert PDF to text. It does not work for me as I lose images and the structure of the document.
Convert PDF to HTML. I found a few tools that helped me with this, and the best one so far is pdftohtml. The tool is really good presentation wise, but I haven't been able to successfully parse the HTML.
Convert PDF to XML. Same as above.
Anyone has any suggestions on how to tackle this problem?
There is essentially not an easy cut-and-paste solution because PDF isn't really very interested in structure. There are many other answers on this site that will tell you things in much more detail, but this one should give you the main points:
If identifying text structure in PDF documents is so difficult, how do PDF readers do it so well?
If you want to do this in PDF itself (where you would have the majority of control over the process), you'll have to loop over all text on pages and identify headers by looking at their text properties (fonts used, size relative to the other text on the page, etc...).
On top of that you'll also have to identify paragraphs by looking at the positioning of text fragments, white space on the page, closeness of certain letters, words and lines... PDF by itself doesn't even have a concept for a "word", let alone "lines" or "paragraphs".
To complicate things even more, the way text is drawn on the page (and thus the order in which it appears in the PDF file itself) doesn't even have to be the proper reading order (or what us humans would consider to be proper reading order).
PDF parsing for headers and its sub contents are really very difficult (It doesn't mean its impossible ) as PDF comes in various formats. But I recently encountered with tool named GROBID which can helps in this scenario. I know it's not perfect but if we provide proper training it can accomplish our goals.
Grobid available as a opensource on github.
https://github.com/kermitt2/grobid
You may do use the following approach like this with iTextSharp or other open source libraries:
Read PDF file with with iTextSharp or similar open source tools and collect all text objects into an array (or convert PDF to HTML using the tool like pdftohtml and then parse HTML)
Sort all text objects by coordinates so you will have them all together
Then iterate through objects and check the distance between them to see if 2 or more objects can be merged into one paragraph or not
Or you may use the commercial tool like ByteScout PDF Extractor SDK that is capable of doing exactly this:
extract text and images along with analyzing the layout of the text
XML or CSV where text objects are merged or splitted into paragraphs inside a virtual layout grid
access objects via special API that makes it possible to address each object via its "virtual" row and column index disregarding how it is stored inside the original PDF.
Disclaimer: I am affiliated with ByteScout
PDF files can be parsed with tabula-py, or tabula-java.
I made a full tutorial on how to use tabula-py on this article. You can tabula in a web-browser too as long as you have installed Java.
Unless its is Marked Content, PDF does not have a structure.... You have to 'guess' it which is what the various tools are doing. There is a good blog post explaining the issues at http://blog.idrsolutions.com/2010/09/the-easy-way-to-discover-if-a-pdf-file-contains-structured-content/
As mentioned in the answers above, PDF's aren't very easy to parse. However, if you have certain additional information regarding the text that you want to parse, you can pull it off.
If your headings are positioned at specific parts of the page, you can parse the PDF file and sort the parsed output by coordinates.
If you have prior knowledge of the spacing between headings and paragraphs, you could also leverage this information to parse the file.
PDFBox is a PDF parsing tool that you can use for extracting text and images on top of which you can define your custom rules for parsing.
However, for parsing PDFs you need to have some prior knowledge of the general format of the PDF file. You can check out the following blogpost Document parsing for more information regarding document parsing.
Disclaimer:I was involved in writing the blogpost.
iText api:
PdfReader pr=new PdfReader("C:\test.pdf");
References:
PDFReader