I am trying to make an iOS app which would extract plain text from a pdf file and display it in a UITextView. Its simply not a pdf reader to view a pdf file but i would later wish to perform certain operations on that text.
I have already googled a lot but still not able to get an exact solution.
i already tried using https://github.com/zachron/pdfiphone
but the files are using ARMV6 architecture which seems obsolete with xcode 4.5
And if anyone can suggest some exact and non-confusing code using Quartz-2d framework of iOS then it would be great.
Here is An Sample code to Extract text from PDF Hope this Might Help You.
https://github.com/zachron/pdfiphone
This is a library to get the text out of a PDF for the iPhone.
Another Demo is there Which uses OCR technology find the link below
https://github.com/nolanbrown/Tesseract-iPhone-Demo
Also Check this page of the Quartz 2D Programming Guide, it covers everything you need to open and parse a PDF file in iOS. Note that it is not a simple task, since there's no method to extract the full text in one line. You have to work with the data as an input stream, using a CGPDFScanner
Two Other Libraries
https://github.com/KurtCode/PDFKitten/
https://github.com/mobfarm/FastPdfKit
This question comes up all the time. It is VERY hard to extract text from PDF in general. The PDF specification is not designed with text extraction in mind. There are many libraries that try to do the job, essentially by reconstructing the text from the geometric placement of the individual glyphs. These libraries have varying degrees of success, but will all fail on certain PDF documents. In fact, some PDF documents have Glyphs but no way to associate the glyph with a character. For these documents it is simply not possible to extract text, short of using some kind of OCR approach.
PDF is designed as a read-only format that is portable in the sense that a PDF document will be rendered identically on any platform. That is what it is best at, and what it should be used for.
If text is to be edited, do not use PDF.
Here (Extracting text from pdf using objective-c), I found an answer to your question and it works. But not so fine as i need it :(
it can extract only ascii
it return me only one paragraph
Good luck.
Related
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.
I'm trying to use pdf content (mathematics) in my webpage. I basically want to convert the pdf to some vector image. Converting the pdf to swf does the job very well, but as flash isn't supported on every platform, I'm trying to find another solution.
I read about svg, but as those pdf's contain a lot of mathematics, the result of the converters I found is really ugly and incorrect.
I've also thought about retyping the latex, and displaying it using mathjax, in some way this is the best solution, but also very time consuming.
The only thing I want is to convert it to a nice vector image, I don't want to change the content, or anything else. Besides converting to swf or retyping it, is there any other solution ?
Edit:
this is svg output
and here original pdf
The only solution I could find is illustrator.
Just open the pdf, save as svg, and choose to embed all used glyphs.
Result is perfect:
https://dl.dropboxusercontent.com/u/58922976/Sol-10.1.svg
what about using flash + raster image in case of platform without flash, if flash mostly works for you?
Your PDF is a little difficult for reasons that are probably not apparent to you.
The core problem with it is that some of the graphics in the document are actually drawn using custom glyphs. You can see this if you copy and paste the text out of Acrobat. There are a variety of unusual characters in there that don't seem to serve any useful purpose. That's those squares at the bottom of your SVG with EEs and FFs in them.
However these characters are actually custom glyphs for things like the braces around the matrices at the bottom of the page. So they are both fairly important and also very specific to this document.
I tried ABCpdf .NET to convert your PDF to SVG. It worked fine apart from these custom glyphs at the bottom. The output was about 90KB. It looked very similar to your inkscape SVG output but just a bit smaller (the inkscape one is 160KB).
The only way to get rid of these non-Unicode glyphs is to vectorize the text. I did this using ABCpdf and the output looked fine in SVG. But... vectorized text is big and SVG isn't a particularly efficient medium. The output was about 1MB! Zipped it goes down to half that but it's still no-where near as efficient as the original PDF.
The problems I am seeing here are going to be universal whatever format you use. These custom characters are always going to be problematic whether you output to SVG, SWF, HTML canvas, VML or indeed any vector format.
So what would I suggest? Well the obvious vector format that is widely used on the web is... PDF!
I know it's not quite what you're looking for but I think this is the realistic solution given the constraints above. :-)
I'm working on a tool in Python to extract highlighted passages from PDF files. I regularly highlight PDFs in Preview on OS X Lion but haven't found a good tool to extract these passages. Other apps exist that do allow you to highlight and export such as Skim but I figure there has to be a way to extract the ones I add in Preview.
I figured that the highlights would be stored in the HFS+ extended attributes for the PDF file but after looking at them using xattr it seems that they're stored elsewhere. I also looked at PDFKit but I only saw how to create annotations rather than locate them.
If someone could tell me where to find the highlights/annotations or point me at some documentation that explains this I would really appreciate it.
When using PDFKit you can get annotation from any PDFPage instance.
[myPDFPage annotations] will return an array of annotations for that particular page.
See the docs for more info.
Technically speaking, highlighting parts of a PDF is adding an annotation to the file. These annotations are PDF objects defined in the PDF specification. They are stored inside the PDF file itself, i.e. they do modify the original file! That's why you'll not find a trace of the highlights in the HFS+ extended attributes...
So the answer to the question of your title line is: Preview stores the highlights inside the PDF file as fully compliant PDF objects.
The answer to your real question implied in your text ('I want to extract the highlighted passages') was well answered by sosborn.
I am looking to create and save either a rtf, doc or docx file on an iPad (iOS).
The scenario is that we'd like to assist a user in creating content on their iPad and then let them email this as an editable document cross-platform (OS X, WIN).
I am open to other solutions besides the rtf, doc or docx file format.
Thanks,
James
RTF is going to be the easiest, because it's a plain text format. It's kind of like HTML, but without closing tags. Here is a class for writing an RTF, but it requires a lot of dependencies from elsewhere in the framework.
DOCX would be rather difficult. It's actually a zip file, containing a few XML files. You can examine the format yourself by changing the .docx extension to .zip and unzipping it. But even though XML is a fairly easy to write format, the way the text attributes are organized is still rather complicated. Also, I recall that it has to be zipped in a very specific way to be read properly.
As for DOC, it will be very difficult because it's such a complex format. You could look into some open source projects, like Abiword or Word2x. Be careful using their code because the licenses may not agree with the App Store rules.
I've seen doc & docx readers for iPhone (App store entry linked here), but I don't know of any open source frameworks you can make use of.
RTF format should be pretty simple to write, if you're up to the challenge. There is no built in framework support for it (here's a related question, b.t.w.).
Maybe you could write out something in a regular TEXT format and e-mail that?
Docmosis has a cloud service that you can reach from iOS. You can ask it to render a doc in various formats (doc, rtf, pdf, odt etc) and email it off or stream it back - though you have to be connected. Previewing DOC on iOS is possible but a little flaky. One option is to stream PDF back for display on iOS and email editable document (which can be done in one call).
My client wants us to build a custom document viewer for their app. (It really, truly needs to be custom, because there are a ton of application-specific features they need.)
We built one for them last year that took PDFs, generated page images, and backed the images using a hidden layer of text that could be selected and copied. We did it in Flex. It was a nightmare. PDF is horrid.
This year, we need to build one in HTML 5 with similar requirements, except that most of the documents now are in Word or HTML, that is, they have reflowable text, instead of the fixed layout and glyphs of PDF. But they still want to do PDF in the same viewer.
I'm thinking that we need to convert all documents to some common file format that can handle both reflowable text and also the fixed-position glyphs of PDF. (Each document would probably support one or the other, but not both). It would be nice if it were an XML-like markup language that would say:
<text>here's some text</text>
-- or --
<glyph letter="a" name="my_a_glyph" position="10,10"/>
<image src="my_image" position="20,20"/>
or something like that.
Is there any existing file format out there that can handle it? EPUB won't do the fixed-position text, and PDF sucks in too many ways to describe.
I think you can look at FB2 (FictionBook 2) format . That is an XML-based format, designed for publishing books. It includes images, though I am not sure if they can be aligned absolutely.
Also, you can simply go with HTML and do HTML-to-PDF rendering when needed (there exists various components and libraries for this). I don't see (or you have not listed) any reasons why this way doesn't work.
GROFF? Maybe build a macro library to customize it, as needed.
Groff/troff/nroff, the "run off" programs of Unix, can output to postscript or HTML. The jump from postscript to PDF is built in to some PDF viewers; there are also several existing programs for it, pstopdf, for example.
GROFF has some fixed layout options and some flow-like options. With GROFF, it's almost easier to base most of the printout on flowing text, within proscribed bounds.