Here is what I need to do:
Merge several PDF documents (which may or may not be PDFA) into one PDFA1b.
Add a watermark (a simple text label) on each page of the resulting PDF.
It has to be with iText 5
I have looked at this official merging example: http://developers.itextpdf.com/examples/merging-pdf-documents/adding-cover-page-existing-pdf
But can this method be used to create a PDFA, and also add watermarks?
Or am I stuck with using this other method which he specifically says not to use: http://developers.itextpdf.com/examples/merging-pdf-documents-itext5/how-not-merge-documents
You can create files that conform to PDF/A-1b with just about any PDF library including iText. PDF/A, in general, is a subset of ISO 32000 (PDF) so it's really just a matter of using the tool to do what you need to with the files but not adding anything that is forbidden by PDF/A-1b (in your case).
The thing to be aware of is that iText or any of the other libraries that "support" PDF/A, will not prevent you from modifying PDF in a way that is forbidden by PDF/A... you just need to know what those things are.
So... before merging, you'll want to be sure that the input files don't have any annotations or form fields or any other interactive content.
After merging, add your watermark as page content and be sure your XMP metadata is conforming and you should be OK.
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.
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.
What are the alternatives to process illustrator files or PDFs into XAML. My Current workflow works like this:
Open the PDF file in Adobe illustrator
Save the file as .ai (Adobe Illustrator) file
Open in Expression Design
Do some processing, mainly separating elements to layers and removing unneeded parts.
Save as XAML
Add XAML to Blend project
My only problem is that this way the text gets converted to paths. I would like to keep my text in XAML as well instead of paths.
Is there any other way to do this, so I keep the text? Any other tools?
I think what you want is to have Glyphs elements instead of Paths.
The problem is that Glyphs elements require you to specify the URI of the font file. Also, Glyphs elements reference glyphs by their index into a font file (it may happen that a converter that generates Glyphs elements - like the Microsoft XPS Document Writer - uses indices into font subset files: so these indices may not be the right indices to the same glyphs as defined in the original font file). I have been able to "solve" this problem in two ways with my own PDF to XAML conversion tools.
1. approach: Embed the font-subset file, BASE64 coded, in the generated XAML code and have the application implement a class that, upon loading, extracts and decodes an embedded font-subset file to a temporary location and hands a valid URI to that temporary file back to the XAML loader.
or, 2. approach: Have most font files already installed along with my application and, again, adding some support by my application that replaces the font name by an URI to the installed font file upon loading of the XAML code. The problem with this second approach is that glyph indices need to be correctly mapped to the installed font file, which may not be all that trivial to do. (You can find a link to an example file that has been generated for this way of loading on my blog: in particular take a peek at the file truncatedcone-xaml.txt)
In short: both solutions require a special PDF to XAML converter and support by the loading application. The reason I wanted to do it this way instead of just having my PDFs converted to Paths only is that my application is a shared whiteboard: thus I want my vector graphics to be as small as possible. (Conversion to paths tends to blow up the XAML code by a factor of 10 or more in most cases).
I am contemplating the implementation of a third approach: this would consist in generating the outline for every glyph that is used only once and then add support by my application to transform and position these glyph outlines in a way closely analogous to what Glyphs elements do that would otherwise have to be generated. The advantage would be that the generated XAML would still be relatively small (comparable to the second approach described above) without requiring the relevant font files to be installed along with the application and without having to map glyph indices from a subset file to the installed font file. The reason I have not yet tried to implement this in earnest is twofold: first, my current (second) approach already works very well for what I currently need; second, there might be performance problems with this third approach as reagards loading and / or rendering.
There's a (free) Adobe Illustrator plugin to export to XAML. Not sure it does exactly what you are looking for, though.
Find it at http://www.mikeswanson.com/XAMLExport/
Well an XPS file is actually a ZIP file. So if you open it with a ZIP-archiver or if you rename its extension to ZIP you can see what is inside. It already contains the pages as XAML code (those files have the form [pagenumber].fpage). However, that XAML code may refer to other files (like raster images and font subset files, those are typically odttf files - basically encrypted true type files) that are included in that ZIP archive as well. Which means, that the XAML code that you find in an XPS document may not be directly usable as pure XAML in your application. I have written python scripts to do the conversion of XAML taken from XPS documents (generated by the Microsoft XPS Document Writer) to get XAML files that my application can load (see approaches 1 and 2 above). I could send you copies of those python scripts (they are not particularly great code, which is no problem for me since I am now using a different approach to convert PDFs to XAML anyway).
#gyurisc: Keeping the font file should work but keeping the text might turn out to be a problem, because, you see, glyphs are not characters. It might be that you could figure out the character by examining the font file that a given glyph is part of, but that would involve parsing the font file. If you are unlucky, your PDF to XPS converter does even not keep enough information in the font subset files to figure out the character a given glyph (very likely) represents.
For example: If I convert a PDF file to XPS with the help of Microsoft's XPS Document Writer, and then try to select a piece of text from that XPS document, I can (only apparently) copy it to the clipboard. However, if I then paste it back into a Word document, I get garbage. Whereas if I select that same piece of text in the original PDF document and paste it into the same Word document, I get reasonably meaningful text. So Microsoft's XPS Document Writer apparently does not care about the interpretation of a "glyph run" as text, and thus it seems very likely to me that the link between the glyph indices that one finds in the generated XPS code and the characters they are meant to represent is already broken at that point. (But, admittedly, that's just a guess.)
A representation of text (as opposed to a run of glyphs) would be a TextBlock element in XAML, I suppose. However, my guess is that a typical PDF to XPS converter is unlikely to generate TextBlock elements. XPS is mainly meant to be rendered - on screen or on paper - it doesn't suggest itself as a file format that is particularly suitable for data exchange (exchange of text in your case).
Is there a library/tool which would list all colours used in a PDF document ?
I'm sure Acrobat itself would do this but I would like an alternative (ideally something that could be scripted).
So the idea is if you have a very simple PDF document with four colours in it the output might say :
RGB(100,0,0)
RGB(105,0,0)
CMYK(0,0,0,1)
CMYK(1,1,1,1)
You could explore the insides with pdfbox, but you would have to write some code to find and catalog all those colors.
Most PDF tools have access to this information but no api to access it. You could take any tool and add it in
Apago PDFspy generates an XML file containing all kinds of metadata extracted from PDF files. It reports color usage including spot colors.
We recently added a function called GetPageColorSpaces(0) to the Quick PDF Library - www.quickpdflibrary.com to retrieve much of the ColorSpace info used in the document.
Here is some sample output.
Resource,\"QuickPDFCS2eb0f578\",Separation,\"HKS 52 E\",DeviceCMYK,0.95,0,0.55,0
Resource,\"QuickPDFCSb7b05308\",Separation,\"Black\",DeviceCMYK,0,0,0,1
Resource,\"QuickPDFCSd9f10810\",Separation,\"Pantone 117 C\",DeviceCMYK,0,0.18,1,0.15
Resource,\"QuickPDFCS9314518c\",Separation,\"All\",DeviceCMYK,0,1,0,0.5
Resource,\"QuickPDFCS333d463d\",Separation,\"noplate\",DeviceCMYK,1,0,0,0
Resource,\"QuickPDFCSb41cafc4\",Separation,\"noprint\",DeviceCMYK,0,1,0,0
Resource,\"Cs10\",DeviceN,Black,Colorant,-1,-1,-1,-1
Resource,\"Cs10\",DeviceN,P1495,Colorant,-1,-1,-1,-1
Resource,\"Cs10\",DeviceN,CalRGB,Colorant,-1,-1,-1,-1
Resource,\"Cs10\",Separation,\"P1495\",DeviceCMYK,0,0.31,0.69,0
XObject,\"R29\",Image,,DeviceRGB,-1,-1,-1,-1
Disclaimer: I work at Atalasoft.
Our product, DotImage with the PDF Reader add-on, can do this. The easiest way is to rasterize the page and then just use any of our image analysis tools to get the colors.
This example shows how to do it if you want to group similar colors -- the deployed example will only work for PNG and JPEG, but if you download the code, it's trivial to include the add-on and get PDF as well (let me know if you need help)
Source here:
http://www.atalasoft.com/cs/blogs/31appsin31days/archive/2008/05/30/color-scheme-generator.aspx
Run it here:
http://www.atalasoft.com/31apps/ColorSchemeGenerator
If you are working with specific and simple PDF documents from a constrained source then you may be able to find the colors by reading through the content stream. However this cannot be a generic solution.
For example PDF documents can contain gradients or transparency. If your document contains this type of construct then you are likely to end up with a wide range of colors rather than a specific set.
Similarly many PDF documents contain bitmapped images. Given that these will need to be interpolated to be displayed at different resolutions, the set of colors in a displayed PDF may be bigger or different to (though obviously broadly similar to) the embedded bitmap.
Similarly many PDF documents contain constructs in multiple color spaces that are rendered into different color spaces. For example a PDF might contain a DeviceRGB bitmap, a line in an ICC based CMYK color and a Lab based rectangle. The displayed version might be in sRGB for display or CMYK for print. Each of these will influence the precise set of colors.
So the only 100% valid answer is going to be related to a particular render of a PDF at a particular resolution to a particular color space. From the resultant bitmap you can determine the colors that have been used.
There are a variety of PDF libraries that will do this type of render including DotImage (referenced in another answer) and ABCpdf .NET (on which I work).