Processing Illustrator or pdf files into XAML - xaml

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).

Related

How is hidden text stored in OCR-enhanced PDF files

// EDIT 26.03.2018 - Who wants to continue my work can have a look on my source-files https://github.com/n0l0cale/ocr-sampledata
I'm actually looking for some details about PDF Files. It's most important for me that the files will be usable for a very long time and if possible the OCR should be automatically applied for new files (which seems to be not really possible with Adobe Acrobat...).
For that I've been looking for different solutions how to OCR my PDF Files. I found three candidates which seems to be doing what they should do... (more or less). But all three variants have their pro&cons... But there seem to be different approaches how to store data in PDF Files.... for all three Variants... Let me explain:
a File OCRed with Adobe Acrobat:
https://github.com/n0l0cale/ocr-sampledata/blob/master/A4%20sample_ACROBAT.pdf
results in a file that Acrobat is able to open in one step (no preloading of any background layer) and after a preflight-script I'm able to see the text which is stored hidden:
a File OCRed with Abby Finereader:
https://github.com/n0l0cale/ocr-sampledata/blob/master/A4%20sample_ABBY.pdf
does not seem suitable for the default adobe preflight-script as it does not display any additional layers:
But far as I was able to reproduce these Files seems to have a Background-Text-Layer, which contains the OCRed Text, which is the underlying layer for the Image that is shown to the user at the end. Unfortunately this seems to be loaded separately and this is confusing while opening the file with Adobe Acrobat...
a File OCRed with Tesseract 4 (Alpha):
https://github.com/n0l0cale/ocr-sampledata/blob/master/A4%20sample_TESSERACT_oem2.pdf
is also doing some weird magic with the hidden text part:
But in all three cases I'm able to search for words in the files and see the text using "Remove hidden information" and selecting "hidden text":
I'm seriously confused.... Does anyone know how these programs are storing their hidden text information really?
S.
P.S.: For those wondering what this ominous preflight script is: https://theblog.adobe.com/hidden-gems-in-acrobat-dc-how-to-optimize-hidden-ocr-text/
Does anyone know how these programs are storing their hidden text information really?
You correctly have found out that the approach of Abby Finereader is different from that of Adobe Acrobat and of Tesseract:
Abby creates a page content stream in which first the text is drawn normally on the page and eventually covered by the scanned image.
Acrobat and Tesseract create content streams in which first the image is drawn and then the text is drawn invisibly (using text rendering mode 3 which draws nothing).
The difference between the latter two results is the choice of font used:
Acrobat uses regular standard 14 fonts for which a PDF viewer has a font program to render them as normal glyphs.
Tesseract uses a font GlyphLessFont it embeds a font program for into the result file. When rendered the glyphs in this font do not show as our normal Latin glyphs but merely as empty space.
Considering the visual effect you observed for the Abby result, the approach used by Acrobat or Tesseract might be preferable.
Whether one prefers fonts with visually recognizable glyphs (as used by Acrobat) or without (as used by Tesseract), is mostly a mere matter of taste. They are used only in the invisible rendering mode anyways.

Is there any way to prevent losing text when converting a PDF to a PNG when using <CFPDF>?

Using the following code to generate thumbnails from PDFs (ColdFusion 8):
<cfpdf
action="thumbnail"
source="#LOCAL.PathToMyPDF#"
destination="#LOCAL.ImageDestination#"
format="png"
scale="100"
resolution="high"
overwrite="true"
pages="1" />
Sometimes it works great and generates a beautiful PNG representation of the first page. However, many times, it ends up creating a PNG with none of the text that's in the PDF, or with the text mangled or background images out of arrangement.
Is there any way to prevent this? I'm open to using a non-commercial java library, if necessary.
Without looking into this too deep, I would think you are having a font problem.
Try to run that bit of code with this parameter nofonts = "true" (which removes font styling) and see if you get your text (not styled).
If that works then you may need to register your fonts in Coldfusion (so Coldfusion has access to the fonts library). If you are not sure what fonts your PDF uses then you can check file, properties and click the font tab to see the fonts your PDF uses.
Check this link for more explanation on Coldfusion and fonts.
Again, I am not sure about your server and font set up because it wasn't mentioned in your post, so this is my best guess for you...
:)

Enabling select and copy of text content in PDF

What can prevent PDF-1.4 document's content from being selectable and copyable?
I'm generating PDF-1.4 documents using TTF fonts, which are successfully embedded in it (see screenshot below).
Yet I can't select and copy the text from the document. I have studied the PDF-1.4 spec and found only one mention of copy-protecting the document, which has a prerequisite of first encrypting it. And I don't encrypt the document.
So, ideally, I'd like to discover an exhaustive list of reasons, that can prevent the PDF text from being copied, and ways to control that.
There is only one reason, you are embedding your fonts partially. The information you are storing there is the minimum required for drawing the glyphs, but it is not enough for allowing text extraction. For example, in Acrobat Professional, optimizing a file for reducing file size will have this effect, since everything that is not strictly required for presenting the content will be discarded.

A better file format than PDF or EPUB?

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.

PDF Colo(u)r Analysis (without Acrobat itself ?)

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).