I want to generate a LaTeX document from Objective-C and compile it with pdfLatex so that I have an PDF in the end.
Is there a SDK to do this, or do I need to write to file some LaTeX code from a NSString and run pdflatex with a NSTask ?
Some work has been done on calling out to TeX. There's the TeX daemon, which is part of PyTeX, and which looks like it's doing something like what you need. I've seen this system working, but haven't used it myself and I'm not sure of its current status.
If, on the other hand, you're after doing this programmatically in order to get equation bitmaps (or something like that, which your question vaguely suggests), then you might be interested in the dvipng or dvi2bitmap libraries, which skip postscript/PDF entirely.
As a general point, when doing things like this in the past, I've found it useful to arrange that the LaTeX I generate is pretty high-level, and the detailed layout is deferred to a class or style that you write yourself. That means that you can tune the details of the LaTeX layout while mentally in a LaTeX mode, which ends up less confusing in the end.
Related
We want to keep track of changes in a LaTeX document in such a way that people who can't read LaTeX can also see the changes at once. The .tex files are stored in a git repository. So detailed information about the changes is available.
For this purpose I think it might be possible to use the git diff output between two revisions to generate the PDF and somehow mark the changes since the selected other revision of the document.
Do you know of an (easy) way to achieve this?
Do you know of other ways to visualize differences between PDF files?
[Expanding on my comment, since it apparently helped :-) ]
latexdiff is a Perl script that can diff two LaTeX documents and mark up changes without the distractions of the LaTeX markup itself. The README says:
latexdiff is a Perl script, which compares two latex files and marks
up significant differences between them (i.e. a diff for latex files).
Various options are available for visual markup using standard latex
packages such as "color.sty". Changes not directly affecting visible
text, for example in formatting commands, are still marked in
the latex source. Note that only files conforming to latex syntax will
be processed correctly, not generic TeX files. Some further
minor restrictions apply, see documentation.
A rudimentary revision facilility is provided by another Perl script,
latexrevise, which accepts or rejects all changes. Manual
editing of the difference file can be used to override this default
behaviour and accept or reject selected changes only.
The author is F Tilmann.
The project is developed on Github, but you can get the script in a tarball from CTAN if you prefer. The link in the comment is a useful overview of how to use it.
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.
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 can I open a PDF file and read some of it's contents with Python (this language is preferred, however Ruby, Perl or PHP are fine too) (in case it is recognized (not just an image)) or report that it's impossible without OCR? TIA
Update: thanks for the solutions, I'm sure some of them will suit me fine.
#RichH, I have a pdf file, and don't know whether it is image- or text-based. I'm looking for a tool to help me find that out and in case it's text-based extract some of it's contents.
For Perl, check out these modules:
PDF::API2
CAM::PDF
Parsing PDF and making something useful out of it is hard as the format is focused on keeping the layout so text can be stored in a way that each letter is positioned individually, depending on the font the text might also be stored as graphic.
libraries to read PDFs I know include the Zend Framework which has a PDF component which includes a PDF parser which can be used from PHP and gives more or less usaable results and the commercial PDFlib which offers quite usable results and offers binding to different languages.
Not sure this is a programming question, but we use LaTeX for all our API documentation and user documentation, so I hope it will go through.
Can someone please explain what are the relative merits of using pdflatex as opposed to the "classic" technique of
latex foo
dvips -Ppdf foo
ps2pdf foo.ps
From time to time I run into people who have difficulty because things don't work in pdflatex, and I know that using pdflatex gives up two things I have grown to value:
Can't use the very speedy xdvi viewer
Can't use the PStricks package
I should add that I typically get PDF with hyperlinks by using something on the order of
\usepackage[ps2pdf,colorlinks=true]{hyperref}
so it's not necessary to use pdflatex to get good PDF.
So
What are the advantages of pdflatex that I don't know about?
What are the disadvantages of the old tools that I've overlooked?
My favorite pdflatex feature is the microtype package, which is available only when using pdflatex to go directly to PDF, and really produces stunning results with no effort on my part. Apart from that, the only caveats I run into are image formats:
pdflatex supports PDF, PNG, and JPG images.
the postscript drivers support (at least) EPS.
Also, if you want to install fonts, the procedures are slightly different depending on what fonts that driver supports. (Hint: use XeTeX to instantly enable OpenType fonts.)
As it turns out, I recently read a post that shows the difference directly. Any document that uses tables or narrow columns will be improved automatically. I also find the inter-word spacing to be far more pleasing with pdflatex.
Is xdvi much faster than xpdf? I find the edit, TeX, view cycle to be very quick with pdflatex.
Have you tried MetaPost or MetaFun for graphics? I tend to put graphics creation in the hands of the capable, but MetaFun would likely be the package I'd use. Just reading the manuals is a pleasure.
Also pdftex is the engine under development (towards luatex) and maintenance. I'm not sure the DVI counterparts are as actively maintained.
PStricks is supplanted by Tikz.
I didn't use xdvi in years, so pardon the trollish rhetorical questions: Does xdvi display vector fonts? Does it support synctex (jumping to and from code)? Does it have the confort of use of PDF readers like Skim?
Taco Hoekwater is working on Escrito, a Postscript interpreter written in Lua, which would allow you to use pstricks in Luatex. He has an impressive project completion record: maybe I should have used "will" rather than "would" in the previous sentence.
I used pdflatex to generate the PDF for my ICFP 2009 paper. (I still needed to use standard latex to generate the PostScript file.) I did so for two reasons:
I couldn't seem to get ps2pdf to generate Letter, rather than A4 output, no matter what command line options I used.
For the printers, I needed to produce a version 1.3 PDF file, not 1.4. pdflatex made this easy to do. I set the PDF author and title information while I was at it.
Both of these problems may be fixable in some way, but as a first-time latex user, I didn't find any obvious solutions, nor did more experienced users whom I'd asked.