pdf2svg | A PDF to SVG converter written using PDF.js | Document Editor library

I'm building a web app to help students with learning Maths.

The app needs to display Maths content that comes from LaTex files. These Latex files render (beautifully) to pdf that I can convert cleanly to svg thanks to pdf2svg.

The (svg or png or whatever image format) image looks something like this:

I'm trying to extract text information from a (digital) PDF by identifying content and location of each character and each word. For words, pdftotext --bbox from xpdf / poppler works quite well, but I cannot find an easy way to extract character location.

What I've tried

The solution I currently have is to convert the pdf to svg (via pdf2svg), and then parse the resulting svg to extract single character (= glyph) locations. In a third step, the resulting boxes are compared, each character is assigned to a word and hopefully the numbers match.

Problems

While the above works for most "basic" fonts, there are two (main) situations where this approach fails:

• In script fonts (or some extreme italic fonts), bounding boxes are way larger than their content; as a result, words overlap significantly, and it can well happen that a character is entirely contained in two words. In this case, the mapping fails, because once I translate to svg I have no information on what character is contained in which glyph.
• In many fonts multiple characters can be ligated, giving rise to a single glyph. In this case, the count of character boxes does not match the number of characters in the word, and matching each letter to a box is again problematic.

The second point (which is the main one for me) has a partial workaround by identifying the common ligatures and (if the counts don't match) splitting the corresponding bounding boxes into multiple pieces; but that cannot always work, because for example "ffi" is sometimes ligated to a single glyph, sometimes in two glyphs "ff" + "i", and sometimes in two glyphs "f" + "fi", depending on the font.

What I would hope

It is my understanding that pdf actually contain glyph information, and not words. If so, all the programs that extract text from pdf (like pdftotext) must first extract and locate the various characters, and then maybe group them into words/lines; so I am a bit surprised that I could not find options to output location for each single character. Converting to svg essentially gives me that, but in that conversion all information about the content (i.e. the mapping glyph-to-character, or glyph-to-characters, if there was a ligature) is lost, because there is no font anymore. And redoing the effort of matching each glyph to a character by looking at the font again feels like rewriting a pdf parser...

I would therefore be very grateful for any idea of how to solve this. The top answer here suggests that this might be doable with TET, but it's a paying option, and replacing my whole infrastructure to handle just one limit case seems a big overkill...

I am using pdf.js to extract text from the pdf but the font name appears as g_d0_f6 etc. I need the font name to use the appropriate table for converting to Unicode. Here is the code derived from pdf2svg.js sample:-

I will be ever so grateful if anyone can provide step by step help to install PGFPlots in windows for usage in Julia.

http://nbviewer.jupyter.org/github/sisl/PGFPlots.jl/blob/master/doc/PGFPlots.ipynb#PGFPlots

The website recommands:

Pdf2svg. This is required by TikzPictures. On Ubuntu, you can get this by running sudo apt-get install pdf2svg and on RHEL/Fedora by running sudo dnf install pdf2svg. On Windows, you can download the binaries from http://www.cityinthesky.co.uk/opensource/pdf2svg/. Be sure to add pdf2svg to your path (and restart).

Nevertheless, not a computer expert I do no understand:

To cross compile for Windows under Linux, simply install the relevant cross-compiler packages (for Fedora this is mingw32-cairo and mingw32-poppler and their dependencies) and then replace “./configure” in the compilation instructions above with “mingw32-configure”.

So if anyone can point me to the right direction that would be great?

In our company we want to come up with universal solution for creating interactive presentations as mobile applications. First idea was to create a PDF file and use it in mobile phone, it didn't work out - it was too slow. Another idea was to convert PDF into SVGs and use them as scenes (slides) and that's what I am working on right now. What I forgot to mention, that PDF contains internal link annotations to navigate between pages.

So, for PDF to SVG conversion I use pdf2svg cli tool. I also wrote PHP cli application to parse all the links from PDF with their position. For conception I use ReactJS to test this idea on the WEB first (I have never worked with React Native before).

Now the problem: PDF contains a lot of high resolution images and a lot of pages, so some of SVG files are very large (up to 11MB) and size of all SVGs is ~70MB. When rendering these large SVG files, there is a delay (~1-10 seconds), comparing to PDF file that's not a huge win, so I need to optimise loading time.

What I have tried so far:

1. With earlier mentioned PHP CLI utility I wrote, I put some data about links inside SVG files (). Then I rendered SVG by containing page number inside state with and on each render created onClick event listeners for tags inside SVG for navigation. Well, it was first try and I wasn't satisfied with performance.

2. I tried to use react-svg-loader to inject SVGs as components. It didn't work out, performance was even worse (well, converting 70MB SVGs to JSX components doesn't sound good). By the way, I tried to build project for production, it tooks so long I just couldn't wait. So, not an option.

3. Instead of SVG, I tried to use PNG images with smaller resolution (each PNG was about 800kb) and put links as div elements on top of an image, performance was really good, but I lost quality. So not an option.

4. Same as 3, but with SVG and . I think it is slightly better, but still not a win.

Do you have any suggestions how could I improve performance by still using SVG? Should it perform better or worse in React Native?

I'm calling a bunch of command-line interface (CLI) tools (such as texi2pdf or pdf2svg from an R script, and I'd like to capture the output file of these tools directly as an R object, without touching the file system.

This is the opposite concern of the more frequent "how-do-I-redirect-stdout-to-file"-question. (Perhaps that implies that I'm "using it wrong").

Example:

Say, I have a simple latex reprex.tex file that I'd like to compile:

I am migrating an application (PDF2SVG at http://github.com/contentmine/pdf2svg) from PDFBox-1.8.8 to PDFBox-2.0.6. In the POM I have