Ubuntu Wiki

This page is to discuss the selection of a PDF renderer for Ubuntu Touch.

One important part to make printing on mobile devices work is a PDF renderer/rasterizer and in addition, it is also needed for displaying PDF files on the screen. As resources on mobile devices are limited, there should be once only one PDF renderer on the system, for both printing and screen display and the one PDF renderer should not be too resource-hungry.

Candidates are Poppler, which was used as screen displayer on the standard desktop all the time and MuPDF, a lightweight renderer from the upstream developers of Ghostscript, who are experts in printing and color management.

Ghostscript is too resource-consuming, is centered in the PostScript interpreter which we do not need here (all apps are new and so we can let them all send PDF when it comes to printing), and its PDF interpreter is mostly written in PostScript, so Ghostscript is not the right thing for mobile and we will not treat it further here.

Blueprint

Advantages MuPDF:

• Probably more lightweight as it is developed with low resource consumption in mind
• Filling forms and saving the file with the filled form content works, no other free PDF software is capable of this
  • Poppler also supports filling and saving forms.

    • According to bug 1153517 it should be fixed in Poppler 0.22.x (Saucy).

• Written by the printing-oriented Ghostscript developers, so better quality for printing expected
  • Since you say we are sending the PDF file directly to the printer, how does that matter?
    • Not directly to the printer, to the printing system and Poppler or MuPDF will convert the PDF into the printer's language.

Advantages Poppler:

• In use for much longer time than MuPDF, so probably less problems of the "File XXX does not display" kind.
• Upstream maintainer is friendly to Ubuntu (and Canonical employee).
• Better accessibility (screen reading) support.
• Poppler is already in use by the standard desktops in Ubuntu, so for convergence it is easier to also use Poppler in Ubuntu Touch.

Please post your ideas here.