GSoC 2008 UniConvertor and GraphicsMagick integration

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Revision as of 21:19, 28 March 2008 by Herm (talk | contribs) (Typos)
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Scribus is a serious DTP application and therefore has to deal with many
different fileformats. While it already supports quite a few formats many
others are still lacking or incompletely supported. UniConverter which is
"a universal vector graphics translator"[1] can help for vector formats
and GraphicsMagick which is a branch of the famous ImageMagick does the
same for raster formats[2].

My motivation for doing this project is that I think it will be a huge benefit
for Scribus and I like this kind of work (gluing two programs together). I did
this last year with LaTeX and from the feedback I received it was a great
success. So I want to do something similar this year and hope it will be as 
good or even better than last time.

I'll write an import/export filter that uses UniConverter and GraphicsMagick to
read and write all the formats supported by these programs.


** UniConverter **

* Previous experience
I've not worked with UniConverter before, so this information is based on
a short research only and the implementation details are likely to change.

* Implementation
The import plugin will either call UniConverter directly and get "raw" commands
to create the vector objects or it will use UniConverter to convert to an
intermediate format such as SVG and then read this format.
The same applies to the export filter, but here it might be possible that some 
of the feature supported by Scribus are not supported by the output format and
so the user has to get a message.

* Existing work
The SVG plugin can serve as a base for the new import plugin.

* Userinterface
The list in File->Import gets pretty long, so it might be good to merge these
entries to a better interface, perhaps with autodetection of the fileformat and
manual override.

** GraphicsMagick **

* Previous experience
I have used ImageMagick, the base of GraphicsMagick a lot. I customized the
bash script based dvd-menu-tool dvdwizard[3] at a time when it was less powerful
than today. I had to rewrite a lot of the graphics code which relies on 
I've also a bit of experience with imageframe loaders, because I came across 
this part of Scribus' code when working on my LaTeX frames project.

* Implementation
As GraphicsMagick deals with raster graphics an import filter for image frames
is required here. With libgraphicsmagic++, a C++ library for the GraphicsMagick 
functions, the integration should be pretty easy.

* Existing work
The QT image file loaders can serve as a base.

* Userinterface
No new userinterface is required, but a way to show previews for the new
filetypes has to be found.

** Other changes **

* Build system
The build system has to be updated to look for UniConverter and GraphicsMagick.

Benefits to Scribus
By using these libraries it is no longer necessary to write a new filter for
each new fileformat, but we can profit from the formats added to shared
libraries. For example Inkscape[4] also uses UniConverter starting with version
0.46 [5]. So new fileformat should be usable faster.

Use cases
Importing all kinds of vector and raster formats.

- Import plugin for UniConverter
- Export plugin for UniConverter
- Import only plugin for GraphicsMagick (or integrated into the main code)
- Better structured "File->Import" menu if found to be required
- Documentation


* April 14: Accepted student proposals announced on the Google Summer of Code 
  home page. Community Bonding Period: Students get to know mentors, 
  read documentation, get up to speed to begin working on their projects.

 I can start coding at this point, as I am already familiar with the scribus
 development process.

* May 26: Students begin coding for their GSoC projects;

 At this point I should have read the required documentation and probably the 
 basic functionality for UniConverter ready.

* July 7: Mentors and students can begin submitting mid-term evaluations.

 UniConverter should be fully working now and work on GraphicsMagick is started
 or about to be started.

* July 20: End of semester

 Around this time there will be some exams at university, so expect me to be
 learing a bit more and coding a bit less. No exact dates are available yet.

* August 11: Suggested 'pencils down' date. Take a week to scrub code, write
  tests, improve documentation, etc.
  Now the GraphicsMagick part should be completed too. The time lost with the
  exams should be no problem, as this part of the work should take much less
  time and I also spent the "Community Bonding Period" coding.
* August 18: Firm 'pencils down' date. Mentors, students and organization 
 administrators can being submitting final evaluations to Google.