Starting to create IWMA symbols in SVG

Trevor Jenkins trevor.jenkins at SUNEIDESIS.COM
Mon Jul 25 14:06:52 UTC 2005


Feeling inspired ;-) by discussions in the computer workshops at the First
European SignWriting Symposium I spent time yesterday playing around
creating some IWMA symbols as vector graphic images to supplement the
present bitmapped versions. Vector graphics have the advantage over
bitmaps in that they scale without introducing staircasing on diagonals.
Decided that the SVG format from W3C would be the format to use; W3C being
responsible for all standards on the World Wide Web and also for XML my
choice wasn't as random as it might appear.

Began by downloading an open source drawing program (INKSCAPE from
http://www.inkscape.org/ ) and making one symbol. Oh boy is that going to
be tedious! Ensuring that the stroke widths are the same for lines as for
rectangles; the program's default settings are different and then are the
symbols consistent in size and weight plus a host of other aesthetic
decisions needing to be made. And I haven't really got the patience to
create almost 26,000 symbols from scratch.

So tried a different track: download the existing PNG files and convert
them to SVG. There are several open source tracing programs available so I
downloaded autotrace from http://autotrace.sourceforge.net/ . The few
tests I've run suggest that this is a practical and more sensible method
of creating the initial SVGs. There is alternate tool potrace (available
from http://potrace.sourceforg.net/ ) that may occasionally produce better
conversions. Using autotrace and/or potrace in combination with other open
source graphics programs such as ImageMagik should provide all the tools
necessary. Time to convert one PNG file with autotrace is about a second
of real-time so converting every file would take about 8 hours.

But there is no need to convert every single one of the PNG files. Once a
shape has been converted its rotated and reflected variants can be
generated automatically. For example I only need one version of the G-hand
(IWMA symbol 01-01-001-01-01-01). All the other G-hands 01-01-001-01-01-02
through 01-01-001-01-01-16 are nothing more than simple mathematical
transformations. Reviewing and tweaking this much reduced set of converted
files with INKSCAPE will be faster too.

Next step is to try using an open source font creation programs to
generate some font files. Without realising what I was doing the font
creator I plan to use (fontforge from http://fontforge.sourceforge.net/ )
just happens to use autotrace and potrace to a capture bitmapped image
ready for tweaking as a font character.

This isn't going to be an overnight job but it'll keep me busy during my
summer break and beyond. ;-) Perhaps if a Second European SignWriting
Symposium is held then there will be something to show.

Regards, Trevor

<>< Re: deemed!



More information about the Sw-l mailing list