Here's the real reason why I implemented "create bitmap copy":
Via prefs, you can specify an external filter that will be run on the
PNG file after it is exported but before it is imported back. I use
this for grayscaling and blurring the image to create a soft drop
shadow for any object.
The script itself is share/extensions/inkscape-shadow.sh. It's not
integrated into the extensions or plugin system in any way (Ted, I may
need your help on this). The script requires Imagemagick 6.x to be
To enable this, you set in your preferences.xml:
In filter=, you specify either the full path to the script, or just
"inkscape-shadow.sh" if the script is in your PATH. The script
receives the image filename as the first parameter and the
filter_param1 as the second parameter (more parameters can be added).
This particular script interprets that as the blur radius in pixels,
but of course that depends on the script you use.
Now, I'm not going to provide a GUI for the blurred shadows feature,
for these reasons:
1. You have to carry around the shadow PNGs along your SVG. It's
inconvenient, and the PNGs may be much larger than the SVG.
2. The shadows are not resolution-independent and are not updated
automatically. For all this, we need to support the gaussian blur SVG
filter (a standard SVG feature). But since we don't have any filter
support yet, hence this hack.
3. Both Batik and Adobe have (different) problems with displaying PNGs
with alpha transparency. (Much like the Internet Exploder - shame on
Still, for those who desperately need blurred shadows right now (such
as myself), this feature works well enough. Try it out, it's fun.