(excuse me for cross post... but there are many sections of the forum about LCD/LED displays
As a side project of ht1632 library for Arduino, I wrote also a dotmatrix editor for fonts and bitmaps: http://code.google.com/p/dotmatrix-editor/
I wrote it in Perl-GTK... sorry but I'm not so good with Java. Anyway it should be portable/runnable on any OS with Perl and some Perl libraries (on the project Wiki there are basic instructions for Linux, Windows and OSX users).
It's a first working release, almost working... can you test it and say me how did it strike you? Any suggestions?
(...and yes, I know, the editor resemble a bit Minesweeper
In the next release I'll add a text box to copy and paste results in form of C array fragment (for now, because direct saving to file is difficult and time consuming to develop).
If somebody is available to contribute I'll happy to add as project member on Google Code.