Re: [ft] Compressing CJK Fonts effectively

[Michiel Kamermans]

Matthew Tippett wrote:

I am working on an embedded project which requires CJK truetype fonts.  Since it is an embedded system, I want to save as much disk space as possible.  The fonts we are using seem to compress to about 70% of their original size - which could save around 13 MB on the ROM image.  I noticed the post in 2002 from David Turner when he completed the gzip support talking about not wanting to encourage stupid choices (like gzip-compressed truetype fonts).  What is the current best practice for managing large CJK fonts in a storage efficient manner?

First check if those fonts exist as OpenType with PostScript Type 2 outlines (CFF). If so, done: use those, that's about as small as the font's going to get, because CFF glyphs are defined in terms of both normal vector instructions as well as glyph subroutines, so shared features between glyphs (and in CJK fonts that can be tens of thousands of features) can be stored as subroutines and remove a bucketload of bytes from the filesize.

If they don't exist as OT(CFF), then you can try to run your font through Adobe's "tx" tool, which is freely available as part of the Font Developer Kit (http://www.adobe.com/devnet/opentype/afdko/). You will lose any hinting that's in the truetype font, but the FDK also comes with autohinter that is pretty much as good as hinting's going to get. Of course, this may also be illegal for the font you're using, so make sure you have the right to create derivatives before you go down that road.

- Mike "Pomax" Kamermans
nihongoresources.com