Ubuntu
freetype package

Bad font rendering (Freetype, bytecode interpreter)

Bug #415134 reported by Lasse Kärkkäinen on 2009-08-18

This bug affects 2 people

Affects		Status	Importance	Assigned to	Milestone
	freetype (Ubuntu)	Fix Released	Undecided	Unassigned

Bug Description

A screenshot demonstrating the issues: http://zi.fi/fonttest/fonttest-bytecode-enabled.png

The shot was taken with Ubuntu 9.04 fontconfig-config default settings, AA enabled, full hinting enabled, subpixel rendering disabled (in Gnome settings). The text is written in OpenOffice ( http://zi.fi/fonttest/fonttest.odt ).

Times New Roman italic z is missing the diagonal line (or in fact it is just extremely thin). All Microsoft fonts display bad kerning (possibly due to OpenOffice) and sudden line thickness changes in italic text of different sizes (hinting switching to 2 pixel lines instead of 1 pixel would explain the change, but without hinting as is the case in italic text this makes no sense). The free fonts (which presumably contain no bytecode) have no hinting at all, not even in regular rendering (soft edges on FreeSans and FreeSerif titles).

Freetype autohinter should be used at least for the fonts with no bytecode in them and possibly for all fonts, as it often seems to produce better results than the bytecode does. This is because the bytecode is designed for non-AA rendering. Microsoft's workaround is to disable AA entirely in smaller sizes, but that doesn't produce very good results either.

I am reporting this against Ubuntu because apparently it is the patches that Ubuntu use that break this instead of Freetype itself being broken. Times New Roman bytecode in deed seems broken (for anti-aliased rendering at least), but an easier and possibly better fix would be to enable the autohinter, which seems to have very good rendering quality.