The Raster Tragedy at Low-Resolution Revisited
At a training session on occasion of the OpenType Font Jamboree in 1997, I gave a presentation about rendering outline fonts on low-resolution screens. At the time, text was rendered in “black-and-white” by turning pixels “on” or “off.” I illustrated how naïvely scaling the outlines and turning “on” the pixels inside the scaled outlines resulted in severely malformed characters.
Shortly thereafter, the slides of the presentation were converted to <html> and added to the Microsoft Typography website as The raster tragedy at low resolution. Over time, a surprising number of documents in cyberspace started to refer to the raster tragedy—amongst others, threads on Typophile (cf also Typophile), patents granted by the US Patent Office, and encyclopedia articles on Wikipedia. Eventually, some of these references also started to point out that while its fundamentals may still be valid, the raster tragedy does not address any anti-aliasing methods.
Accordingly, I started contributing to discussions in mailing lists and on Typophile. But without “infrastructure” to build upon by reference, there is only so much content you can cram into a single post and keep it self-contained. For instance, in ClearType, in XP and Vista on Typophile I tried to explain the raster tragedies of text layout—a post which promptly got quoted slightly out-of-context in Wikipedia’s page on ClearType.
Therefore I eventually decided to put it all together in one place, instead of scattering individual answers to the font rendering puzzle, in hopes that this may be of any use to end-users, font makers, and software developers alike. This website is the result of this endeavor. And last but not least, the phrase Raster Tragedy originates in a publication by URW’s Peter Karow[1]—credit where credit is due!
Start reading →