From: freek@phil.ruu.nl (Freek Wiedijk)
Subject: Re: "Hinting" using antialiasing? A GNUish alternative...
Organization: Department of Philosophy, University of Utrecht, The Netherlands
Date: Fri, 25 Dec 1992 17:48:17 GMT

Yet another follow-up to the same article...  I _like_ this subject!

pcg@aber.ac.uk (Piercarlo Grandi) writes:
>
>On 17 Dec 92 19:32:08 GMT, uad1077@dircon.co.uk (Ian Kemmish) said:
>>
>>The only real survey I saw done on anti-aliased text (John
>>Amanatides?  I'm not sure - I'll go and check)
>>showed that prolonged viewing of anti-aliased text induced more
>>eyestrain than decently tuned bilevel text.
>
>Ah, this is another matter entirely. If so, it's unfortunate.

From Steward Brand's `the Media Lab', pages 170-172, reproduced without
permission:

-------------------------------------------------------------------------------
   The Media Lab has in its history a fine example of wrong exploit-
ing---an excellent, simple idea, instantly applicable, available free to
anyone, that has sat on the shelf, in plain view of the world since 1971.
   Called Fuzzy Fonts, it is a cheap, easy way to have much higher
resolution print on computer and TV screens.  Negroponte: "It's not
subtle.  When you see it, you gasp."  He's right.  Characters on the screen
look just beautiful, like on paper, and you can read them even if they're
tiny.  On a TV set ordinary fonts are usually presented forty characters
on a line, maximum sixty characters.  Fuzzy Font characters are still easy
to read at eighty characters per line, and you can go up to 100.
   "Having to look at stairstep characters and jaggies should be against
the law," declares Negroponte.  "Aliased fonts should be an OSHA vi-
olation."  Aliased fonts are what you see on almost all computers.  Each
square pixel (picture elemnt) on the screen is either black or white:
one information bit per pixel.  The problems come when you're repre-
senting a sloping line and you see a jagged edge instead, or the serif at
the tail of a character is smaller than a pixel and it disappears entirely.
   "Anti-aliasing" smooths the jaggies by introducing a little gray in
the right places.  With two-bit pixels instad of one-bit you have the
choice of black, white, or two shades of gray.  That disappearing serif
can be represented by a light gray pixel, and your eye reads it as a serif.
It's cheap because doubling the resolution this way only doubles the cost,
whereas doubling the resolution by increasing the number of pixels quad-
ruples the cost---four jaggy one-bit pixels instead of one fuzzy two-bit
pixel.
   Negroponte: "I personally have exposed tens of thousands of people
to Fuzzy Fonts since Paula Mosaides---I remember her name because
she was Greek---got us started with this back in 1971.  The only semi-
convincing argument against it I've heard is from people who claimed
that the eye seeks out crisp edges, and if it encounters nothing but fuzzy
edges it gets much more tired.  That turned out to be wrong.  Acuity is
                                ^^^^^^^^^^^^^^^^^^^^^^^^^^^
sharpness of the image; resolution is some measure of the finest level of
detail that you can read.  They are not the same at all. You can give up
acuity and gain resolution.
   "Now, IBM ran an experiment where they presented the reader a
page with a number of typographical errors in it, and the person was
supposed to read the page and find the typographical errors.  They would
do it on paper, then do it on a screen with different errors but the same
number of them.  With a normal IBM or Macintosh screen they were
something like 60 percent less efficient than on paper.  Then they anti-
aliased the fonts and put in the same kinds of errors, and people came
up with 98 percent of the efficiency of paper.  So Fuzzy Fonts on a screen
are the closest approximation to paper in terms of your abitlity to read
them."
   Another test had people bringing a line on a screen to just touching
a circle on the screen.  If the line and circle were anti-aliased with a little
gray with two-bit pixels, the pople were twice as precise.  It is not just
an aesthetic effect.  Fuzzy Fonts may be the Media Lab's single most
proven commercial idea.  Why it had to wait till 1987 to become a product
is a mystery.  (Apple finally introduced Fuzzy Fonts on their second-
generation Macintosh computers in spring, 1987, followed by IBM.)
-------------------------------------------------------------------------------

Freek
--
Third theory of Phenomenal Dynamics:  The difference between
a symbol and an object is quantitative, not qualitative.
Newsgroups: comp.fonts