Path: utzoo!yunexus!geac!syntron!jtsv16!uunet!seismo!sundc!pitstop!sun!hanami!landman From: landman%hanami@Sun.COM (Howard A. Landman) Newsgroups: comp.sys.next Subject: Re: WYSIWYG & DPI Keywords: WYSI*A*WYG Message-ID: <74769@sun.uucp> Date: 26 Oct 88 18:39:59 GMT Article-I.D.: sun.74769 References: <6937@orstcs.CS.ORST.EDU> <12908@oberon.USC.EDU> <2482@silver.bacs.indiana.edu> <31144@bbn.COM> <74013@sun.uucp> <148@internal. Sender: news@sun.uucp Reply-To: landman@sun.UUCP (Howard A. Landman) Organization: Sun Microsystems, Mountain View Lines: 85 >In article <74013@sun.uucp> landman@sun.UUCP (Howard A. Landman) writes: >>Here's a hard lower bound. Studies have shown that 2-bit grayscale >>gives you better "perceived" screen resolution than spending the same >>bits on extra 1-bit resolution. Since doing that would give you >>SQRT(2) more pixels in each direction, we know that the "effective" >>resolution of the 96-DPI NeXT screen must be AT LEAST 96 * 1.41 = 135 DPI, >>almost twice that of a Macintosh or Alto. In article <148@internal.Apple.COM> casseres@Apple.COM (David Casseres) writes: >We only know this if we know that the NeXT actually uses the 2-bit gray- >scale display to do grayscale anti-aliasing. I have the impression that >it does not; does anyone actually know? I too, would like the answer to this. However, assuming that NeXT *DOES* use fuzzy fonts and other antialiasing, I have a little more data. This comes from "The Media Lab: Inventing the Future at MIT" by Stewart Brand, p.170ff, which is Copyright (c) Stewart Brand 1987. Nicholas Negroponte is the director of the Media Lab. ------------------------------------------------------------------------------ The Media Lab has in its history a fine example of wrong exploiting - 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 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 violation." Aliased fonts are what you see on almost all computers. Each square pixel (picture element) on the screen is either black or white: one information bit per pixel. The problems come when you're representing 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 instead 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 doubling the number of pixels quadruples 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 antialiased the fonts and put in the same kind 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 ability 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 the circle were anti-aliased with a little gray with two-bit pixels, the people 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 until 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.) --------------------------------------------------------------------------- I'm puzzled by this last reference. Fuzzy Fonts on a Mac? Does anyone know more about this? At any rate, the above seems to indicate that two-bit anti-aliasing can get you about 2x resolution, so the NeXT is *capable* of an effective resolution of just under 200 DPI, *if* they implemented it. Howard A. Landman landman@hanami.sun.com UUCP: sun!hanami!landman