Path: utzoo!utgpu!attcan!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: <74013@sun.uucp>
Date: 21 Oct 88 18:04:51 GMT
References: <6937@orstcs.CS.ORST.EDU> <12908@oberon.USC.EDU> <2482@silver.bacs.indiana.edu> <31144@bbn.COM>
Sender: news@sun.uucp
Reply-To: landman@sun.UUCP (Howard A. Landman)
Organization: Sun Microsystems, Mountain View
Lines: 24

In article <31144@bbn.COM> mthome@BBN.COM (Mike Thome) writes:
>With respect to DPI levels of NeXT hardware:  Given the actual DPI values
>of the display (*ROUGHLY* 100dpi) and the lzpr (400dpi or 300dpi) you
>should keep in mind that assuming the display postscript interpreter is
>any good at all (i.e. does some sort of anti-aliasing) and the display
>has a 2-bit grayscale, even the relatively low resolution level provided
>by the screen ought to look FAR better than it's dpi figure would
>suggest... maybe someone out there knows how to compute an "effective"
>dpi rating for a 2 bit screen?  Is it, in fact, ~200 "e"dpi?

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.

If anyone familiar with those studies can provide a number saying
how much better the grayscale was, then just multiply 135 by that
factor (which should be slightly greater than 1.0).

	Howard A. Landman
	landman@hanami.sun.com
	UUCP: sun!hanami!landman