Article View: comp.sys.mac
Article #46183Re: AppleScan
From: Jef Poskanzer
Date: Wed, 14 Feb 1990 01:57
Date: Wed, 14 Feb 1990 01:57
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1595 bytes
In the referenced message, roy@alanine.phri.nyu.edu (Roy Smith) wrote:
} The way AppleScan (and,
}apparantly, most other bitmap manipulation programs) work is to take a
}greyscale image and turn it into a halftone bitmap, then send the halftone
}image to the printer. Wouldn't it be better to just take the greyscale
}image and send it to the printer and let the PostScript machinery do the
}halftone processing?
Yes. It's almost always better to use the grayscale scanning option
in AppleScan. If you're going to send the result to a printer, then
as you point out PostScript can do a better job of halftoning than
AppleScan can. And even if you want a bitmap for screen display,
any of the freely-available bitmap manipulation programs will also
do a better job of halftoning than AppleScan. For instance, my
PBMPLUS package does zig-zag Floyd-Steinberg error diffusion that
makes AppleScan's dithering look sick.
---
Jef
Jef Poskanzer jef@well.sf.ca.us {ucbvax, apple, hplabs}!well!jef
Alcohol 0% by volume.
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Path: arc1-ca.pugleaf.net!utzoo!attcan!uunet!seismo!ukma!wuarchive!mit-eddie!uw-beaver!Teknowledge.COM!unix!hplabs!well!jef From: jef@well.sf.ca.us (Jef Poskanzer) Newsgroups: comp.sys.mac,comp.sys.mac.hardware,comp.lang.postscript Subject: Re: AppleScan Message-ID: <16151@well.sf.ca.us> Date: 14 Feb 90 01:57:12 GMT References: <1990Feb13.233627.16665@phri.nyu.edu> Reply-To: Jef Poskanzer <jef@well.sf.ca.us> Organization: Paratheo-Anametamystikhood Of Eris Esoteric, Ada Lovelace Cabal Lines: 21