ftp.nice.ch/peanuts/GeneralData/Usenet/news/1989/CSN-89.tar.gz#/comp-sys-next/1989/Oct/Halftones

This is Halftones in view mode; [Up]

Date: Sun 18-Oct-1989 05:45:42 
From: Unknown 
Subject: Halftones

This is really a PostScript question, but I am interested in the answers
for the NeXT Megapixel display and printer.

To optimize the the 'transfer function' of some imagery
I'm interested in knowing, for the default screen and spot function:
	a) the number of 'distinct' halftones
	b) the relative density of each, eg, which elements of this set
	correspond to what ranges of grey.

Can one determine this analytically using the PostScript 'currentscreen'
operator?  It seems that one would need to know the form of the spot
function....

For the printer, I've run some strip tests and get 'at least 20,  maybe 36'
as the number of distinct halftones. Problem is that the printer is too
good, in the mid greys I can't distinguish the bands to get a count.

Thanks


Glenn P. Davis
UCAR / Unidata
PO Box 3000                   1685 38th St.
Boulder, CO 80307-3000        Boulder, CO  80301

(303) 497 8643


>From: nevai@gem.mps.ohio-state.edu (Paul Nevai)

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