iamson??at?May?17??95?10?24?31?am@bnr.ca>
content-type: text/plain; charset=US-ASCII
organization: University of Illinois at Urbana
mime-version: 1.0
reply-to: grassu-list@max.cecer.army.mil
newsgroups: info.grass.user
originator: daemon@ux1.cso.uiuc.edu
Malcolm Williamson writes in response:
I guess my response is, no, I'm not positive. Images created using ps.map
and printed on a 24-bit dye-sublimation printer are _definitedly_ more
than 8-bit, but they could be something less than 24-bit. They _look_
like "true-color" to me, though. Are you sure that ghostscript is capable
of displaying 24-bit, regardless of whether the PostScript image is?I suppose I could look in the trusty PostScript reference manual to
finish this debate...
In my case, a little knowledge could be a dangerous thing here, but here goes
anyway. When ghostscript displays anything, it calls the 'x11' driver. One of
the first things that driver must do is make an Xlib call to open a graphics
window, in the same way that the Grass Xdriver does. On both Suns and SGI's,
the default window is 8 bit pseudo colour, unless otherwise instructed. Now
for the big questions: (a) does ghostscript have the capability of determining
whether the data is 24 bit, and (b) does it bother to check the capabilities
of the display system?
--
Conn V Copas
Information Technology Division
Defence Science and Technology Organisation
PO Box 1500
Salisbury tel: +61 (0)8 25 95349
SA 5108 fax: +61 (0)8 25 96781
Australia e-mail: cvc@itd.dsto.gov.au
-------------------------------------------