🚀 go-pugleaf

In article <1jvkv6INN1go@rave.larc.nasa.gov>
	arras@cobia-f.icase.edu (Michael Arras) writes:
>	Last week I asked whether or not it was possible to query a PS
>printer to find out if it had color capabilities.  The only responses I
>received mentioned that I should check if systemdict /colorimage is known.
>Unfortunately, this does not work.

Nonexistence of colorimage merely suggests that the interpreter
version predates PostScript Language Color Extensions.  It does
not indicate anything about the hardware characteristics.

>                                      I find it hard to believe that PS
>does not have a built-in set of commands that can be used to find out if
>the printer being printed on is a color printer or not.

Why?  PostScript is designed to be "device independent"--you're
not supposed to CARE where your document's going.

For what it's worth, Display PostScript and Level 2 have a
"deviceinfo" operator that returns [a dictionary containing]
information about color capabilities.

					-=EPS=-

arras@cobia-f.icase.edu (Michael Arras) writes:

>print it on (color or not color).  Someone mentioned that I redefine
>/colorimage, but this will not solve my problem, nor will it produce the
>correct output in the program above.  I find it hard to believe that PS
>does not have a built-in set of commands that can be used to find out if
>the printer being printed on is a color printer or not.
>
Device-indpendence does have a down side too:-).  Seriously, it's not
as clear cut as that.  On some (many?) printers you can look at the
value of processcolors to see how many primary inks your device
thinks it's got.  Trouble is, on devices that can produce both
colour and mono output, this can be a read/write value that you can
change to tell the printer what you want....  In recent interpreters
there may be a thing called deviceinfo available, which is descrbied
briefly in the Red Book II.

-- 
Ian D. Kemmish                    Tel. +44 767 601 361
18 Durham Close                   uad1077@dircon.co.uk
Biggleswade                       uknet!dircon!uad1077
Beds SG18 8HZ United Kingdom

[]

	"PostScript is designed to be "device independent"--you're not
	supposed to CARE where your document's going."

Yes and no.  You are able to write device independent PostScript code,
if you assume a page size.  But the interrogation features of
PostScript, when used with a bidirectional communication port, can make
the user's life a lot easier.  For example, I have seen helpful
applications that know whether the destination printer handles color,
and disables the select-color commands if not.  This sort of immediate
feedback can help decrease the number of the user's misconceptions.

Macintosh users take this sort of thing for granted, because AppleTalk
is bidirectional.  IBM PC users do not, because the typical parallel
port is unidirectional.

  -=- Andrew Klossner  (andrew@frip.wv.tek.com)
                       (uunet!tektronix!frip.WV.TEK!andrew)