🚀 go-pugleaf

lilleyc@cs.man.ac.uk (Chris Lilley) writes:

>In article <1992Dec15.194635.18632@udel.edu>
>pyrros@braindamaged.cis.udel.edu (Christos T. Pyrros) writes:
>
>>NeXTSTEP 3.0 includes Display PostScript Level 2, with Pantone color matching.
>>It just works! (tm).  It also does CMYK, RGBA, etc.  Which also means that my
>>laser printer, and any dumb device that will accept a bitmap from my machine
>>effectively becomes PostScript Level 2!
>
>Well, sort of. But it will not support all the level 2 features. For
>example, you will not be able to specify a colour in (say) CIE XYZ and
>have it come out that colour on your printer - which is a major reason
>many people want level 2 printers in the first place. What will happen
>is that the DPS interpreter will calculate the RGB values required
>for your _screen_ to display that colour. The printer, on getting
>those values, will print out a colour based on dumb RGB->CMYK
>conversion, not the colour you would have got with a true Level2
>interpreter on your printer.

This is wrong!!  Of course, sending to a Level 1 device will have the
effect you described (although there are ways around that as well),
but the original poster specifically mentioned 'dumb' devices that
will let the NeXT do the rendering.  Once the rendering dictionary
for the printer is set up (with the proper driver), you're all set.

I always use a CIELab test sheet to test my driver.

>Also, I suspect that using DPS to render at, say, 100dpi and then
>sending this lo-res bitmap to a colour imagesetter is not the route to
>high quality ;-)

Why would I let DPS render at 100 dpi?  For CLC-300/500, Cj-10 and the
A1 BubbleJet (all by Canon) I render at 400 dpi in 24 bit color, for
the Seiko PhotoMaker at 300 dpi, also in 24 bit.  The most serious
limit is the license, which sets a cap at 800 dpi, but that would
seem quite enough to me, for anything except imagesetters, and you
can always get an extnded license from Adobe, or work around the limit
(several schemes come to mind immediately..)

>Of course, I am not knocking NeXT in any way by these comments. They
>have done a fine job in getting a DPS together based on Level 2, and
>will hopefully spur other DPS vendors (DEC, SGI, and now Sun) into
>following suit.

Well, you were, even if you didn't intend to.  Apparently they've done
an even finer job than you thought.

Marcel