Splitting color and B&W pages....

[JNJ]

A client hit with me a request that I find I'm a bit stumped on. I don't
think it's possible, but thought I'd toss it out there anyway.

The client has an office of about 6 or 7 systems. They regularly print
documents that contain pages in color and B&W. What they would like is a
system that could automagically interpret between the two and shunt them
accordingly -- i.e., B&W goes to a B&W only printer and color goes to a
color printer.

The goal here is of course cost savings -- color solutions are typically far
more expensive than B&W solutions. Even a device that could reduce the
associated costs would be an acceptable option.

Does anyone have any suggestions?

James

 

[JNJ]

So the color and b/w printer are of different type and probably use

different languages - as I understand from the user point of view there
should be only one "virtual" printer?

That's about the size of it. Kind of a crazy request, but it makes sense
when you think about the cost differential between B&@ and color.

I would think about printing in postscript and sending files to a linuxbox
which first scans if they contain color commands, and then redirects them to
color or b/w printer via postscript interpreter.

Hmmmm...that's a thought, but it would have to interpret the doc page by
page. Do you know of an app/script that can do that?

James

 

[JXStern]

The client has an office of about 6 or 7 systems. They regularly print
documents that contain pages in color and B&W. What they would like is a
system that could automagically interpret between the two and shunt them
accordingly -- i.e., B&W goes to a B&W only printer and color goes to a
color printer.

The goal here is of course cost savings -- color solutions are typically far
more expensive than B&W solutions. Even a device that could reduce the
associated costs would be an acceptable option.

Isn't this an obsolete concern?

If you print a mixed job on an ink-jet printer, B&W pages use only
black ink and are generally cheaper thereby, and even color pages cost
according to coverage, not just because they are color.

If you have some huge B&W only jobs and want to send them to a
super-low-cost printer, well, send them! Can't the system queues on
even such a low-rent system as Windows be set up to route totally B&W
jobs to one printer and other jobs to another? Not that I've ever
tried.

What kind of print volume of B&W and color are we talking here?

J.

 

[JNJ]

Isn't this an obsolete concern?

Depends on the installation. Admittedly, it's not really the way I would do
things (and I'm working on a better solution of course) but it's a valid
query.

If you print a mixed job on an ink-jet printer, B&W pages use only
black ink and are generally cheaper thereby, and even color pages cost
according to coverage, not just because they are color.

True. I think this particular client is looking at high price of inkjet ink
period. They also have a slightly unique set up that includes a
copier/printer (full size) as well.

If you have some huge B&W only jobs and want to send them to a
super-low-cost printer, well, send them! Can't the system queues on
even such a low-rent system as Windows be set up to route totally B&W
jobs to one printer and other jobs to another? Not that I've ever
tried.

I've never tried and I do not know -- ergo the question. We have something
of a user issue here (big surprise) -- they like being able to click PRINT
and have it do its thing. IMHO, just switch between printers depending on
the document -- heck, you're prompted for printer selection on each job
anyway, how hard is to pick at that time or, in the case of a mixed doc, put
the page numbers in to do it manually? But clients are clients....

What kind of print volume of B&W and color are we talking here?

Unknown -- enough that the client would like to find a way to do it though.

James

 

[Jerry Schwartz]

Having read the other messages, I think that going Postscript is the only
way to do it. The two printers undoubtedly have very different drivers, so
there's no way that capturing the spooled output would work.

Note that this means the client would have to spring for a server to
intercept all of this stuff (if they don't already have one), and some
custom scripting to hack the spooler. That wouldn't be cheap, and would have
to be maintained. I'm not sure where that generic Postscript driver is going
to come from, either. Some printers come with Postscript drivers, some do
not; and the spooled file would undoubtedly have printer-unique code in it
to tell the printer which mode (native or Postscript) to use. The custom
scripting would have to strip that stuff out and then regenerate it as
needed.

While Adobe Acrobat comes with a PDF driver, that's not the same thing
(although it could be used, with enough contortions) and you'd need a copy
for each workstation.

Also, Postscript doesn't support every possible feature of every printer; so
the clients may not see exactly what they want. For example, printing to a
color LaserJet in its native, PCL format I could create degrees of
transparency (for example, to shade a paragraph with a red overlay); the
same application, printing the same file with a Postscript driver, would
print an opaque red rectangle and the text wouldn't be visible. Watermarks
gave the same kind of problem.

 

[JNJ]

Having read the other messages, I think that going Postscript is the only

way to do it. The two printers undoubtedly have very different drivers, so
there's no way that capturing the spooled output would work.

Note that this means the client would have to spring for a server to
intercept all of this stuff (if they don't already have one), and some
custom scripting to hack the spooler. That wouldn't be cheap, and would have
to be maintained. I'm not sure where that generic Postscript driver is going
to come from, either. Some printers come with Postscript drivers, some do
not; and the spooled file would undoubtedly have printer-unique code in it
to tell the printer which mode (native or Postscript) to use. The custom
scripting would have to strip that stuff out and then regenerate it as
needed.

While Adobe Acrobat comes with a PDF driver, that's not the same thing
(although it could be used, with enough contortions) and you'd need a copy
for each workstation.

Also, Postscript doesn't support every possible feature of every printer; so
the clients may not see exactly what they want. For example, printing to a
color LaserJet in its native, PCL format I could create degrees of
transparency (for example, to shade a paragraph with a red overlay); the
same application, printing the same file with a Postscript driver, would
print an opaque red rectangle and the text wouldn't be visible. Watermarks
gave the same kind of problem.

Hmmmm.... I just can't see it worth the time and hassle of setting up a
Linux box and creating the code necessary to make this sort of thing work.
While the former's no biggie, the latter would be a royal pain.

I'm looking at a toner based color laser, preferable one with a refillable
system. It seems to me that this would be roughly the equivalent in TCO as
a B&W laser and color inkjet.

James

 

[Jerry Schwartz]

I didn't say it made sense. ;<)

A color laser might be a better bet. I'm not sure what you mean by a
refillable system, I think they all use separate toner cartridges for each
color. Color lasers have a smaller gamut than inkjets, though; I don't know
what kind of color output your client needs. I'm most familiar with some of
the older models, and what looked like a decent set of presentation colors
on your screen could turn garish or illegible when printed. They were slow,
too, even when doing just B&W.

 

[JNJ]

I didn't say it made sense. ;<)

LOL

A color laser might be a better bet. I'm not sure what you mean by a
refillable system, I think they all use separate toner cartridges for each
color. Color lasers have a smaller gamut than inkjets, though; I don't know
what kind of color output your client needs. I'm most familiar with some of
the older models, and what looked like a decent set of presentation colors
on your screen could turn garish or illegible when printed. They were slow,
too, even when doing just B&W.

The new batch of color laser printers are worthy of consideration. The
middle spectrum can print a respectable 10-17ppm and the colors are very
high quality. We had a sharp Tektronix at a job one time -- was really
slick.

By refillable toner cartridges, I'm referring to a printer that has bins for
each color (usually cylinders actually) and you simply tap the toner into
each to refill them, buying containers of each color. I saw an HP once that
was like that. They certainly were not inexpensive, but the flexibility is
nice.

FWIW, if anyone has a suggestion on a color laser printer, I'm up to hearing
it as well -- I'm never above advice. At this point I'm pretty much
leaning towards HP's line.

James

 

[Bob Hosid]

Xerox on the large DocuTech series of printers offers software that will do
Color Splitting, and its not easy. On input to a server, the input file is
parsed for pages that contain color printing. You have to pay attention to
the page, is it odd or even (for duplex printing). The color pages are
written to a separate file and submitted to a large color printer (laser,
not inkjet). This is very useful in large printing needs where color does
have a cost difference. Anyway, this separate file is sent to the color
printer for X copies that are required. The parsed file is put back
together with just the remaining pages (all black-white) and queued as a new
job. On the front of this file is a job ticket that instructs the DocuTech
what to do. The color pages (all sets) are put back into the DocuTech in a
special tray called the interposer which will feed pages and not image on
them. Its done "Post-Fuser" The instructions tell the Docutech to print all
the black & white pages and pull the already printed color pages from the
interposer making a completed book which can be bound, stapled etc.
I hope this sheds some light on the subject, it can be done but it really
takes special printers with dynamic controls to make it seamless in a
product environment.

Bob

 

[Lukasz Spychalski]

Do you know of an app/script that can do that?

No, but I think, that a person with good knowledge of postscript and a
language like Perl should be able do write such app - I hope that it's
possible to separate color pages by parsing a PS file.

Best regards
Lukasz

 

[Jerry Schwartz]

I think that's how they all work, or perhaps the bins themselves are
replaced on some models. It could get messy, there was always a little
spillage when refilling the hoppers.

I've only used HP. As a stockholder, I recommend them; as a laid-off
employee, I suggest that you look at alternatives.

 

[Warren Block]

No, but I think, that a person with good knowledge of postscript and a
language like Perl should be able do write such app - I hope that it's
possible to separate color pages by parsing a PS file.

It's not very practical, unless you limit the applications used by the
users. Most PostScript files have a prolog that contains customized
shortcuts for the commands; company A might use "sp" for the showpage
command, while company B uses "S".

So the commands you are looking for are very likely going to differ from
one print job to the next. You can't just look for color commands,
because those may be present in the general-purpose prolog, but not
actually used in the following pages. This might make it difficult even
if all the print jobs are coming from a single driver.

 

[Mike Pepe]

Hmmmm...that's a thought, but it would have to interpret the doc page by
page. Do you know of an app/script that can do that?

James

James, I'm sure this is feasable with some printer scripting and
filters. The big question is: is it worth the hassle for the
sub-pennies-per-page this would save? Unless they're printing hundreds
of thousands of pages a month, I don't see how it would be useful.

On a per-page basis, this becomes a nightmare, as b&w pages get spit
out one printer and the color ones get spit out somewhere else,
leaving the users to determine who gets what pages and how to
reassemble them.

I think reasonable office prudence would be a lot simpler: don't print
to the color printer unless you really need to.

 

[Jan Gregor]

It isn't but I think postscript is needed. Ghostscript can produce
pictures in png - lower DPI should be good enough. In python is for
example image library that produces histogram for given image. Than you
will see it there's some color in image and make the decision where
document should be printed.
Of course you need drivers for all printers in ghostscript.

Jan