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Author Topic: Z3100, Qimage, and Gamut woes  (Read 2863 times)

DotCom Editor

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Z3100, Qimage, and Gamut woes
« on: November 03, 2008, 08:57:48 AM »

Perhaps someone with more expertise can kindly educate me a bit.

I'm working on a fall foliage image with strong reds and yellows. In PS Softproof, with my APS-made HP ID Satin profile loaded, a few areas of yellow showed as out of gamut. Not a big deal I thought, since softproof is really just an approximation. So, I printed through Qimage, as I always do. The yellow out-of-gamut areas printed BLUE. The same thing happened a couple of months ago when I was printing sunflowers, again, predominantly yellow. I've just gone back and printed through Qimage again, but this time using the HP Preview to see the job before it goes to the printer (giving me a way to cancel). Yep, the out-of-gamut areas show as the same BLUE. I understand that blue and yellow are opposites; did I go so far off one end of the scale that I circled around the back side of the moon and re-emerged at the other end?

Now, let's complicate matters just a bit. I initiated the same print job, but from within PS, using the same profile and intent, taking Qimage out of the loop. (Softproof still shows the same areas out of gamut.) But, the HP Print Preview window no longer shows these areas as out of gamut. I sent the job to the printer, and voila, those areas printed correctly in yellow -- as they should -- not blue.

I do not believe my workflow is problematic. Could it be that PS and Qimage handle the same data differently? And where did the blue come from? I am definitely confused on this one. Thanks for your help.
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Paul Sumi

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Z3100, Qimage, and Gamut woes
« Reply #1 on: November 03, 2008, 09:07:34 AM »

If you haven't already asked there, the best place to get answers for QImage questions is on its Yahoo discussion group:

http://tech.groups.yahoo.com/group/qimage/

Mike Chaney, the program's author, and many experienced users hang out there.

Paul

Ernst Dinkla

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Z3100, Qimage, and Gamut woes
« Reply #2 on: November 03, 2008, 09:09:50 AM »

Quote from: DotCom Editor
I do not believe my workflow is problematic. Could it be that PS and Qimage handle the same data differently? And where did the blue come from? I am definitely confused on this one. Thanks for your help.


You should be confused on that one.
Send a message to the Qimage mailing list and ask what could have gone wrong.

http://groups.yahoo.com/group/qimage/

It could be the ICC profile category that isn't supported but write down all the aspects of the print settings, image data etc.




Ernst Dinkla

Try: http://groups.yahoo.com/group/Wide_Inkjet_Printers/
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Bruce Watson

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Z3100, Qimage, and Gamut woes
« Reply #3 on: November 03, 2008, 10:33:25 AM »

Quote from: DotCom Editor
...did I go so far off one end of the scale that I circled around the back side of the moon and re-emerged at the other end?
Could be. Depends on how the software was designed, then how it was implemented.

When ErgoSoft's StudioPrint v10 came out I was one of the first people using it for B&W with the Cone PiezoTone inks. In very light highlights I got black spots. Turns out it was a math error in their dither algorithm. In the extreme highlights they would run over the end of the buffer (65535) and recycle back to the beginning of the buffer (0), thus generating some use of black ink dots to make a white pixel. Disconcerting, and creepy looking. But they fixed it immediately and gave me a patch in less than a day so all was well.

Don't know that this is a problem with Qimage. But it's clearly possible.
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rdonson

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Z3100, Qimage, and Gamut woes
« Reply #4 on: November 03, 2008, 11:48:31 AM »

Quote from: DotCom Editor
Could it be that PS and Qimage handle the same data differently? And where did the blue come from? I am definitely confused on this one. Thanks for your help.

Yep.  Two different pieces of color management software dealing with ICC profiles.  Sounds like Qimage skipped a cog unless there's a problem with the profile.

You don't mention which rendering intent you were using.  Have you tried more than one?
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Regards,
Ron

William Morse

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Z3100, Qimage, and Gamut woes
« Reply #5 on: November 03, 2008, 12:40:31 PM »

As Ernst says, this is answered best on the qimage forum.

I have seen similar things in the qimage preview from 16 bit files with alpha channels. At least on my set-up, qimage doesn't seem to like them. Any chance this is what's happening? What happens when you try to print a flattened 16 or 8-bit version (with no alpha's)?

Bill

Quote from: rdonson
Yep.  Two different pieces of color management software dealing with ICC profiles.  Sounds like Qimage skipped a cog unless there's a problem with the profile.

You don't mention which rendering intent you were using.  Have you tried more than one?
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DotCom Editor

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« Reply #6 on: November 06, 2008, 02:17:08 PM »

Alas, no answer from the Qimage people on the Yahoo forum after three days.

To answer Bill Morse's question, I tried both perceptual and relative colormetric intents. No real difference.

Bill, any relation to the families of William B., Alfred, and Lester Morse?
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William Morse

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Z3100, Qimage, and Gamut woes
« Reply #7 on: November 06, 2008, 02:50:17 PM »

Actually, I didn't ask about intents; I would be surprised if that made any difference. I asked whether you had tried printing a flattened, 8- or 16 bit tif with no alpha channels, as I have seen problems, including similar to what you describe, from some tifs with alphas.

Bill

And no, no Morses of those stripes in my tree.

Quote from: DotCom Editor
Alas, no answer from the Qimage people on the Yahoo forum after three days.

To answer Bill Morse's question, I tried both perceptual and relative colormetric intents. No real difference.

Bill, any relation to the families of William B., Alfred, and Lester Morse?
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Wm. Morse Editions
A Fine-Art Digital Printmaking Studio
Photography, Limited Editions, Film Drum Scanning
Restored Early 20th Century Photos of China
www.MorseEditions.com

William Morse

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Z3100, Qimage, and Gamut woes
« Reply #8 on: November 06, 2008, 02:54:06 PM »

BTW, what's your OS; Mac (emulation) or PC?

Bill

Quote from: DotCom Editor
Alas, no answer from the Qimage people on the Yahoo forum after three days.
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Wm. Morse Editions
A Fine-Art Digital Printmaking Studio
Photography, Limited Editions, Film Drum Scanning
Restored Early 20th Century Photos of China
www.MorseEditions.com

DotCom Editor

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Z3100, Qimage, and Gamut woes
« Reply #9 on: November 10, 2008, 06:15:43 PM »

My OS is good ol' reliable 32-bit Windows XP SP3. My day job is writing about technology for the computer trade press, and knowing what I know, I stay far away from Vista.

I've been printing for years straight from unflattened PSD, sometimes containing just one or two adjustment layers, sometimes many more. I'll try flattening and see if that helps, and I'll also try saving as a 16-bit TIFF, though that's an extra step that should not be necessary.
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Paul Sumi

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Z3100, Qimage, and Gamut woes
« Reply #10 on: November 10, 2008, 06:26:50 PM »

Quote from: DotCom Editor
I've been printing for years straight from unflattened PSD, sometimes containing just one or two adjustment layers, sometimes many more. I'll try flattening and see if that helps, and I'll also try saving as a 16-bit TIFF, though that's an extra step that should not be necessary.

Are your PDS files saved as "maximize backward compatibility?" I have heard that QImage hiccoughs unless this is done.

BTW, I've been printing unflattened 16 bit TIFFs with multiple adjustment layers on QImage (currently Studio Edition version 2009 beta 200g) with no problems on an Epson 2400.

Paul
« Last Edit: November 10, 2008, 06:27:16 PM by PaulS »
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