#720 DNP DS620a Color issues on Raspberry Pi 3 (Raspbian)

[Benjamin Willard]

Hello I have an issue with the color profiles and I've been trying to fix this issue for months.

We had 5.2.11 Gutenprint pre-installed on cups with Raspberry Pi 3 Model B+ without the GUI interface (Raspbian). And tried to upgrade to 5.3.4 to see if this issue would fix it. We also tried upgrading cups to the latest version as well.

The image on the left printed out is from the MAC version of Cups using default DNP DS620a drivers and configurations where the one on the right is the DNP DS620a configuration that comes with gutenprint53+usb default.

As you can see the one on the left (which is the CORRECT color) version and the one on the right is not the correct one as the green is more offset color as it shouldn't be.

Any assistance on how to get this to work and instructions provided would be much appreciated.

Benjamin

[Robert Krawitz]

There's no 5.3.4; do you mean 5.3.1?

Treating this for now as a dyesub driver issue.

[Robert Krawitz]

...or I should have said, assigning it to the dyesub driver maintainer :-)

[Benjamin Willard]

Yes, I meant 5.3.1... Been typing versions all day lol....

I have attached the original image so that if you guys want to test you can do so.

Thank you

[Solomon Peachy]

The manufacturer Mac drivers come with an ICC profile that is almost certainly enabled by default.

Here is the ICC profile that they supply with their Windows driver. [1] I believe Debian's CUPS build is set up to automatically work with colord, so you can register the ICC profile with it and it should justwork(tm). Alternatively you can apply the profile directly to the image before you print it.

Also, I recommend these settings:

StpColorCorrection=Raw
StpColorPrecision=Best
StpImageType=Photo

[1] http://git.shaftnet.org/cgit/selphy_print.git/tree/icm/DNP/DNP_DS620/DS620-R0.icc

• Solomon

[Benjamin Willard]

Hi Solomon,

This is the exact same file I have that I tried testing with. The issue is that we are using raspberry pi raspian and the colord shows the image correctly when I use fbi command line. When we just run the default lp "414475_625680.jpg" as the default printer with no changes. I have done Raw/Best/Photo and ran it again and it still didn't do anything...

I have also tried using colormgr import-profile on that icc and it won't import it and says "The profile was not added in time"

I should also mention that I am not using any user-interface to manage these so I have to rely solely on the command line.

I am also using Raspberry Pi 3, Raspbian which will be slightly different than Debian. So I have had no luck even with with your suggestions.

Ben

[Benjamin Willard]

Hello Solomon,

Any thoughts on what I can do to make this work?

Benjamin

[Solomon Peachy]

About a month ago I fixed a long-standing bug that applied an incorrect gamma curve to all dyesub printer (including the DS620). We haven't had a release with the fixed code but if you can build from source the results should be a lot better.

[Victor Arribas]

How did you manage to fix this bug? I'm having some issues with DNP RX1 HS.
I've the i1Studio spectometre and could manage an ICC profile for DS620 and RX1HS but still is not perfect enough.

Kind regards,

[Solomon Peachy]

If your DS620 or RX1HS's PPD doesn't have a paramter called 'StpLegacyDyesubGamma' then you are not using a build with the gamma correction fixes. With that fixed code (and StpLegacyDyesubGamma set to False) a color-managed workflow using the manufacturer's ICC profile will yield results consistent with their Windows driver.

[Solomon Peachy]

I'm going to close this as it is fixed to the best of my knowledge. If this problem is reproducible with the current (ie 5.3.4-pre or newer) code, please re-open it.

[Victor Arribas]

The problem of similars colors of turquoise or aquamarine is still now working properly. The results are far away of good results. Could you please help us to solve this point?
If interested, you can check printing the following color with DNP printers.
CMYK (c, m, y, k): (40, 0, 20, 0)
RGB (r,g,b)B: (159, 213, 209)

Regards,

[Solomon Peachy]

You need to provide more information:

• What gutenprint version
• What ICC profile you are using, if any
• Gutenprnit settings (notably StpLegacyDyesubGamma)
• How you are submitting the image (ie what application, etc)

And finally, what working colorspaces are those RGB & CYMK points from, and how do you know the printer is even capable of rendering them?

[Stefan Mehner]

Hi Solomon,
I have the same issue.
Here are the needed infos:

• gutenprint version: 5.3.4

• ICC profile: 'default' <- I don't know how to change.. I tried several ICC profiles from DNP directly using several approaches but the result was the same again and again

  • gutenprint settings: (I configured everything with the CUPS web interface)
    • "Use legacy dyesub gamma curve:" no | yes (tried both - no change)
    • Raw/Best/Photo <- tried a lot of combinations with no visibile changes
    • submission: I create a jpg within a c++ application using opencv2 and print this file using simple lp filename.jpg
    • colorspace: we tried both cmyk and srgb while image creation as well as in DNP CUPS settings.
    • When changing the CUPS colorspace there war some differences, but depending in the specific image sometimes cmyk is better and sometimes rgb.

  May I attach the original file and the resulting printouts using different settings?

  Thank you a lot.

  Best,

  Stefan