Affinity Publisher image profile conversion and PDF output question

[RWB]

I am having an issue debugging a color proofing issue with an on-demand publisher but have run into what I consider to be strange behavior in Affinity Publisher. Possibly a bug but wanted to get some input before I report it as a bug. I am using Affinity Publisher 1.9.3 on a Mac (with 10bit adobeRGB monitor calibrated well, etc... I print all the time with perfect color with local/custom printers as well as my in-house printing equipment)

My issue began as a proof copy I received that seemed to have a far cooler color rendition for every single photo than I expected and saw in my local proofing (either that or the reds/oranges/yellows are very desaturated in the proof copy).

In attempting to resolve the issue I decided to convert all of the placed images in the document to the document working profile (default CMYK/8) and export to a PDF version that will only support CMYK output as I suspected that the embedded AdobeRGB images inside a CMYK PDF was causing the problem for this particular printing service.

I set Affinity Publisher preferences to "convert opened files to working space" and to "warn" just to make sure placed images were being converted.

I get no warnings when I place AdobeRGB images in a Publisher CMYK working space document.

Am I completely misinterpreting what that preference option does? Should I be getting a warning if it is being converted?How can I ensure that images that are AdobeRGB (or any other RGB space) are actually being converted to the working CMYK and not being embedded with an RGB profile?

 

Thanks

[lacerto]

(...)

[RWB]

7 hours ago, Lagarto said:

You do not mention what kinds of images were placed in the document and whether color profiles were embedded in those images, and what your document and Publisher RGB default RGB color spaces are, but this sounds as if images processed with the AdobeRGB color profile had been placed in the document and assigned with the sRGB profile, resulting in generally lower color values showing good saturation in AdobeRGB color space becoming interpreted subdued because not being translated to lower-gamut sRGB color space. Something like here:

Note that this setting is for opened images (without or with conflicting profiles), not for placed ones. The placed ones without a color profile will get the document RGB profile (which by default is the one specified in the Preferences, until possibly overridden by the user). The default setting (not to convert colors but just warning about the conflict of color profiles when opening a file in Publisher, specifically if opening a PDF instead of placing it) works normally ok and is a safer choice.

The regular workflow for offset print jobs would be using a CMYK profile and then place photos etc. in RGB color space, with embedded profiles. In this case images can have varied color spaces (some images e.g. using Adobe RGB and some sRGB). Generally it is a good idea to have the publication document RGB color profile using sRGB (which it will have if you have not changed the default sRGB color profile specified for RGB under Preferences > Color). This way placed RGB images without a profile will get the sRGB color profile assigned to them, which is the likely color space for such images. If AdobeRGB would be used as the default, such images would be assigned with wider color gamut that they inherently have, resulting in opposite effect, colors becoming overly saturated.

By using e.g PDF/X1-a export method, or by manually checking the "Convert image color spaces" under the "More" options page available when exporting to PDF. 

pdf4job_wrong.pdf 4.18 MB · 0 downloads

Thanks for the clarification on the preference settings. 

 

As for the clarification on images I listed the color spaces of the images and publisher document implying that they have a profile tag but just to be clear; I am placing AdobeRGB images with AdobeRGB profile tag in a CMYK document. The document and export of "regular" PDF that has embedded RGB images with a profile looks fine on my calibrated 10bit AdobeRGB monitor. IE there are no missing profile information, no on my end AdobeRGB images are not being assigned sRGB and embedded in the document or PDF, etc.

My guess is that on the other end the embedded AdobeRGB images profile is not being respected/used.

My next proof I was guessing that using the PDF/X1-a would put out everything as CMYK period and I am using the convert image color spaces option. Thanks for the conformation. Looks pretty much identical for this set of images, I'll give it a try. If the proof comes back the same I'll have to assume they are setup to assume everything is sRGB some how and send a file with all embedded images converted to sRGB (which makes zero sense given I am assuming they are using typical HP indigo type gear for their print on demand stuff).

Just FYI this is Amazon CreateSpace which there seems to be absolutely zero info on specific color management or best practices for color when sending them a file. Only info available is some such thing as "all profiles are stripped out and then we do stuff" with zero specifics.

 

[lacerto]

(...)

[RWB]

On 7/13/2021 at 10:16 AM, Lagarto said:

I think they simply just discard color profiles and assign sRGB. That would explain this.

yep, ran three tests and that is EXACTLY what they do... doesn't seem to make any sense at all given typical Indigo color space would suggest that some images would benefit from Adobe RGB vs sRGB on those devices.

 

Ran three tests:

1. Embedded Adobe RGB in CMKY PDF = way wrong.

2. Adobe RGB converted to GRACOL CMYK on export = wrong, possibly less wrong.

3. US Coated SWOP v2 CMYK with embedded sRGB = not super critically accurate but by far the best. IMHO the worst way to do this on an indigo or similar device but I guess that's what they mostly get given default PDF export or something. How hard would it be to just deal with #2 or even do a conversion IF the profiles are there???

 

In any case serviceable color if you turn off everything you know about dealing with other shops. I guess they are extremely opaque about the process so they don't accidentally set an expectation of something with reasonably accurate color. Anybody have a clue if there's a "better" way than #3? I am assuming it turns out better in general than #2 as sRGB may have more gamut than converting Adobe RGB to SWOP??? Would have to check that.