Colour management - RGB Profiles

[thomaso]

I notice irritations with color profiles when a.) placing an image and b.) after PDF/X-4 export:

Document: RGB  |  Document Profile: "ECI rgb v2"
2 Pages, 2 Images: 1 RGB (sRGB IEC61966-2.1), 1 CMYK (ISO coated v2 ECI)

a.) Placing images:
– regardless of activated/deactivated convert and warn colour preferences:
When placing an image no profile warning appears.

b.) Exported PDF:
– regardless of the setting in export profile options ("default" or "document" or "rgb"):
• PDF Output Intent after export: "U.S. Web Coated (SWOP) v2 (Custom)".
Where this profile even does not appear in the pulldown list of export options.
• Both images got converted to RGB (the CMYK profile seems to became ignored).
 

___________________
Luckily in an CMYK document with CMYK PDF export:
• there is the selected documents profile (and no such U.S. Web profile) after PDF export.
• also both images still have their profiles assigned.
But when placing an image no profile warning appears, too.

[Chris_K]

Hi thomaso

I'm going to need a lot more detail about what is in your document. What sort of image are you placing? Are they jpgs or pngs or something else? 

Your report is not very clear on what you are expecting to see, when exporting to PDFX4 are you expecting it to be in RGB? Part of the X4 spec is it has to be in CMYK and U.S. Web Coated (SWOP) v2 is the default CMYK profile. You mention where this profile does not appear? What PDF settings is this in relation to?

Can you provide some screenshots or video do demonstrate what you are seeing or even the file with the image you are importing and exactly what export settings you are using?

Thanks

[thomaso]

>> when exporting to PDFX4 are you expecting it to be in RGB?

Yes, if RGB was selected as export color space/profile, than I do expect RGB.
• In the mentioned trials above (b.) there are RGB images in the resulting PDF as expected – but with CMYK output intent for the PDF. THIS is what confuses me. Instead I'd expect my document color space and profile (set in Document Setup > Colour > Colour format, Colour Profile) to become the output intent profile, too.
• Also I would expect to get "warned" when I paste a file with a different color space than the document's, if this option is activated in Applications "Preferences" > "Colour". (screenhot left)
• Another confusion here is the function and setting of the two buttons "Assign" and "Convert". I don't know how I may prefer "Assign" generally, cause once I select it and enter OK + close the window, then next time "Convert" is active again. (screenshot right)

    

>> Part of the X4 spec is it has to be in CMYK ...

Not necessarily. Since PDF/X-3 also RGB or even CIE are possible/allowed.
But if AFPub really intends to limit and reduce the PDF/X-4 color space to CMYK (which would be a pity), then the UI should prevent the user from choosing a different color space after selecting PDF/X-4. (compare in the UI: when PDF/X-1 got selected then RGB is not available any more)

 

>> ... and U.S. Web Coated (SWOP) v2 is the default CMYK profile.

Hm. Imho there is no such "the" default profile for PDF/X. Rather, the idea of standardizing PDF/X is to make it easier, more error-free and loss-less to use and interchange between different color spaces, means enable the communication between various color spaces, like for instance CMYK for print and RGB for screen. Last but not least to support the needs of different workflows globally (asia, europe, america). So I'd expect the outputintent to be either the document color space or the selected export profile.

 

>> ... You mention where this profile does not appear? What PDF settings is this in relation to?

The U.S. Web ...icc appears as output intent in the PDF but not in the profile list in export settings. Excuse my unclear expression. Actually I do not want this CMYK profile appear in RGB export settings profile menu but also I don't expect it in the resulting PDF but the set RGB profile instead.

For sample under b.) in my initial post the document color space was set to RGB with sRGB... profile (s. screenhot above), the export setting, too.
I used 3 JPGs, each with embedded profile:

RGB jpg + "sRGB IEC61966-2.1"
CMYK jpg + "iso coated v2 (ECI)"
grayscale jpg + "Schwarze Druckfarbe iso coated v2 (ECI)"

 

In addition to the above post, the GRAYSCALE export color space could be linked to this topic. When I export the document as a grayscale PDF & grayscale profile, all three JPGs in the resulting PDF file are grayscale images and have the selected export grayscale profile. However, these grayscale PDF files contain no output intent and the images do not appear in black only, but unfortunately in CMYK.

If you still need my document let me know – I think you can reproduce this issues with any jpg in the mentioned color space and profile.

 

[adrianlambert]

I read this as though he's saying not that Web Coated (SWOP) v2 is the default for PDF/X-4 but the default CMYK colour profile for AP. 

[thomaso]

> but the default CMYK colour profile for AP. 

 

Nevertheless it should never occur in any document or exported file as soon the user has chosen other profiles – as I had experienced in this thread (see above), or, for instance as noticed today by Lagarto:

8 hours ago, Lagarto said:

I was confused by incorrect assignment of color intent, which when I export with default PDF/X1a:2003, PDF/X3 and PDF/X4 is for some odd reason "U.S. Web Coated (SWOP) V2" while I have ISO Coated V2 (ECI) as my Affinity CMYK default, so I do not know where Affinity Publisher gets this.

 

 

[adrianlambert]

It absolutely should not occur!