Unexpected color space conversion when opening an image in TIFF format

[Jean-Pierre Fleury]

Hello,

I am using Affinity Photo 2.0.4 on Windows 11 in French.

My Color management configuration looks like in the picture "AFP preferences.jpg".

My standard RGB color space is "Adobe RGB"

I didn't check the option "Convertir les fichiers ouverts en espace de travail".

I check the option "et avertir".

So I expect that Affinity Photo do not convert the color space when I open an existing file which contains a different color space than "Adobe RGB".

But when I am opening a TIFF format image that contains the sRGB color space I am surprised to find that Affinity has automatically converted the working color space to Adobe RGB without any warning. This can cause bad color conversions without the user realizing it.

What do you thing ?

Thank you in advance for your feedback.

Best regards

 

[walt.farrell]

Welcome to the Serif Affinity forums.

You mention Opening an image. But from that screenshot it appears that perhaps you were creating a panorama via File > New Panorama when this happened. If so, since that is technically a new image, perhaps it was created using your preferred color profile/space.

I never work with panoramas, so I am not sure if that is normal/expected for Affinity Photo, or not. But I wanted to mention it as a possible explanation for what you're seeing. And to clarify exactly what workflow you're using.

[Jean-Pierre Fleury]

Thank you Walt for your feedback,

My workflow is the standard workflow for opening an existing image. It looks as follow:

1. I open Affinity Photo. No document is opened. The standard "New document" dialogbox is automatically opened.
2. Because I want to open my TIFF picture I select the command "Open... Ctrl+O" in File menu. Then the "Open dialogbox" is displayed.
3. I select the TIFF file with sRGB color space
4. Affinity opens the picture. At the top of the screen is the information from my second screenshot.

 

I don't understand why panoramique is displayed at the top, but it is always the case with my french version of Affinity. In my use case i am not using the command "new panorama" of the file menu.

Thank you in advance for your feedback.

Best regards  

Edited January 29, 2023 by Jean-Pierre Fleury

[Old Bruce]

12 minutes ago, Jean-Pierre Fleury said:

I don't understand why panoramique is displayed at the top,

Perhaps because that is the name of the tool you have selected.

[walt.farrell]

Thanks, @Jean-Pierre Fleury. Can you share one of your TIFF files with us? If you can, probably best to zip it and attach the zip file to ensure the forum software doesn't interfere with it.

[Jean-Pierre Fleury]

Hello,

You will find attached my example of a TIF file generated with DxO Photolab. I checked. The problem occurs by opening this TIFF file on my computer.

Hi Old Bruce. That's right. Affinity displays "Panoramique" in the french version when the hand tool is selected.

Thank you all for your help

B22_2783_PL_AFP-Print.zip

Edited January 29, 2023 by Jean-Pierre Fleury

[walt.farrell]

Thanks.

I don't see anything wrong with that image, and I can confirm I see the same behavior for that one on my system. (And some other images I've tried.)

So it appears that Photo 2 2.0.4 on Windows is always converting to the working space, even for images with color spaces specified in their metadata.

[lepr]

50 minutes ago, Jean-Pierre Fleury said:

Hello,

You will find attached my example of a TIF file generated with DxO Photolab. I checked. The problem occurs by opening this TIFF file on my computer.

Hi Old Bruce. That's right. Affinity displays "Panoramique" in the french version when the hand tool is selected.

Thank you all for your help

B22_2783_PL_AFP-Print.zip 5.38 MB · 1 download

 

The TIFF contains two versions of the image:

• 1200 x 800 px, 16 bits per channel, sRGB
• 300 x 200 px, 8 bits per channel, no profile

Looks like Affinity loads the first image, but regards it as having no profile, and so Affinity assigns your default profile for 8/16 bpc RGB documents - AdobeRGB in your case.

When AdobeRGB profile is assigned to an sRGB image, the image will appear oversaturated. You can assign sRGB profile to the document to get it back to where it should be.

Important: I deliberately wrote "assigns", "assigned" and "assign" rather than "converts", "converted" and "convert". There is a significant difference between assigning and converting.

[Jean-Pierre Fleury]

Thanks very much Walt,

From my point of view it is a bug which must be corrected. This is not blocking my work, but it increase the risk of uncrotolled color conversion from one to an other colorspace. 

Regards 

[walt.farrell]

6 minutes ago, ,,, said:

Looks like Affinity loads the first image, but regards it as having no profile, and so Affinity assigns your default profile for 8/16 bpc RGB documents - AdobeRGB in your case.

I can reproduce this, though, with several TIFF and JPG images that I have in my collection. They are all sRGB, but if I set my working space color to ROMM RGB in Preferences, Photo 2 loads them as ROMM RGB rather than sRGB.

[Jean-Pierre Fleury]

I just see your last explanations.

I suppose that the second picture is a thumnail used by the OS and other software. 

Thank you very much for your help.