Jump to content
tariq

Photo colour profile bug? incl what fixed it for me

Recommended Posts

I found a bug and a workaround regarding colour profiles.

 

On the latest MacOS 10.13.2 and latest Affinity Photo 1.6.6 (from the App Store), with an external NEC EA244UHD monitor connected over DisplayPort to a 2015 MBP 15" with Intel graphics - here's how I recreated the bug:

 

  • take a screenshot using shift-cmd-3
  • the screenshot for me was of a web browser page with an image created programmatically, where the colours are chosen precisely by me, for example a green is RGB (0, 200, 0).
  • open the screenshot PNG with the preview (press space) or the Preview application (Open) - shows the correct shade of green.
  • open the same screenshot PNG in Affinity Photo and the green shade is different - lighter and more yellow
  • both Preview and AP shows the colour profile name as Display

 

I searched the web incl. these forums showed no obvious solution, but some pointed to a bug in how AP selected a profile to apply based incorrectly on the ASCII name only, which can mean the wrong one is selected. 

 

Here's what I did to fix the problem. 

 

  • using Spectraview and an X-rite i1 Display pro hardware device calibrate the monitor, I generated a new ICC profile
  • now both Preview and AP show the colours correctly when new screenshots are taken, as the PNG files now contain the new ICC profile

 

I'm not an expert but I suspect the online suggestions that Affinity Photo was incorrectly choosing the profile to profile based on ASCII vs other/unicode/ID name makes sense. 

This experiment which creates a different profile name, which here is "EA244UHD 47100533TB 2017-12-13 00-25 D65 2.20".

 

I haven't tested this problem using the MacBook display with no external display attached.

Share this post


Link to post
Share on other sites

Hi tariq

 

Are you able to attach he image that showed the issue so we can look into exactly what you are seeing?

 

It seems like it might be more the conversion from the internal profile to the monitor profile which is why calibrating the monitor may have solved the issue

 

cheers


Serif Europe Ltd - Check the latest news at www.affinity.serif.com

Share this post


Link to post
Share on other sites

Attached are 2 screenshots taken using shift-cmd-3 and cropped using the Preview tool and saved.

 

They look very similar with Preview. But drastically different in Affinity Photo.

 

I didn't crop and save with AP because then the two PNGs permanently look different in any viewer.

 

Regardless of conversion pipelines .. Preview seems to do it correctly and AP not .. but do explain it to me if I'm wrong.

Screen Shot 2017-12-15 at 00.18.35.png

Screen Shot 2017-12-15 at 00.18.32.png

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×