Color change like night mode

[Defacta]

Hello,

I am stuck on a particular problem. I am under Windows and on night I use SunsetScreen to switch my screen to the night mode.

And I have images that I prefer when this tool is running (with default values (Sunset colour (K) 4100)  but I can't reproduce this color change on Gimp.

I know the default tool of Gimp: Colors -> Color Temperature but I just can't reproduce the same result of the tool Sunset colour. Or the same result of my iPhone night mode.

Would you have an idea?

Thanks for any help,
Vincent.

[rich2005]

Welcome to gimp-forum.net.

Quote:...And I have images that I prefer when this tool is running (with default values (Sunset colour (K) 4100) but I can't reproduce this color change on Gimp.

Well, that filled in an hour without any definite result. I tried 'Sunset' in a Windows VM but being a VM does not affect the display, however can see the 'Sunset' settings.



As well as temperature there are equivalent hue and saturation settings. Problem there is the differing scales for Hue 0 - 360 deg with Gimp using -180 to +180 (and most other graphics programs )

There is an online site that will do a hue adjustment 0 - 360 http://pinetools.com/adjust-hue-image and comparing results, looks like the value slots straight into Gimp.



I get this as the adjustment in Gimp, but I do not believe it. Is it possible to take a screenshot with 'Sunset' running? Might not be. If you can, post a before/after, or you can always use your judgement for a match.

[Defacta]

Hello rich2005,

Ok, I have done some pictures with my iPhone :

1/ The original:


https://i.imgur.com/gCubR3u.jpg

2/ The result with SunsetScreen:

https://i.imgur.com/qMwmevd.jpg

3/ What I get with Colors -> Color Temperature :

https://i.imgur.com/5aPph9C.jpg

Original file: https://i.imgur.com/n6vrJ4F.jpg

I couldn't do anything good with Hue-Saturation and http://pinetools.com/adjust-hue-image doesn't do anything to the file.

Thanks for your help,
Vincent.

[rich2005]

I can not get an exact match but the daytime colour temp + the nighttime colour temp round about the 10000 mark is not far away.



Best I can do easily, maybe someone will come up with a better idea.

[Defacta]

The problem with Gimp Color Temperature is that it increases the contrast and areas become too white for example.
The effect with SunsetScreen is softer, more yellow with a warmer color result.

[rich2005]

Guarantee that the same image on your computer looks nothing like the same image on my computer.

However, you could try the gmic gimp plugin from http://www.gmic.eu

The color temperature filter I thought made the daylight version a little too warm
example: https://i.imgur.com/wVtchg6.jpg wrong one https://i.imgur.com/f5zOgmt.jpg
A setting of about 8. Worth a try

[Defacta]

Yes, the screens display the same image differently. But I look for the result of SunsetScreen on my HP Pavillon 23cw screen or on my Lenovo Yoga 720 Laptop Screen not on someone else screen.
And I can not do it when there are Color temperature plugins.
I tried also the 2 GMIC plugins "Color temperature" and "Temperature balance" and none of them let me get the same effect of SunsetScreen.
I speak about SunsetScreen, but it's the same of Windows 10 "Night light settings". Can't find how to get this result.
So I tried also with a semi-transparent (5%) yellow layer on top of the image but with no success. Maybe the yellow color chosen was not the right one.

I have realised another version of the woman face in the skies:



And I really prefer the version with SunsetScreen running.

[rich2005]

Yeah, difficult to make comparisons. I have the screen brightness set way down, so what I see, more accurately reproduces a photo, when I print it. Not guaranteed to see what you see.

Quote:..So I tried also with a semi-transparent (5%) yellow layer on top of the image but with no success. Maybe the yellow color chosen was not the right one..

I tried that yesterday as well, worth pursuing but not easy to match both the darkened sky with the skin tones. However, fill a layer with a light skin tone and put the layer in Multiply mode.
It is going to be In the eye of the beholder screenshot https://i.imgur.com/HTezlPb.jpg