Color Calibration

[johnny]

Hello,

I need to fully understand how are color profiles handled by XnView. I have gray gamma 1.8 and 2.2 photos and when compared to another well known color managed software and even with XnView MP colors photos do not look the same for settings that looks like similar. I suspect that there's something not properly set or something I do not understand or that some default color profiles are applied in some cases in XnView.

In a well known software, when loading a photo with a different profile compared to the work place, we are asked to choose among options : use embedded profile, convert to the working space or don't manage. With these choices I can easily do everything I want without any risk errors. I can go from a gamma 1.8 and convert to a gamma 2.2, convert a sRGB to gamma 2.2, and so on.

I cannot figure how these choices can be made with XnView (and even XnView MP).

- When "Use ICC profile from monitor (slower)" is not checked, does it mean that the photos will not be color managed ?
- If "Use ICC profile from monitor (slower)" is checked, the options defines what happens if no profile is embedded. Can I apply any profile like Grey Gamma 2.2 ?

- If the photo has an embedded profile, will any embedded profile be properly used by XnView, like Grey Gamma 2.2 ? Is there a place where I can see the active color profile for a photo shown within XnView ?

Don't you think it would be easier, in options, to pick two defaults profiles one for color and one for B&W photos and then ask what should be done when a photo has a different color profile from the 2 defaults. This way we could be sure, XnView use the right color profiles.

I could not find real complete explanations on color profiles management. I imagine I'm not the only one having hard times understanding what's going on with photo color profiles. I tried XnView MP to see if I could get consistent color management and I had the same problem : not understanding exactly understanding what profiles are used the the software for a photo.

[xnview]

Hello,
- When "Use ICC profile from monitor (slower)" is not checked, does it mean that the photos will not be color managed ?

yes, there is no color profile applied

- If "Use ICC profile from monitor (slower)" is checked, the options defines what happens if no profile is embedded. Can I apply any profile like Grey Gamma 2.2 ?

you can set a color profile in 'other'

- If the photo has an embedded profile, will any embedded profile be properly used by XnView, like Grey Gamma 2.2 ? Is there a place where I can see the active color profile for a photo shown within XnView ?

If the photo contains a color profile, it will be applied to the image...

[j7n]

Color profiles for Grayscale don't seem to be applied at all. Grayscale upconverted to RGB with works, gamma is applied and the loading speed is slower.

[xnview]

Color profiles for Grayscale don't seem to be applied at all. Grayscale upconverted to RGB with works, gamma is applied and the loading speed is slower.

could you send me a sample file?

[j7n]

Here is an example. Two RGB files, normal sRGB and Apple at 1.8, look the same. The correction works on them. The grayscale files at gamma 1.8 and dot gain 10% get darker, 2.2 is close to sGray, but still looks slightly different. This is in XnView Classic 2.50.3.

Irfan said to me that profiles for greyscale are too rarely used, and might be added later if someone else asks.

http://j7n.sytes.net/temp/j-srgbgray.zip