Compare mode sometimes alters image colors in A/B view

[lphilpot]

Windows 11 Home
XnView MP 1.5.5

(Apologies in advance if this is a long or verbose, but I'm trying to be accurate.)

I've discovered an apparent inconsistency in XnView's Compare Mode. Since there are many ways to "go wrong" with color fidelity on a computer, let me answer a few potential questions first:

• My computer is color-managed and I have a system-defined display profile. XnView is configured to use that profile.

• I've taken screen captures to illustrate what I'm seeing, but they're all taken on the same monitor, using the same software* and of a single XnView instance. So there should be no differences due to device, calibration, etc. Even if there was any variation (outside XnView's control) it would still be relatively the same to XnView, so to speak.

* The screen capture software is Greenshot. I specifically used a third-party utility rather than XnView's built-in capture capability, in order to be more objective in this context.

So, I have three images (attached as 1.jpg, 2.jpg and 3.jpg if you want to test on your system). Here are the thumbnails:

thumbs.png (46.64 KiB) Viewed 1395 times

1 is the original, 2 is a identical copy of the original (copy / paste) and 3 is an inverted (by XnView) but otherwise identical copy of the original. No other differences.

If I compare 1 and 2 in either Normal or A/B view of Compare mode they look exactly the same, as expected:

OK, so far so good. If I compare 1 and 3 in Normal view it also looks correct, as expected:

But if I compare 1 and 3 in A/B view the color saturation of 3 is altered:

Look at the difference of the (inverted) sky of 3 in Normal view vs. A/B view. Same image in both cases.

What I don't understand is why it happens only in A/B view with 3. If there's a issue with A/B view you would expect it to show up every time A/B view was used, but that's apparently not true. Comparing 1 and 2 is good no matter the view, while comparing 1 and 3 is good only in Normal.

And by the way it works properly in Tab view as well for all three images.

Again, even if (in an overall sense) the color on my system isn't technically perfect, it should be entirely consistent within the scope of this context. It certainly shouldn't apparently change between Normal view and A/B views.

Thanks.

.

[xnview]

Thanks to your detailed description I can reproduce the problem.

[xnview]

This problem is supposed to be fixed in XnView MP 1.6.0. Please check and confirm the bug fix here.

[lphilpot]

Looks good now to me, thanks!