BUG: Mapping of channels

[pwalczysko]

Found during testing ​https://github.com/openmicroscopy/openmicroscopy/pull/1652.
When mapping the image pixel values for display in the Rendering panel, the channels do not seem to be connected to the selected mapping algorithm (for example when I select red channel and change the mapping from linear to logarithmic, the display of the image changes as expected. But when I switch the channel to green, the mapping stays apparently the same (logarithmic), but in fact I am viewing the red channel in logarithmic scale - there seem to be no correspondence. When I change back to "linear", the new choice does not seem to be respected. Not sure what the intended behaviour of this feature was, but at present it seems to be not very useful for following workflow:

• look for the values which are hard to see using different mapping methods
• change the mapping for red channel and check whether you can see something in the image
• repeat the mapping change also for green channel, blue channel and so on, checking every time how the display changes

See also attached movie.

This strange behaviour is not FLIM-images specific - it is visible also on .dv images.

[pwalczysko]

This would be fair enough, but there is another, I guess strictly UI-side problem, which makes the behaviour very confusing for the user.

I mean: Even when the mapping is global for all the channels, the only place to switch the mapping and get the update is to be on the Red (=first) channel. If you try to update the global mapping when being on the green channels, although the menu apparently allows you to do so, in fact you are doing nothing.

In the attached movie, I was on Red channel, changed mapping from linear to log, then went to Green channel, changed mapping back. Not only I am still being shown the Red channel, but also I am still seeing the Red channel in Log mapping, although the menu clearly says Linear. The only way to get really back to linear is to go to Red channel and change to Log, then back to Linear - only then the display of the image changes to black (as it was in the beginning).

[jburel]

see ​https://github.com/openmicroscopy/openmicroscopy/pull/1726

[Jean-Marie Burel <j.burel@…>]

(In [8edef884869af69019b0150044346b2e967adaf3/ome.git] on branch develop) Fix map and coefficient selection. see #11633