Posted by
Wayne Rasband on
Oct 30, 2008; 7:40pm
URL: http://imagej.273.s1.nabble.com/CompositeImage-color-range-behavior-tp3694614p3694615.html
The Image>Adjust>Color Balance tool should work better with composite
color images in the 1.42a daily build. There are four composite color
images in the File>Open Samples menu: "Fluorescent Cells", "HeLa
Cells", "Neuron" and "Organ of Corti".
-wayne
On Oct 29, 2008, at 1:30 PM, Curtis Rueden wrote:
> Hi,
>
> I have noticed that CompositeImages behave rather non-intuitively in
> some
> ways, and was wondering if the behavior I'm seeing is a bug or a
> feature.
>
> 1. File > Open Samples > HeLa Cells
> 2. Image > Adjust > Color Balance
>
> At this point, just changing between "Red", "Green", "Blue" and "All"
> in the
> dropdown box causes some additional autoscaling to take place,
> changing the
> visual. It seems odd to me that just changing which color table I'm
> looking
> at should alter the image's color scaling.
>
> 3. Select "All" from the dropdown.
> 4. Set button, Min -> 0, Max -> 1000, OK.
>
> The image gets more washed out at this point, as I would expect, but
> changing channels between Red, Green and Blue resets the color scale
> channel
> by channel -- as does moving the channel slider in the image window,
> which
> seems linked to the dropdown and I'm guessing is intended to be
> equivalent.
>
> Alternately, selecting the Red channel, clicking Set, entering min ->
> 0, max
> -> 1000, and checking "Propagate to all 3 channels", I would expect it
> to do
> the same thing as above (choosing "All" without checking that box),
> but the
> final visual looks different. It appears that ImageJ visibly steps
> across
> each channel applying the settings, which get instantly overwritten
> because
> moving between the channels invokes the autoscaling procedure.
>
> Personally, what makes sense to me would be for toggling between
> channels of
> the CompositeImage to never affect the visual appearance or alter the
> color
> scaling. As things stand, it is very easy to hose up your color
> ranges, and
> the "Propagate to all X channels" checkbox seems largely ineffective.
>
> Thanks,
> Curtis
>