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 |
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 > |
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