Posted by
Michael Schmid on
Nov 30, 2020; 7:04pm
URL: http://imagej.273.s1.nabble.com/bug-with-Brightness-Contrast-tp5024248p5024257.html
Hi Wayne, Michael,
this is nothing that I have seen with B&C (neither on small nor on large
images), but I do see a related problem with Image>Adjust>Color Balance
(It is there since a few months, I don't remember when I've noticed it
first). Maybe the two issues have the same root.
Color Balance problem:
Open Clown Sample
Adjust color balance of red channel
Click "Apply"
Message: "Warning, pixel values will change if you click ok"
Click ok
Switch to green channel on Color Balance
and the image has reverted.
ImageJ 1.53g57; Java 1.8.0_112 [64-bit]; Linux 4.4.0-194-generic
With B&C, as long as no other image is selected, the "Auto", "Set" and
"Reset" buttons also revert to the original settings after "Apply", and
also moving the sliders does not care about the previous 'Apply'; to me
this is not a bug but rather nice behavior. It may be an issue if one
wants to limit the values like this, hovever:
If I set the range to 0-127 to limit the max to 127, "apply", and then
change to 0-512, then we are back to the original image.
But this operation would be better done by Process>Math>Max anyhow.
Best,
Michael (one of the many :-)
________________________________________________________________
On 30.11.20 19:27, Wayne Rasband wrote:
>> On Nov 29, 2020, at 11:29 PM, Cammer, Michael <
[hidden email]> wrote:
>>
>> I have been having problems with B&C for some time and would appreciate help.
>>
>>
>> When I adjust the contrast and hit apply, usually the contrast is not applied.
>
> I am not able to reproduce this problem using ImageJ 1.53g and Java 1.8.0_172 on MacOS and Windows.
>
> -wayne
>
>
>> However, if I adjust the contrast and then duplicate the image, the resulting image does have the contrast applied.
>>
>>
>> I have posted examples.
>>
>> Illustration of problem:
>>
http://microscopynotes.com/temp/00_bandc_notapplied.png>>
>>
>> Example image that does not work:
>>
http://microscopynotes.com/temp/00_bandc_data.jpg>>
>> This has been a problem for at least two months and I checked it tonight with ImageJ 1.53g56 Java 1.8.0_172 Windows 10.
>>
>> Any help appreciated.
>>
>> Best regards-
>>
>>
>>
>> Michael Cammer, Sr Research Scientist, DART Microscopy Laboratory
>>
>> NYU Langone Health, 540 First Avenue, SK2 Microscopy Suite, New York, NY 10016
>>
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