[ImageJ-devel] ImageJ 2.0.0-beta1 - Brightness and Contrast dialog

Gabriel Landini G.Landini at bham.ac.uk
Thu Apr 12 11:38:51 CDT 2012

More on Brightness and Contrast dialog:

1. I can't do anything else until I close the dialog. For example, IJ2 does 
not report pixel the values under the cursor until the brightness dialog is 
closed. Is that how it is planned to work?

2. Dialog needs "reset" and "apply" buttons.

3. Minimum and maximum return fractional values for an 8 bit LUT. Is that 

4. Are the Brightness and Contrast values (0-100?) the best scale resolution 
to use?. I think that having 100 units controlling LUTs with 256 values at 
least for 8 bit images will create unnecessary hassle (like the fractional 
values mentioned above). I can't see any advantage on 0-100 vs 0-255 (but 
maybe there is some reason?).

5, Compare Contrast in IJ1 with IJ2. In IJ2 the contrast does not respect the 
brightness, as (without any brightness tweaking) the contrast should narrow 
the LUT to 127 or so. Currently IJ2 at 100 setting of contrast has a minimum 
of 0 and a maximum of 4.67 (?). 
I think contrast should control the width of the LUT from both sides, while 
keeping it centred. Currently it affects the max value and as a consequence it 
changes both the width and the position of the lut. So "Contrast" behaves same 
the "Maximum" slider of IJ1,

6. Maybe Maximum and Minimum would be more useful having sliders too instead 
of number boxes.



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