Ticket #1100 (new defect) — at Initial Version

Opened 8 years ago

Last modified 7 years ago

Brightness and Contrast dialog issues 2

Reported by: bdezonia Owned by: curtis
Priority: minor Milestone: imagej2-b8-analysis
Component: Display API Version: 2.0.0-beta6
Severity: serious Keywords:
Cc: G.Landini@…, Michael.Cammer@… Blocked By:


In the imagej devel maling list Gabriel Landini noted the following issues with the Brightness/Contrast plugin:

  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?

  1. Dialog needs "reset" and "apply" buttons.
  1. Minimum and maximum return fractional values for an 8 bit LUT. Is that


  1. 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,

  1. Maybe Maximum and Minimum would be more useful having sliders too instead

of number boxes.

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