Created attachment 119399 [details] Screenshot of the issue. Note the default linear/uncorrected settings. SUMMARY Histogram initializes greyer than white. STEPS TO REPRODUCE 1. Open ImageEditor 2. Open a picture 3. Select the curve correction (Histogram tool) 4. Keep the default parameters OBSERVED RESULT The top histogram is compressed by 1/3 to darker levels than white. And the previewed picture is darker then normal (even if I reset to default histogram settings) EXPECTED RESULT With default curves, the top histogram should be identical to the bottom one, and picture should be as bright as the original. SOFTWARE/OS VERSIONS Windows: 10 Family ADDITIONAL INFORMATION
Adding missing steps : 4.1 Select the white drop, click on a whitish area. The picture & histogram is darker than expected. 4.2 Reinitiliase using the "Reset" button close to the histogram. The correction do NOT reinitialise totally. It keeps darker than expected. Workaround : Reinitialise using the "Default" bottom button close to the Ok/Cancel buttons. Then it works. So the issue is maybe more on the "White Drop", in fact...
This problem should be resolved in digiKam-6.1.0. The reset function resets only the current channel. We now have the option to choose Reset and Reset All. Could you please test it with the pre-release version: https://files.kde.org/digikam/ Maik
No. The image sound like corrected as the gamma settings. Strange. Press Reset/all button to see if the fix the problem. Gilles Caulier
The issue is still there with 6.2.0 Please find attached another screen capture with - Dark drop pointed in the girl backpack. Expected to be full black after curve correction, but result is lighter grey. - White drop pointed to the sky. Expected to be full white after correction, but result is darker grey. - Moreover, the top histogram is too much compressed instead of being full width. I think that the drops don't work as expected.
Created attachment 122106 [details] Curve Black White Drop not working
Maybe i should split this ticket, as now the initialisation is OK but the issue is on the "Drops". Please advise and i can split the ticket if necessary.
Closing this one (as histogram now initialize OK) and creating a new one for bad Drops behaviour...