I was doing a puzzle, initially it was not my intention but, you know, you start a puzzle to test something you are programming and then you can’t leave it incomplete as you see pieces that match or matches that claim a piece fit :-)
A certain zone of the puzzle I was working was quite dark and the Sun was shining through the window so it was difficult to see the details in that part of the image. It would be nice to be able to make the image more clear while working that specific region! so there we go…. we have a new version with that ability.
Look these two captures, first the original and next, the temporarily altered. In this case, the brightness was raised and the contrast lowered in order to squeeze the detail in the dark zones.
These settings are located in the same option to resize the puzzle, accessed by pressing the I key while a puzzle is loaded (in the menu it appears as "Resize / Brightness"). To access this feature you need to have installed version 5.8.5, downloadable here
Each image reacts quite differently depending on many factors but hopefully, this may help to adapt it to your needs and taste in case you need it. Play with it and you have always the Reset button when things are too messy.