Change blackest point to pure black and whitest to pure white

[Ofnuts]

(03-19-2018, 08:37 PM)Julienroy Wrote: Hello,

Quick question, I'd like to make the black to white range broader by changing the blackest point of my picture (let's say very dark grey) to pure black (#000000) and the whitest point (very pale grey) to pure white (#ffffff). The rest of shades should follow accordingly.

I've been messing with the curves in "colors" with no results. I know it's doable in Photoshop, I'd like to use the same function in gimp.

Thanks in advance,
Julien

Curves should have worked if used properly. So will Levels (drag the left and right handles in "Input levels" to the values of the black and white points).