brucewells wrote:
Curves are just one single edit that can be done to an image, usually to adjust the contrast of the image. Many, if not most, editing programs provide the functionality. The "free" stuff will always have some method to extract your money (ads, time constraints, etc.).
Gimp is the GNU Image Processing program. The Free Software Foundation is a bunch of very talented software developers who believe that people shouldn't have to pay for software ..... most of them develop things like this just for the joy of it .... that is why their icon features the cartoon character that occasionally puts off too-serious photographers. In this case, there are no intentional "gotcha's" - no slowdown, no advertising {if you get it straight from them}, etc.