I use this kind of effect all over my PowerPoint slides. I figure I share this with everyone…. Knowledge is for sharing!!
1) Open your image using GIMP
2) Select the “Colors->Curves…” from the pull down menu
3) Adjust the colour curves by dragging the line from the x=0 and y=0 position.
Before colour curve adjustment
After colour curve adjustment
4) You can see that it is already starting to take shape. Drag the same line again to get the setting that you like. Next we will be saing it as a usable picture file.
5) From the pull down menu, export to an images file by selecting File – > Export As… And then, give the image a name and click on “Export” button.
Note : The setting for the colour curve for my picture was 65=value, 86=red, 22=blue, 47=green. Note that these colour curves combination might not apply to the photo you are trying to manipulate. You will have to use your own judgement to get the right combination for your photo.
These are the before and after pictures of my photo.