The wave of the tutorials for Gimp today, with a simple process but we'll see how effective “give” of warm colors to any photo with the instrument “Gradient Map“.
The knowledge base for this tutorial are minimal, it is enough to know the use of mode of the layer stacking.
Personally I think are most appropriate for this tutorial with pictures very sharp reflexes, use a photo without reflections is lawful, but the result will surely be different. We will use the following picture from Flickr.
First duplicate the main level, it desaturiamo (“Colors” – “Desaturation“) and rename “gradient map“.
Now we select the red how to color in first floor, and yellow as color background. The colors I used are “#ff0000” and “#ffe400“.
After you have selected the colors we are going to apply the “Gradient Map“. “Colors” – “Map” – “Gradient Map” and we set the mode the level of “Overlying“.
Lastly create a new layer, yellow “#ffe400” and we set the mode “Overlying” and opacity “50%“.
And the end result you've already seen.