Open GIMP and select an appropriate file for the effect. I find file choice to be the best part. I tried doing this with flowers and buildings, and the filter added absulotly nothing to the image. You also have to prefer an image that will turn out well. The highest ambition in carrying out this is to support a print on the best paper that you can buy, glossy and frame. These effects look nice on a laptop screen, but to build a Van Gogh, even a bogus one, you need to have the interaction of ink or toner on paper. Once you have chosen an portrait. choose the FILTERS tab and the Van Gogh Filter from the ARTISTIC tab.

2 Applet Panel
As you can see, this applet contains a lot of controls, and as a result, choices you can have. It requires quite a bit of experimentation. Start by using the DERIVATIVE controller and convolve with the SOURCE IMAGE. The gradiant will produce an effect that changes from top to bottom and will barely be usable for some images. White noise will work only on few images as well, and create a brighter result. For this example I will set the sliders and not adapt them, but modify only the EFFECT Channel. When you work with the applet you can use the sliders to tune your Van Gogh.

The author is the owner of Gaya art prints and an art guide.
You can find a lot more informations on my Van Gogh gallery