GIMP Tutorial: Artsy Sketchy Header

I was messing with some various GIMP effects the other day while working on a new design and I came up with a very good sketch effect for the photograph I was using. This is the image I started with:

I am using small images in this tutorial but the original image is larger (about 1200×700) and I recommend starting with a high resolution for this.

Step 1 was to apply the Van Gogh filter (Filters->Map->Van Gogh(LIC)) with the standard settings and save the result for later. This filter creates a blurry, oil-paint-like result:

Step 2 was to return to the original image and apply the Photocopy filter (Filters->Artistic->Photocopy) with the following settings: mask radius 10, sharpness 1, percent black 0.1, percent white 0.6. The result is a grainy black and white image:

Step 3 was to use the Threshold dialog (Layer->Colors->Threshold) to reduce the image to just black and white. There are no numbers for Threshold but here is how far I dragged the slider:

The result is a pure black and white shadow of the original image:

If there are anny errant splotches of black in the image (as in, black spots that are not part of the tower), erase them now with a white paintbrush. The next step is to use “Select by Color” (Select->By Color) and click on any white area with these settings: antialiasing, feather edges 2, threshold 10. After selecting all the white, I deleted it to get the black isolated over a transparent background:

Finally, I took this result, copied it (Edit->Copy Visible), and pasted it over the original Van Gogh filtered image:

Presto! The result is an artsy, sketchy looking photo-manipulation, and exactly the effect I was going for. It looks better at full size, but until I have the completed design up you will just have to take my word for it.