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Gimp around in 80 minutes

Transforming a Photograph to a Drawing

Because black is transparent in Screen mode (also Addition and Lighten Only) black pencil strokes drawn on a white layer will reveal the image underneath, just as if you had sketched all by hand. This is an easy way of creating convincing pencil/ink drawings from a scanned photo.

Manage without artistic plugins

There are several commercial plugins called things like charcoal, crayon or ink drawing that supposedly achieve these things. Certainly, these products can produce nice artistic outputs, but they never come close to the results you get using this method. Naturally, the quality of the final image depends a lot on the drawing in the screen layer, so this isn't an "instant artist" trick. A general advice is to reduce the number of shades in the background, otherwise too much of the underlaying image will show, and this will spoil the illusion. One way of improving coarse computer drawings is to use the Value Propagate filter and set it to more white. You can also create a crayon or charcoal look to an image by displacing or warping the pen strokes with a suitable displacement map, or just by using unusual brushes.

Instant cartoon pictures

A very simple way of creating drawings from scanned photos is of course to use one of the Edge-Detect filters. Running Sobel on a duplicate results in a transparent layer with a black outline of the image object. Having done this, it's easy to paint the underlaying layer in large clean areas, and you'll get something very similar to a picture in a comic book.

Making a pencil drawing To make the pencil drawing, a white layer was placed on a b/w photo. It was set to Screen mode, and the opacity was temporarily reduced, so that the background would be visible. The sketch was drawn with a small, sharp pencil tip, and made to follow the contours and shapes in the photo. The photo's tonal range was limited by using the Image/Posterize filter, and the sketch layer was displaced slightly with a canvas structure as map. The image was flattened and adjusted with Brightness-Contrast to get the right gray value of a pencil drawing. From pencil to ink The sepia ink drawing was created from the previous drawing (pencil). Color was adjusted with Hue-Saturation and Brightness-Contrast to a sepia-like quality, and a beige "sketch paper" layer was added in Multiply mode. The "white crayon" in the sketch paper layer was painted with the airbrush and several soft edged brushes.

Digital crayons For the crayon drawing I used coarser, rugged brushes. I also displaced the sketch layer twice to get the right scratchy crayon or charcoal look. The image was flattened and the contrast was increased with Levels. I made a duplicate layer and used the Dark 1 gradient in the Gradient editor to map to the image (Colors/Gradient Map). I put the old layer on top of it, set it to Multiply and erased everything except the contours, and parts which I wanted to keep dark (like the baby's eye and ear). In the top layer I placed the posterized photo as Darken Only, changed the color to violet, and applied some motion blur. This looks somewhat like watercolor, if it's only used in small areas of a composite image.

The Gimp User Manual
Last modified: 19 May 1998