Here is a step-by-step description of how I created the picture above.
- Start by opening a good photo in Pixelmator. Your subject should be well lit, and the background as simple as possible. I used a photo of My Hesser, from a studio photo session awhile ago.
- Duplicate the photo layer. This way, you can easily go back to the original if you need to.
- Turn off the original layer, so it won't show.
- Select the layer you just duplicated. It would not do to work on the wrong layer. :-)
- Select the parts of the photo you want to turn into a drawing. It is usually a good idea to use Edit->Refine Selection... to fine tune the selection.
- Invert the selection, so that the parts you want to use are protected from editing.
- Use the Eraser tool to erase everything that is not protected. This will leave you with a transparent background.
- Desaturate the photo. Pixelmator has a filter for this.
- Duplicate the layer with the desaturated photo.
- Invert the layer you just created. Yep, there is a filter for this too.
- Change the blend mode of the inverted layer to Color Dodge. The photo should go white. Don't worry, we'll bring the picture back in a moment.
- Use the Gaussian Blur filter on the inverted layer. The radius should be about 45 pixels. Now you should see the picture, looking like a drawing.
- Group the two top layers.
- Duplicate the group. This is just so you can go back to an earlier stage if necessary.
- Merge the group.
- Apply a Level filter to get look you want.