To create a vectorized sketch from a photograph for a brochure or for use as a logo:

  1. Open the photograph in Gimp and create a sketch of it as described in the following. Please understand all values as suggestions only. Feel free to experiment. 😊
  2. Image/Scale image (150–300 dpi)
  3. Ctrl-Shift-D (duplicates the layer)
  4. Filters/Blur/Gaussian Blur (typically 2% of the dimension of the image)
  5. Colors/Invert
  6. set opacity to 50%
  7. right-click on layer, Merge Down
  8. Colors/Levels, set to 100–155
  9. Colors/Desaturate
  10. Colors/Levels, set max to 128, play with Gamma
  11. Save. A script called quick-sketch is available, but the above gives you a higher degree of control.
  12. To vectorize this sketch, open it in inkscape via the File/Import feature. Then:
  13. resize page to selection via Ctrl-Shift-D (Document properties)
  14. Shift-Alt-B (Trace Bitmap)
  15. Mode: Grays, check stack scans
  16. Options: suppress speckles 25, smooth corners 1, optimize paths 5.

Here's an example created by the above procedure:


PS: If you don't see an image above, try another browser. Opera 11, IE 9 and all current Webkit incarnations (Chromium, Safari, Konqueror, Uzbl, Midori …) support svg as image format. Firefox will support it in the soon-to-be-released version 4.