Howto convert photos to line drawing with GIMP

GIMP provides a large tool set to edit photos. This software is provided with GNU License and is available to use on Linux and MS Windows computers.

Artistic look from photos can be created with a few steps in GIMP 2.8.8.

Start GIMP and open the photo (which is in colour).

Step 1: Select the photo.
From the main menubar, click Select ->All or press "Ctrl+A"

Moving dots/dashes should be around the photo.

Step 2: Remove colour from the photo.

Click the menu Colors ->Desaturate... and choose a shade of gray based on Lightness or Luminosity or Average. Click "OK"

Alternative method:
Click the menu Colors ->Hue-Saturation... and slide Saturation value all the way to left or -100.

Step 3: Strip gray tones

Click the menu Filters ->Edge-Detect ->Difference of Gaussians...
Default checks the boxes Normalize and Invert. Radius 1 value is 3.0 and Radius 2 is 1.0.

Note: At this point if it results in a blank image, remove the Alpha channel

Step 4: Raise the lines

Click the menu Colors ->Brightness-Contrast...

Increase brightness value and reduce contrast value until image appears. Click "OK"

Step 5: Enhance the light lines

Click the menu Colors ->Levels... and click "Auto".
In the graph like "Input Levels", slide the triangle till to left until the desired tone. Click "OK"

Done.