Reference photos for street rider by Hughe is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
Based on a work at http://wp.me/p1fjgj-1vI.
Permissions beyond the scope of this license may be available at https://butterflyofdream.wordpress.com/.
Image process steps
Motorcycle: 2006 Yamaha R1
Camera: GoPro Hero HD2
Shooting location: A city and countryside, South Korea
Software: Debian GNU/Linux Wheezy, VLC Media player, GIMP 2.8, ImageMagick
Make sketch effect in GIMP 2.8.
Load a color image file.
Apply [Duplicate Layer] Twice.
Turn off the top most layer by clicking the eye icon.
Select the second layer.
Colors – Invert.
Filters – Blur – Gaussian Blur: set value from five to ten.
Set the layer opacity to 50 percent.
Merge down the layer.
Colors – Levels: Set White to 127, Black to between 90 and 100.
Colors – Desaturate: It removes colors.
Select the top most layer and turn on the eye icon.
Colors – Thresholds
Set the layer opacity to 50 or whatever value you like.
File Export (Ctrl – Shift – E)