Using Photoshop I have converted a photograph into a sketch/line drawing, I achieved this in photoshop by:
- Making image greyscale
- Duplicating image then inverting it
- Applying a color(colour) dodge
- Applying a gaussian blur (level 8)
Here is the effect, as you can see there are undesired effects on the cats face, where the fur is dark, I've discovered that because the area is not all pure black, and different variations of black.
How can I fix the image before applying the effects to prevent such artefacts from accruing?