Here’s my workflow:
- Open your image (it works best on moderate-sized images of about 1200 pixels)
- Load G’MIC, set the Output mode to “New active layer(s)”, and Output messages to “Verbose (layer name)”
- Apply the Testing/Photocomix/Photocomix smoothing filter, changing only Amplitude to 10 (works also with Repair/Smooth [diffusion])
- Set the newly created layer mode to “Grain extract”
- Right click on this layer, click on “New from Visible”
- Set this new layer (named “Visible” mode to “Grain merge”, and set the layer just below (named “[G’MIC] Photocomix Smooth…”) back to "Normal"
Note: the “Visible” layer now contains the details/grain of the original image, which you will put up later, leave it there for now.
- in G’MIC again, Apply the Details/Simple local contrast filter, change:
-Edge sensitivity to 25
-Iterations to 1
-Paint effect to 50
-Post-gamma to 1.20
- Now apply the Artistic/Graphic novel filter, checking the Skip this step checkbox for Apply Local Normalization, and changing:
-Pencil size to 1
-Pencil amplitude to 100-200
-Pencil smoother sharpness/edge protection/smoothness to 0
-Boost Merging Options Mixer to soft light
-Painter’s touch sharpness to 1.26
-Painter’s edge protection flow to 0.37
-Painter’s smoothness to 1.05
and click OK to close G’MIC
- Finally, click on the layer named “Visible”, and drag it to the top of the layer stack to bring the detail back. You can even duplicate this layer to increase the detail level, and adjust its opacity.
Of course you can play with the different filters’ parameters, with the opacity of the “[G’MIC] Graphic novel…” layer, apply a contrast curve to taste.
I find this type of effect to work really great on portaits, models, cars…