Tools:
Gimp 2.8 or 2.10
G'mic 2.3 or 2.4
Selective Color Blur 0.6.2

Preparation

This workflow yields best results with similar images than the Black Widow example.
Fantasy/superhero costumes, leather, PVC etc.
It's not aiming to be a cartoon style, but more like game cover art images and similar stuff.
I've attached the .xcf file if you want to check it out, it includes the layers after each step.
But please test with some other image.

Create a transparent png version of your model.
Or alternatively make sure it has perfectly pure white background.
The tone mapping setting I'll be using will otherwise
boost the jpg artifacts or the pixels that even slightly
differ from white, near the edges.

Original



Having the png done, create new white layer below and merge the png down.
Launch G'mic.

Step 1: Details/Mighty Details. These are default settings
Amplitude: 25
Details amount 1
Details Scale: 25
Details Smoothness: 1
Channel(s): YCbCr [luminance]

Click Apply.

Step 2: Details/Tone Mapping [fast].
Radius: 0,70
Power: 0,80
Channel(s): Linear RGB [all]

Click Apply.

Step 3: Artistic/Graphic Boost. (None of the options are skipped.)

Unsharp Mask Controls: Radius 16, Darken 0,82

BW_Pencil Controls: Pencil Size: 0,80, Pencil Amplitude 162

Activate "Pencil Smoother" (yes)
Pencil Smoother Sharpness 1,50
Pencil Smoother Edge Protection 0,30
Pencil Smoother Smoothness 7,00

Merging Options, SWAP Layers (yes)
Merging Option: Hard Light
Opacity 1, Intensity 1.

Add Painter's Touch (yes)
Painter's Touch Sharpness 1,40
Painter's Edge Protection Flow 0,24
Painter's Smoothness 3,00
Click OK.

Filters/Blur/Selective Color Blur
Cartoonize, Radius 5, Iterations 5.
Color treshold 0,020, Value treshold 0,2.
Saturation 1,45-1,80 (depending how colorful you want to go, used 1,75), strictness 3.
Soft Cleaning on.
Click OK.

At this point, if you zoom near the edges there will be small leftovers here and there around the edges.
It's imperceptible at 1:1, you can clean it with small white brush.
Once done, duplicate the result. This last step is additional, to create the edges.
I suggest resizing all layers to image size prior to this step, or they may move on the canvas.

Launch G'mic again.
Testing/Jayprich/JPR line edges.
Angles per quadrant 8, Blurring 3, Gradient Threshold 24, Anti-Alias on.
Click OK.

Activate the resulted layer on top.
Color/Color to alpha. White is default, so you only need to click OK.
The JPR line edges effect will leave 1px black frame around the image,
which we can fix from selection menu.
Select all, shrink 1. Image/crop to selection.
Or you could make some fancy frame on top.
Happy gimping and merry Xmas to all CimpChat folks!

Final

That's cool!

The effect is very nice, here is my try.
However, I didn't understand the selective blur part. The Cartoonizer is another filter? Because my Selective Color Blur didn't had all these options.
I wanted to try a old comic feel, so I duplicated the result, applied Distort/Newsprint and made the layer 40% opacity on normal mode (unintentionally, before I uploaded I clicked this new layer with the Color to Alpha filter active and liked the result).

You can download Colorblur 0.6.2, or "selective color blur" like the execution window title says from this thread
Here is Colorblur 0.6.2 compiled by by Samj, post #7.

https://gimpchat.com/viewtopic.php?f=7&t=6426

Sources:

https://code.google.com/archive/p/selec ... /downloads

It has all the options I mentioned in the plugin window:



It's not same as Cartoonizer plugin (Color reducer and cartoonizer 0.8.5). That's nice too but I haven't used it much.
I've changed the workflow little because I made the first one with Gimp 2.8 on Windows.
2.10 has good high pass filter with new lineart option that can be used to create very nice and sharp edges.

Nidhogg,in your link, it's Color Blur 0.3.8 ?

I found color blur 0.6.2 for download on samj's website:
https://samjcreations.blogspot.com/2018/05/filtres-anciens-pour-gimp-210-64-bits.html
But in the README file, for the installation it does not seem possible with Windows because it is written:
For WINDOWS and others:
I'm not able to compile it for windows, but visit this page and search within the discussion: http://registry.gimp.org/node/25801
or visit gimpchat.com website

That colorblur plugin is ancient. I have tried compiling it for linux in the past but the code needs a re-write for modern compiler never mind a modern Gimp. However samj's executable does work Gimp 2.10/Win10

For g'mic, David used to include in the code a script-fu that is a shell to run several gmic commands in a sequence.

This an attempt to emulate Nidhoggs workflow. Never going to be as good creating something from scratch, leaves a halo for example, easily fixed but this is just for a bit of fun.

Put the attached scm in your scripts folder, the entry is down with the gmic entry. Very slow, have a cup of coffee or take the dog for a walk

@ Dionisio, sorry if it was old version. I can't seem to find anymore the topic where from it was downloaded. That was years ago.
Attached it for you.
Thanks Rich. I tried to compile Colorblur on Linux 64 but didn't succeed.
Nagged about gegl dependencies, installed them via synaptic but still couldn't fet it to compile.
The problem is that it's very hard to get exactly same result with other filters on 2.10
Managed to get close using G'mic blur [bloom] Saturation and then Gaussian Selective Blur with high values and LCh Color Blending Mode.
I'm using 2.10 only on Linux, Windows version throws Exception error after few launches, with portables too argh.

It is mostly compiler issues,lots of g_thread_create deprecated use g_thread_new but then that uses a different number of parameters. No way to win



Certainly is difficult and very much depends on the original image.

This in linux Gimp 2.10

Yeah the results vary lot depending on image, which is why I change some of the settings on the go.
Like this one. Skipped mighty details
After the two Gmic steps I created 2 duplicate layers.
Middle one for the colorblur, with different settings than originally.
On uppermost I used high pass script by RobA. Radius 2, Contrast 30, Greyscale. Changed Blend Mode to Grain Merge.
Did not remove background because wanted to see what will happen.
It was mostly okay but there were few blue and white flakes, that I smudged in the end.

Last one for now, because I managed to reach my goal on 2.10 with this project.
No need for that old Colorblur anymore, solution was to use gaussian selective blur and custom color curve.
I found the curves from an old topic, it's a big list of useful curves that can make a drastic change in the final outcome.
Sunrise Princess preset was used on Wonder Woman.
(The model can be found with google search, it should be in the first row of images)

This workflow is very nice.
I like the effect of Tone Mapping (fast); Had never used it before.
I did another try using Selective Color Blur, and then fooled around with Newsprint on the result.

original image: pngall

I don't seem to have an option for the selective colour blur so I am stuck. Any suggestions?

You may use saturation, with different strength for red (mid), green (low) and blue (high).

Played with this tutorial, as usual in a bit heretical way, to get an interesting draw/paint look.

original


outcome (image size scaled)

Really liked the old-school comic book look, just like on the original comics from the 60s - 70s. Hope to put this knowledge to good use!