Hi,
i’ve implemented an algorithm to extract the most important colours of an image. Here is an example of what it does:

Here are more examples

The algorithm is a slightly modified version of median cut and it is quite the same as the one used in JFIF jpeg library for reducing colours and indexing images. There is a quite good and easy to understand paper from leptonica on this topic. Thanks to pippin for guiding me to median cut ;) .

I also ported the shade selector algorithm from MyPaint to Krita. This is already a docker in Krita, but it isn’t connected yet:
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Also, Pigment is not yet used, which is important to support colour spaces properly. Anyway, the next step will be to implement all widgets with dummy graphics, so Pigment and connection must wait.