Sorry for this nooby question but I'm searching for about an hour or so.

What I found is that the help at least tells me that it is possible,

You can use compositing networks to edit textures, post-process rendered frames, or perform any other image manipulation in Houdini and make the image data available to other nodes.

but it doesn't tell me how to do it.

How do get the image I edited in a compositing network to a color map or any kind of textureslot

/img/texturetest/blur1 doesn't work

Try oppathToCop/

Nailed it
But I don't understand why the color map slot has no “Choose Operator” dialog because this seems to be an obvious feature at this place, isn't it?

Korny Klown2
But I don't understand why the color map slot has no “Choose Operator” dialog because this seems to be an obvious feature at this place, isn't it?

That's a good point, as it would be handy.

The explanation is that it appears the parameters that are exposed to the user does not have this capability. You can see the available options by going inside the shader, finding the bit that exposes the parameter field on the UI. Play with the different options. It needs to be a string for the shader to work.

You'll see there is no Choose Operator option.