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