After pseudo TSP or I must say Hamiltonian Cycle from a brightness of a mesh or a topology. Here is an example of the possibility to convert an image to CMYK (Cyan Magenta Yellow Key) paths.
Everything begin with an image, cartoon image seems good
Superman from © John Byrne / DC Comics / Urban Comics
Image is transformed to a mesh then RGB colors are transformed to inverted powered CMYK values.
it means CMYK value = 1 - RgbToCmyk(rgb)^power. Here Power is 0.5 as it seems to work well.
Circle Packing tool from Nautilus plugin are then used in order to be then able to have a mesh depending on the brightness. Indeed 4 meshes. I use a unitless coefficient for the black radius 0.001 or 0.0005 are good, the little the more slower. White radius is here taken 10 time bigger than the black radius.
I found that faster than Remesh by Color
Then some pseudo TSP are made, here using the dual mesh.
Paths are smoothed then plugged into Graphic+ and Bitmap+ from David Mans in order to have some rendering of the CMYK drawing using a plotter.
You can choose to scale the output image.
This tool was done to answer this question
Plugins
Work with Nautilus 0.9.9
Image to CMYK Hamiltonian Cycle Laurent Delrieu.gh (1.3 MB)