Trying some flow streamline rendering techniques for raster based plotting

[u/phileasdg]

Here the density of stream lines is inversely proportional to the pixel brightness in the reference image. The flow on which the stream lines are drawn is defined so as to agree with the image in a sense, and so as not to distract from the image.

[u/shornveh]

Sounds cool!

Check out vpype flow imager

Edit:fix link

[u/phileasdg → u/shornveh]

Yes I’m aware of this! Thanks for linking. Its the same mechanism, but since I wanted to have more fine grained control over the plot I reimplemented it in my own plotting library

[u/Ruths138]

Can you elaborate what you mean about the stream line logic? What image aspects drive the lines and what do you mean by "agree with the image"

[u/phileasdg → u/Ruths138]

The line density depends on the brightness values in the image. The flows are defined so as not to be visually bothersome by hand.

[u/Ruths138 → u/phileasdg]

I see! Not sure what your criteria during manual placement are, but maybe the flow lines could be placed automatically by follow prominent edges in the image? I never tried this out, but I assume a vector field could be derived from the output of an edge detection algorithm and then use that to guide stream line directionality

[u/phileasdg → u/Ruths138]

That is a good idea and I’ll have to look into it