inpaint using other image as example

[Hugo-Trentesaux]

My goal is to paint inside an image using an other image as example.

For example I would like to paint in the first image where the 'A' is transparent (here rendered with checkered pattern) using the second image as example. The result would be something like the third image but with pixels generated so the border matches.

I tried with commands like

texture-synthesis --inpaint-channel a --sample-masks IGNORE ALL \
-o output.png generate A-alpha.png dark-smoke.png
# expecting it to paint inside A-alpha using examples from dark-smoke

but it does not work and gives me

as if it did use the alpha channel of A-alpha but choose to paint inside dark-smoke instead of painting inside A-alpha.