migrating 2.8 bash scripts to gimp 3

[vince]

Sorry for the previous message, I got lost. Here is a working solution (that from MrsP-from-C):

Code:

gimp -i --quit --batch-interpreter=plug-in-script-fu-eval -b \
"(\
    let*(\
        (image (car (file-png-load 1 \"input.png\")))\
        (my-drawable (vector-ref (car (gimp-image-get-selected-drawables image)) 0))\
    )\
    (gimp-drawable-desaturate my-drawable 0 )\
    (file-png-export 1 image \"output.png\")\
)"

Now, I notice the good old plug-in-colortoalpha is absent from the procedure browser.