How to make a vector stroke in illustrator?

Question

Vector graphics

The task is as follows:
there is a psd file in it there are a lot of small raster images scattered over layers, the task is to open the file in a chandelier and make a vector stroke for each picture, and save it all as a pdf
layer with pictures
a layer with a stroke
I am almost 100% sure of the fact that there is a way to do this, except for sitting and tracing each picture with pens,
making a stroke in fsh and then converting it to a vector does not help, because in the vector you get two lines and you need one
how to do it all in fsh I can imagine but how to do it in illustrator?
my experience with illustrator does not allow me to do this even with the help of google
all this is needed for a cutting plotter that refuses to be friends with contours