how to vectorize closed line

Hi there!! I am beginner and I wonder about vectorization.

I get contour line from topographic map. and now, I try to vectorize each contour line.

When I search about vectorize, I just find about low vector and column vector. I don't want that information.

How can I vectorize contour line? please refer my image

[KSSV]

What do you mean by vectorizing contour line?

[Stephen23]

What exactly do you expect if you "vectorize each contour line" ?

What would the output be ?

[Kwanghun Choi]

actually, I don't understand what vectorization mean. My final goal is input elevation as z value. but It is impossible to input elevation at each contour manually.

I refer some paper, and these say that vectorization is first step, and input elevation is next. that is why I am looking for vectorization.