I'm thinking of undressing in public.
Why do you want to be naked in public?
It will give me a sense of freedom
It is wrong to be naked in public and you should not be exposing your body to others. People, especially children, should not have to see you undressing while they go about their business.
I can remove my pants in the library. It's possible they will let you.
Since a library is a public space, I have to insist that you not take off your clothing in there, since the same laws about public nudity apply in there as they do anywhere else. You could be thrown out, or even arrested for acting this way, and that would certainly impede your sense of freedom.