Nudity "decriminalized" meaning?
In most cases it means that the offense has is no longer classified as a misdemeanor or felony crime but rather a violation like littering or a speeding ticket. If convicted the penalty would not involve any jail time, usually just a fine. Most states have laws that limit the maximum fine for violations to some reasonable amount like three to five hundred dollars, but there are some fines for violations that can go as high as a thousand dollars. It is rare for someone to receive a fine that high for a violation but you would have to look at the city, county or state law to know what the maximum penalties are.
There is case law in Florida that simple nudity is not the crime of Indecent Exposure. There must be some overt act of a sexual nature to make it criminal behavior. That might be why some local jurisdictions are coming up with the non-criminal violation offense for public nudity.