There is no such thing as perfect pitch. A perfectly tuned piano is flat on the low end and sharp on the high end and every interval is out of pitch just slightly so that it balances out. Thirds are tuned sharp and they get sharper and sharper as you go up the scale. Fifths are tuned flat. Pianos are tempered so that you can play in every key.
Violins and trombones are capable of playing in perfect pitch but then if any vibrato is applied, (and it always is) then the player is constantly pulling the pitch up and down.
Perfect pitch is the ability to identify a note that is heard. My mother’s piano teacher was fascinated by mother’s ability. The teacher would send my mother into another room and ask her to name a note. My mother got it right every time. Her real name is agent was her voice, though. It ran in the family, her cousin sang with the Metropolitan opera. He was a baritone.