Joey McFarland issued a mea culpa Sunday -- this after there was some apparent outrage over the fact he brought a wallet-size picture to the L.A. premiere of 'Emancipation' Wednesday ... which he flashed to a reporter on the red carpet while discussing it.

McFarland was asked how he came to own the OG photo of "Whipped Peter" from 1863 ... and then he actually brought out and showed it off. His answer boiled down to seeing the importance of history and wanting to curate valuable artifacts like this one so that they can live and be preserved -- and so we can all learn a valuable lesson from the past.

On its face, there doesn't seem to be anything wrong with JMF's statement. But, of course, some took issue with his phrasing -- like saying he wanted a "piece of Peter" to be there that night -- and the optics of a white man owning and parading this pic around like a prop.

That's how a handful of folks interpreted his interview here anyway ... and it seems McFarland caught wind of that noise and felt compelled to explain himself.

He writes, "I wholeheartedly apologize to everyone I have offended by bringing a photograph of Peter to the Emancipation premiere. My intent was to honor this remarkable man and to remind the general public that his image is not only brought about change in 1863 but still resonates and promotes change today."

McFarland adds, "After uncovering Peter’s origin story with help from diligent historians, I spent the last few years working with the Emancipation creative time in order to bring his story to life so worldwide audiences would have an opportunity to appreciate his heroism. I hope my actions don’t distract from the film’s message." He says he simply wants to honor the legacy of Peter and others like him, and meant no harm in showing off the photo.