The Mother's Day photo released on Sunday by the Princess of Wales had been edited, Kate Middleton said on Monday, apologizing for any "confusion" those alterations caused.
"Like many amateur photographers, I do occasionally experiment with editing," she said in a statement.
She added, "I wanted to express my apologies for any confusion the family photograph we shared yesterday caused. I hope everyone celebrating had a very happy Mother's Day."
The princess had on Sunday posted a greeting on an official social media account.
The post included a photo of Kate with her three children, Princes George and Louis and Princess Charlotte.
Kensington Palace also distributed the image.
MORE: Post-surgery Princess Kate photo retracted after concerns it was 'manipulated'Kate credited her husband William, the Prince of Wales, as the photographer.
The photo was picked up by several international news agencies, including The Associated Press, Reuters, Getty Images and Agence France-Presse.
Those agencies later retracted the image, saying it may have been edited prior to its release by the royals.
The Associated Press said Sunday it appeared "the source had manipulated the image in a way that did not meet AP's photo standards."
PA Media Group, a news agency in the United Kingdom, also retracted the image.
MORE: Prince William and Kate's 3 kids: What to know about George, Charlotte and LouisKensington Palace said Monday it would not be reissuing the original unedited photograph of Kate and her children.
Hany Farid, a computer science professor at the University of California, Berkeley, told ABC News his analysis of the photo shows only "relatively minor photo manipulation."
"If you look at the sleeve of the girl on the right, you see what looks like traces of manipulation," Farid said, referring to the sleeve of Charlotte's sweater. "I think most likely it is either some bad photoshop to, for example, remove a stain on the sweater, or is the result of on-camera photo compositing that combines multiple photos together to get a photo where everyone is smiling. For the latter, if the subjects move between successive images, it can cause this type of ghosting."
Farid continued, "Either way, I think it is unlikely that this is anything more than a relatively minor photo manipulation. In addition, there is no evidence that this image is entirely AI-generated."
