Coloured X-ray of a barn owl. A physicist has used X-ray to create an extraordinary collection of artwork. Arie van't Riets pictures reveal birds, fish, monkeys and flowers in an incredible new light. The 66-year-old, from Bathmen in the Netherlands, began X-raying flowers as a means to teach radiographers and physicians how the machine worked. But after adding a bit of colour to the pictures, the retired medical physicist realised the potential for an exciting new collection of art. (Photo by Arie van't Riet/Barcroft Media)

Transgender model and musician Jessica Cortez reacts as she is prepared before walking in the CHULO underwear show during New York Fashion Week, which raised money for transgender and cisgender young women victims of violence, in New York, U.S., February 7, 2019. (Photo by Andrew Kelly/Reuters)

A protester is taken away by police during an electoral campaign closing rally of Spain's far-right party VOX in Madrid, Spain on April 26, 2019. (Photo by Juan Medina/Reuters)

Boys contort their faces as they participate in a game where they need to slide a coin from their forehead to their mouth to win, during the annual Feast Day of St. Rita of Cascia in Manila, Philippines on May 19, 2019. (Photo by Noel Celis/AFP Photo)

Charli XCX performs on day three of the Pitchfork Music Festival at Union Park on July 21, 2019 in Chicago, Illinois. (Photo by Michael Hickey/Getty Images)

This family of warthogs regularly visited our campsite in the Ethiopian highlands so I set up a remote camera with a wide-angle lens to photograph them as they rummaged around for food. They just had a mud bath. (Photo by Will Burrard-Lucas/Caters News Agency)

A model presents a creation by British designer Vivienne Westwood as part of her Spring/Summer 2018 women's ready-to-wear collection show during Fashion Week in Paris, France September 30, 2017. (Photo by Charles Platiau/Reuters)

A participant in costume uses a mobile phone at a Halloween event in Kawasaki, south of Tokyo, Japan October 29, 2017. (Photo by Kim Kyung-Hoon/Reuters)