Wu Hongli and his book Cats in Beijing. [Photo by Wu Hongli/provided to China Daily]

One of Wu's favorite cat photographers is the American Walter Chandoha, who died on Jan 11 last year aged 98. From his childhood Chandoha took photos and had eventually taken more than 225,000 of them, about 90,000 being of cats.

He was once quoted as saying: "Cats are my favorite animal subject because of their unlimited range of attitude, posture, expression, and coloration."

Before Chandoha died he was able to work on one final book, Cats. Photographs 1942-2018, a career retrospective featuring about 300 of his greatest cat photos.

In the book, he wrote: "I relished the challenge of making photographs of cats and quickly saw the potential of attempting to capture their naturally expressive personalities. The photographic possibilities and challenges seemed endless."

He once saw a photo in which a cat was yawning and stretching on a balcony. Behind the cat was a rainbow, making it look like the cat, in a very artistic way, was passing wind. "Cats cannot and will not be rushed." Wu says. "They have their own schedules. When the moment comes you find the right angle and press the shutter."