Ategwa says his vivid paintings of life in Cameroon's biggest city, Douala, sell for up to £20,000 ($26,000).

He jokes that family members educated to a higher level than him "now respect me a lot... because I am the most successful".

"It's the only thing I know how to do. So painting is my life," Ategwa told the BBC. "At times when I'm angry, painting calms me down."

He never formally trained as an artist, and says he has used the same bold approach to colour since the age of seven.

Although his works feel like immediate portraits of bustling city life, Ategwa told BBC Focus on Africa that they're filtered to an extent by memory and imagination.

"All of them are inside my head, because they're things that I see every day going to my workshop."

"I do a sketch first before I start painting," Ategwa says of his technique. Many are imposing in size - one of his recent works is more than 2 metres tall and 4 metres wide.

Walking around Douala, "you see many things like markets, shops, hairdressing salons," Ategwa says.

There are lots of sounds too, including "influences from Congolese music and Ivory Coast. You hear that everywhere."

An exhibition of Ajarb Bernard Ategwa's work at London's Jack Bell Gallery has just ended, while new works will be presented at New York's Armory Show in March.

"I've not been to school, but I am a successful man today. My paintings are shown all over the world," Ategwa says.

"Not everything is just about education, education, education. If you have a child and they love drawing, please allow them to do their drawing.

"Allow [young people] to follow their passion."