With analysts saying 2010 had the lowest movie attendance in five years, how can IMAX claim to have doubled its gross to $546 million over the previous year?

The large-format screen company owes its success to a one-two-three combination of increasing its number of theaters by about 100 (climbing to 517 total screens), charging more than the average ticket price (an added premium of about $5, or $6 if the movie’s also in 3-D) and choosing only a handful of Hollywood films to release in its biggie-sized format.

IMAX also benefited from the spectacular worldwide showings of three particular films: Avatar, which was released in late 2009, earned most of its $2.7 billion take in 2010; Alice in Wonderland, which collected about $1 billion; and Harry Potter and the Deathly Hallows — Part 1, which currently stands at $900 million.

James Hyder, who covers the large-format industry as editor and publisher of the trade journal, says IMAX can separate itself from the fortunes (or lack thereof) of the overall box office by selecting only a limited number of titles to release on its bigger screens. In 2010, the company release 16 titles, up from 13 in 2009. “Naturally, they choose what they think will be the most popular and successful films,” Hyder says. “They pick the Harry Potters and top franchise films, so it’s not surprising they do so well considering all the factors combined.”

An IMAX rep says the company intends to continue adding theaters in 2011, and already has 13 movies on its slate for this year, among them Pirates of the Caribbean: On Stranger Tides, the robo-boxing tale Real Steel, and Cars 2.

The massive earnings are also, weirdly, a slap in the face to comedian Aziz Ansari.

The Parks and Recreation actor took to Twitter and his blog, lambasting IMAX in spring 2009 after seeing a movie in its “IMAX Experience” format — which is bigger than average multiplex screens, but only one-third the size of the well-known, gigantic IMAX setups that made the company famous. “Basically IMAX is whoring out their brand name and trying to trick people,” Ansari wrote.

Hyder agrees that IMAX is offering two different products it doesn’t differentiate, and it can lead to confusion. “It’s bigger, sharper and has more contrast than an average conventional theater, but only when compared to the classic giant-screen film system does it become clear it’s a different experience,” he says.

Many of the company’s new theaters in 2010 were in this format, Hyder adds, but the spectacular earnings show that “by and large, that hasn’t stopped the public from coming.”