Comic-Con is expected to raise $140 million for the local economy this year

Several actors and actresses were seen wearing an 'A' pin in memory of the late actor Anton Yelchin at the premiere

On Wednesday night, Paramount was staging a glitzy open-air US premiere of Star Trek Beyond

The convention is expected to welcome 130,000 cosplayers, movie executives, sci-fi fans and bloggers

The event, which has become an increasingly important tool for Hollywood to generate interest in upcoming movies, is due to kick off on Thursday

Comic and film fans from across the world will down costumes this week and descend on California to spend four days geeking out


From Pokemon onesies to Disney frocks, comic and film fans from across the world will don costumes this week and descend on California to spend four days geeking out.

Every July, San Diego transforms into Nerd Town USA, as tens of thousands of monsters, aliens, manga characters and caped crusaders throng the streets for Comic-Con International.

Since its humble beginnings in 1970 as a convention of a few dozen geeks who swapped superhero magazines, it has exploded into America's largest and most spectacular pop culture event.

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From Pokemon onesies to Disney frocks, comic and film fans from across the world will don costumes this week and descend on California to spend four days geeking out. A woman dressed as Batgirl pictured above

A woman screams as she tries to pose for a photo with zombies at 'The Walking Dead' booth during Preview Night at Comic-Con International held at the San Diego Convention Center on Wednesday in San Diego

On Wednesday night, Paramount was staging a glitzy open-air US premiere of Star Trek Beyond, attended by the cast and crew and complete with a live performance of Michael Giacchino's score by the San Diego Symphony. Actress Zoe Saldana pictured left and Zachary Quinto, right

The convention is expected to welcome 130,000 cosplayers, movie executives, sci-fi fans and bloggers from Thursday to feast on all manner of panels, screenings and other fan events and attractions.

The center of the Comic-Con galaxy is the 6,500-seat Hall H, where big name stars drop by to promote their films and TV shows, and fans have been known to wait in line for more than 10 hours to get in.

For Americans, the price of attending Comic-Con is estimated at around $1,850, including entry badges, air fare to San Diego, hotels, costumes and food - and costs rise significantly for those flying in from abroad.

The evolution of smart phone technology and the emergence of social media has raised the specter of piracy this year, with one big studio reportedly having pulled out over leaks of footage onto the internet.

Last year, a Warner Brothers reel for Suicide Squad intended only for the convention attendees was quickly bootlegged and put online, forcing the studio to hastily release a brushed-up version.

Actress Katee Sackhoff and actor Karl Urban are pictured as they arrive for the premiere of Star Trek Beyond at Comic Con

Simon Pegg and Sofia Boutella were seen among several other stars wearing an 'A' pin in in memory of the late actor Anton Yelchin

Actors Chris Pine (left), John Cho (center) and Karl Urban arrive for the premiere

Producer J.J. Abrams arrives waves as he at the world premiere of 'Star Trek Beyond' in San Diego on Wednesday

Justin Lin, Chris Pine, Karl Urban, John Cho, Zachary Quinto, Zoe Saldana, J.J. Abrams and Sofia Boutella pose together ahead of the film premiere on Wednesday night

Trailers for Deadpool and X-men: Apocalypse also leaked onto the internet during last year's convention.

The Los Angeles Times and entertainment website The Wrap reported that Deadpool distributor 20th Century Fox decided to sit out Comic-Con this year over piracy concerns, although the studio has declined to confirm this was the reason.

Shawn Robbins, a senior analyst at movie data website Boxoffice.com, raised the possibility that other studios might start pulling back from making exclusive material available at fan conventions.

'The exclusivity of it has already disappeared in recent years, not just due to pirated leaks but even because of official trailer releases that have been timed during or close to various conventions like Comic-Con and CinemaCon,' he told AFP.

'While these gatherings are about much more than just a few minutes of footage from movies, that has nonetheless become a big selling point.'

Cosplayers are pictured above as they attend preview night on Wednesday night

A general view inside the San Diego Convention Center at Comic-Con International 2016 preview night

Wonder Woman costume is displayed at Comic-Con International 2016 preview night

Described by Rolling Stone magazine as the 'Super Bowl of people who don't like watching the Super Bowl,' Comic-Con boasts a cornucopia of stars hawking their latest movies and TV shows.

On Wednesday night, Paramount was staging a glitzy open-air US premiere of Star Trek Beyond, attended by the cast and crew and complete with a live performance of Michael Giacchino's score by the San Diego Symphony.

Several actors and actresses including Zoe Saldana, Sofia Boutella and Zachary Quinto, as well as producer J.J. Abrams were seen wearing an 'A' pin in memory of the late actor Anton Yelchin at the premiere.

The sci-fi sequel's U.S. debut will mark the first-ever outdoor Imax screening.

Attendees gather for the start of Comic-Con International in San Diego on Wednesday

Bunny Knowble, dressed Galactus Eater of Worlds, crosses the street with a crowd on the way to Preview Night at Comic-Con International held at the San Diego Convention Center

Bersain Gutierrez, dressed as Superman, poses in front of the convention center before Preview Night

Beth Namishia, left, Megan Madura, center, and Jodie King, dressed as Ghostbusters, pose in front of the convention center

Warner Bros takes over Hall H for two hours on Saturday, with Conan O'Brien as host, to pull back the curtain on its highly anticipated slate of both DC Comics movies and non-superhero offerings.

Stars expected to attend include Wonder Woman leads Gal Gadot and Chris Pine, while Will Smith, Jared Leto, Margot Robbie, Cara Delevingne and director David Ayer are due to show up for Suicide Squad.

Next spring's Kong: Skull Island will be presented by Tom Hiddleston, Brie Larson and John Goodman and there will be a first look at Harry Potter spin-off Fantastic Beasts and Where to Find Them with Eddie Redmayne and Colin Farrell.

Another of the most talked-about offerings of the convention will be Marvel's Hall H presentation later on the same day, which should include an appearance by Chris Pratt for Guardians of the Galaxy 2.

Ringmaster Kevin Feige may also treat audiences to a peek at Dr Strange, Spider-Man: Homecoming and Thor: Ragnarok.

The convention is expected to welcome 130,000 cosplayers, movie executives, sci-fi fans and bloggers from Thursday to feast on all manner of panels, screenings and other fan events and attractions

Denise Zesati, dressed as Pokemon Pikachu, stands in line to buy collectables during Preview Night

Hordes of zombies, legions of Stormtroopers, leagues of superheroes and crews of Starfleet officers have already begun crawling, marching, flying and beaming into San Diego for Comic Con

Attendees gather for the start of Comic-Con International in San Diego on Wednesday

During the festival's preview night, con-goers with four-day passes have first crack at the collectibles, free swag and photo opportunities on the San Diego Convention Center floor

On the television front, AMC has perhaps the pick of the convention with panels devoted to The Walking Dead, the most successful show in cable television history, and its spin-off, Fear the Walking Dead.

Sue Kroll, Warner's president of worldwide marketing and distribution, sees Comic-Con, which is expected to raise $140million for the local economy this year, as one of the company's favorite events.