Actress Jessica Alba (C) arrives at the Excelsior Palace in Venice August 31, 2010.[Photo/Agencies]

Related Photos:Jessica Alba at a photocall for movie 'Machete'

Jessica Alba arrives at 'Machete' red carpet at 67th Venice Film Festival

The Venice film festival opens on Wednesday with "Black Swan," starring Natalie Portman as a ballet dancer in New York whose position is threatened when a beautiful newcomer arrives.

The thriller, directed by Darren Aronofsky, officially kicks off the annual celebration of cinema on the Lido waterfront where stars, fans and reporters rub shoulders for 11 days.

Festival director Marco Mueller has opted for youth in his choice of directors of the 23 competition films, and he will also hope that the presence of Hollywood mavericks can make up for the expected shortage of A-list celebrities this year.

Jury president Quentin Tarantino, who must ultimately decide who walks away with the coveted Golden Lion award at the closing ceremony on September 11, said his time on the picturesque island would be more work than play.

"There's a lot of really exciting movies, exciting directors. It's a fantastic line-up," he told Reuters on arrival. "I'm keen with anticipation.

"I've been on a few juries and I love it. It's a joy to me. But it's work. We're not here for vacation."

Venice, the world's oldest film festival and one of its most prestigious, has long been looking over its shoulder at Canadian rival Toronto, with which it overlaps and which is seen as cheaper and more business-focused than the Italian event.

The competition has intensified, as many movies with world premieres in Venice hit Toronto just days later and others go straight to the Canadian festival.

Mueller said he believed the two events could continue to exist side-by-side.

"I'm quite convinced that Venice is still strong," he told Reuters, adding that "the visibility, the impact of a film is created here and the market potential of the film is then completely assessed only in Toronto."

DISRUPTIONS

Venice faces the additional challenges this year of a major expansion project disrupting the festival and the closure of the Des Bains hotel, one of only a handful of top residences on the Lido immortalized in the 1971 film "Death in Venice."

The average age of filmmakers in the main competition this year is an unusually low 47, and includes 41-year-old Aronofsky, winner of the Golden Lion in 2008 with "The Wrestler," and Oscar winner Sofia Coppola, 39, with comic drama "Somewhere."

At the other end of the age range are 78-year-old Monte Hellman, competing with low-budget crime drama "Road to Nowhere," and Polish filmmaker Jerzy Skolimowski, 72, on the Lido with the thriller "Essential Killing."

In Essential Killing, actor and painter Vincent Gallo stars as an Afghan Taliban fighter who is captured but escapes on his way to a secret detention center in Europe.

The subject matter, and Gallo's reputation as an uncompromising, eccentric artist, make it one of the more eagerly anticipated movies in competition.

Actor and director Casey Affleck presents documentary "I'm Still Here," about his brother-in-law actor Joaquin Phoenix's decision to retire in 2008 and reinvent himself as a hip-hop musician.

A TV chat show appearance last year as a mumbling, shaggy-haired guest had industry watchers wondering if Phoenix's new act was a hoax, and already critics are debating whether I'm Still Here is more "mockumentary" than documentary.

And Julian Schnabel directs "Slumdog Millionaire" star Freida Pinto in "Miral," about an orphaned Palestinian girl growing up in the wake of the first Arab-Israeli war, who finds herself drawn into the conflict.