Oprah Winfrey arrives at the "Precious" film screening during the 34th Toronto International Film Festival, September 13, 2009. [Agencies]

TORONTO- When it comes to generating Oscar buzz, a film like "Precious" could do far worse than having Oprah Winfrey's backing.

America's most influential tastemaker said she came to the project late, signing on as executive producer only after the Lee Daniels-directed tale of the abuse and redemption of a big city teenage girl was mostly ready for the big screen.

Judging from the reaction to its weekend screening at the Toronto International Film Festival, long considered a launch pad for Academy Award campaigns, "Precious" is likely to have a powerful impression on film audiences and Oscar voters.

"It is so raw that it sucks the air out of the room by the end of the film," Oprah told reporters before the movie's gala presentation in Toronto.

"I think it is a good thing that you are taken to that level of engagement with this film," Oprah said, seated alongside newcomer Gabourey Sidibe who plays the title role. "A film like this comes along once in a time."

Set in Harlem in 1987, "Precious: Based on the Novel 'Push' by Sapphire," tells the harrowing story of an obese, illiterate teenager named Claireece "Precious" Jones, who was impregnated by her own father for a second time.

Walking through life in sullen silence, Precious endures brutal physical and emotional abuse from her mother (Mo'Nique), a welfare cheat who spends her waking hours in front of a grainy TV set in their darkened tenement.

DIAMOND IN THE ROUGH

"Precious" is a gritty drama, just the kind of movie that Oscar voters like. Yet, in this recession when audiences have favored uplifting tales, "Precious" also gives filmgoers a story of survival and redemption.

John Anderson, critic for showbusiness newspaper Variety, called it "like a diamond -- clear, bright, but oh so hard."

Precious eventually finds her way to a school where a caring teacher nurtures the inner self-worth that glows inside her. Exactly how she overcomes the demons that seem to stalk her every step gives the story its power.

"For people who have endured that kind of situation -- me being one those people, its message is hope," said Tyler Perry, perhaps best-known for Madea, his African-American matriarch character. Perry, who has said he grew up with an abusive father, serves an executive producer on "Precious."

"(Precious) walks away with her life, she walks away with her faith, her life, and love for the first time ... That's what I'm hoping people walk away with," said Perry, who as a director scored his second No. 1 movie of the year this weekend with "I Can Do Bad All By Myself."

Many of the people involved with "Precious" said making the film had a powerful emotional impact on them.

Mary J. Blige, whose song "I See in Color" resonates during a key scene in the movie, was particularly moving when asked about the emotions she wanted to tap when writing the lyrics.