Yann Martel, however, says he thinks director Ang Lee did a pretty good job of pulling it off.
"It's very faithful to the book, it's visually absolutely stunning and it's a whole trip," the Canadian author said in an interview as people lined up to see the film version of his novel at Montreal's Festival du nouveau cinema over the weekend. The movie will open across Canada next month.
"Life of Pi," which has sold millions of copies worldwide since it was published in 2001, counts U.S. President Barack Obama among its fans. In a letter to Martel two years ago, Obama described the 2002 winner of the prestigious Man Booker Prize as "a lovely book — an elegant proof of God, and the power of storytelling."
But most filmmakers shrank from adapting it for the big screen after it was published. Even Martel acknowledges the dense plot has enough material for multiple movies.
Then came Lee, who was undaunted. Taking it on four years ago, he tackled the compelling adventure story of an Indian boy named Pi who is shipwrecked with a ferocious Bengal tiger, and combined the tale with cutting edge 3D technology.
The technology works with the film's stunning locales and exotic creatures to amazing effect and solves the problem of pairing actor Suraj Sharma, who plays Pi, with a carnivore.
The computer-generated tiger is indistinguishable from the real thing. It even had members of the Montreal audience jumping in their seats when the hulking beast snarled and lunged.
"You can't use live animals in this type of thing so it needed technology, it needed an incredibly determined director to do it and Ang Lee was that director," Martel said.
Martel wrote "Life of Pi" while living in Montreal and has since moved to Saskatoon.
He loved Lee's previous movies, which include "The Ice Storm," "Brokeback Mountain," and "Crouching Tiger, Hidden Dragon," and was thrilled when the director took on "Life of Pi."
"He's a remarkably versatile director — think of "Hulk" and "Crouching Tiger, Hidden Dragon," which has special effects and think of "Brokeback Mountain," which is a very simple, emotional movie. A huge array of things required and he had all those talents to pull it off."
As close as Lee came to the original novel, Martel was prepared for the book's meaty plot to be trimmed.
"A novel like "Life of Pi" could potentially make for five movies," he said. "This is a selection from "Life of Pi" which is why I always emphasize this is Ang Lee's movie. If you love it, the praise goes to him. If for some reason you don't like it, that goes to him too.
"It's not good to compare the two," Martel added, saying the film and the novel should be judged on their own merits as separate products.
Martel did read early versions of the screenplay and gave some feedback on small points such as turns of phrase. But he also emphasized that he stayed out of Lee's way.
"He's going to make the movie he wants to make," he said. "I'm going to let him do it."
"Life of Pi," which premiered at the New York Film Festival in September, goes into wide release on Nov. 21.
One person Martel doubts will be lining up for it, however, is Prime Minister Stephen Harper.
Martel started a campaign in 2007 to get Harper to read more and every two weeks sent him a new book. He eventually passed on more than 100 books to the prime minister, although "Life of Pi" wasn't on the list of the ones sent.
Martel shrugged when asked if the film version might be more appealing for Harper.
"I would bet he's more inclined to watching movies than he is to reading books," Martel said. "I doubt he'll see it though because if he goes, for sure people are going to take pictures of that and bring it up.
"At most, he might watch the DVD in a year's time."