WHITE PLAINS, N.Y. — It might be drab and drizzly in this community about a half-hour drive from Manhattan. But on three floors inside a nondescript office building, it's Blue Sky all the time.

That's the name of the 'toon factory where the "Ice Age" creatures evolved and "Robots" got into gear. And it's where today's "Horton Hears a Who!" began its journey from written page to the big screen.

Who would guess this small downtown thousands of miles away from Hollywood is home to an Oscar-winning computer-animation studio that ranks alongside Pixar/Disney and DreamWorks?

"Horton," the tale of a pachyderm who protects the speck-sized world of Who-ville from jungle skeptics, is the first full-length animated feature based on the works of the late Dr. Seuss (aka Theodor Geisel).

Winning approval from the Seuss estate and lining up such voice talent as Jim Carrey (Horton), Steve Carell (the Mayor of Who-ville) and Carol Burnett (the meddlesome Kangaroo) was one thing. Translating the book's distinctive drawings filled with floppy foliage, tilted towers and insectlike Whos into computer animation was something else.

"When we started, we were all intimidated by Seuss," says Chris Wedge, Blue Sky co-founder, "Ice Age" director and an executive producer on "Horton."

He and the rest of the crew were well aware that the animated gold standard of such adaptations is Chuck Jones' 1966 TV version of "How the Grinch Stole Christmas."

That was 30 minutes, padded with commercials. Blue Sky had to produce 88 minutes, daring to expand a beloved 72-page storybook by elaborating on the back story of the Whos and their lifestyle to do so. (Who knew the Mayor had 96 daughters or that little twerp Jo-Jo was his son? Or, as Horton says, "Oh-ho-ho, busy guy.")

"Frankly, I was terrified," Wedge says, "but everyone attacked it, and we are all very proud of it."

The decision to pair co-directors Jimmy Hayward, 36, a single rockabilly hipster with a turbo-charged personality, and Steve Martino, 46, a pullover-wearing family man with the calm demeanor of Perry Como, proved fortuitous when it came to inspiring the troops.

Both felt strongly that the Seuss universe, previously done in live action by 2000's "How the Grinch Stole Christmas" with Carrey as the larcenous Grinch and 2003's "The Cat in the Hat" with Mike Myers as the felonious feline, is better served by animation.

In their make-believe Who-ville, those twisty sky-high roadways are never at risk of tumbling.

Then there's the way that the animators decided to flesh out the look of the insectlike Whos. They took their cues from tufts of fluff that adorned their bodies in the illustrations and cut their fur to resemble clothing.

No one griped (too much) when the directing team told the crew what was required to portray the massive field of clover where Horton has to hunt down the single blossom that holds his speck.

"We wanted to have that feeling of when you turn the page and see what Horton has to face," Martino says. "It needed to have an epic quality." That meant a half-billion purple clovers with 800,000 hairs on each had to be created, "so it looked like a Kansas wheat field."

"Horton" already has earned the most valuable stamp of approval. The author/illustrator's widow, Audrey Geisel, was the one who handpicked Blue Sky out of the crowd of potential suitors to bring a high-tech "Horton" to the big screen.

"I'm not one to go commercial very easily," says the 86-year-old mistress of all things Seuss. While Geisel enjoyed Carrey's green meanie in "The Grinch Stole Christmas," she felt burned by 2003's "The Cat in the Hat" after Myers called the shots and injected blue humor into the material. "I like my little creatures kept in their little circle. I don't put them out very easily."

But a visit from Chris Meledandri, then-head of Fox animation who thought "Horton" with its three-act structure would be the perfect Seuss book to animate, persuaded Geisel to rely on the Blue Sky crew to be true to her husband's 1954 elephant adventure. "We bonded immediately," she says. "I thought, 'This is the man who will play the game fairly. He says what he means and he means what he says.' "

Her reaction to the final product? "I found it delightful," she says. "Nothing was lost in stretching it. There is tremendous interest in that megalopolis down there in the clover. Now that they have personalities, you feel a great deal more that they've got to be saved."