At a preview screening of “The Diving Bell and the Butterfly” last week, Julian Schnabel was loving life. The director’s extraordinary new movie, a shattering but unsentimental tale of a high-flying magazine editor laid waste by a stroke, had cast a spell on the audience that he was in no hurry to break. By way of greeting, he said, “Every day above ground is good.”

Based on a memoir by the magazine editor Jean-Dominique Bauby, Mr. Schnabel’s rich and imaginative film tackles a subject he said has always troubled him: death. The director’s paintings made him an art-world star in the 1980s, but now Mr. Schnabel spends much of his considerable energy making movies, and he discussed his third film — which earned him Best Director honors at Cannes and will make its American premiere this weekend at the New York Film Festival — with the ease of someone who was pretty sure he’d gotten it right. His comments often caromed around any discernable point; several times he concluded anecdotes with a satisfied air, only to realize he’d forgotten the question. But one salient point did emerge: “The Diving Bell and the Butterfly” is Mr. Schnabel’s most personal film to date.

Mr. Schnabel usually sticks to what he knows. In his 11-year career, he has made only three feature films, each about an artist: “Basquiat” (1996) was about the street-art enfant terrible who romanced the New York art scene in the early 1980s; “Before Night Falls” (2000) was a biopic of the Cuban poet Reinaldo Arenas. Now he offers his portrait of Bauby, the French Elle editor who wrote a best-selling account of his life despite losing his speech and virtually all muscle movement. Suddenly reduced, at age 43, to an agonizing, womb-like state known as “locked-in syndrome,” the former man-about-town turns his despair into art, a metamorphosis Mr. Schnabel’s adaptation renders with deeply moving sincerity.

Evident in the film is the deep connection Mr. Schnabel felt to Bauby’s memoir, which arrived in 1997 just days before Bauby’s death at 44. The director first read it in 2001, when it was given to him by the nurse of a friend suffering from multiple sclerosis. When the British screenwriter Ronald Harwood’s script came his way two years later, Mr. Schnabel’s 92-year-old father was battling prostate cancer. “Having never been sick, he was unprepared and terrified of death,” Mr. Schnabel has written. “I felt like I failed him because I couldn’t help him through that.” Making the film, he said, was his attempt to atone for that failure.

“The Diving Bell and the Butterfly” is not as depressing as it sounds, but it does engage tragedy with a striking directness. Filmed entirely from the point-of-view of Bauby (Mathieu Amalric), the first 20 minutes are straight out of a nightmare. He emerges from a coma, facing a phalanx of nurses and doctors; he speaks, or thinks he does, only to realize no one can hear him; and he can’t move a muscle. In one horrifying scene, he watches as his damaged but still-functioning right eye is sewn shut.

To make the camera a more convincing stand-in for Bauby’s eye, Mr. Schnabel and his cinematographer, Janusz Kaminski, put images in partial focus using a swing-and-tilt lens. (At one point, Mr. Schnabel even screwed his own glasses onto it.) With the camera replicating his wandering gaze and Mr. Amalric narrating his interior monologue, Bauby’s pain and bewilderment are transferred onto the audience so completely that it’s almost unnerving.

It’s a risky, but ultimately successful, stylistic choice that testifies to Mr. Schnabel’s commitment to Bauby’s story. “I thought it was extremely important to get it right,” he said, noting that the memoir remains hugely popular in France. Mr. Schnabel shot much of “Diving Bell” at the seaside hospital where Bauby was a patient and spoke with people who knew him. Bauby’s nurse and physiotherapist even play themselves in the film.

There was also the question of language. The film’s production company, Pathé, wanted Mr. Schnabel to make the film in English, but Mr. Schnabel resisted. “The book was written in French, by a Frenchman, in a French hospital,” he recently explained to the Hollywood Reporter. “And I’d be damned if English and American people were going to make believe they are French.” He ended up convincing the film’s financiers, then resolved to learn French on the set.

A French cast that includes Emmanuelle Seigner, Niels Arestrup, and the late Jean-Pierre Cassel was enlisted. In a role originally slated for Johnny Depp, Mr. Amalric deftly elicits the striking contrast between the healthy Bauby who appears in the film’s many flashbacks and fantasies, and the silent effigy he became. “I forgot that he could move,” Mr. Schnabel said of the relatively unknown 41-year-old actor. “The self-control was extraordinary.”

But the real scene-stealer is the great Max von Sydow, who plays Bauby’s father. The film’s most drawn-out scene — and one of its finest — has him being shaved by his son, shortly before the stroke. Later, too infirm to leave his Paris apartment, he calls his son’s hospital room and comes undone on the phone, disconsolate that they are now both prisoners of ruined bodies.

In this scene and others, one can see that the director’s heart is in it. And if Mr. Schnabel is proud of his stirring exploration of mortality, he has a right to be. “Probably if I was French I would have won the Palme d’Or,” he said, referring to the top prize at Cannes. He didn’t appear to be joking.