If you were to learn that Disney+, from the company that owns the work created by the late Jim Henson, was broadcasting a documentary about the visionary puppeteer and filmmaker and that doc was being directed by Ron Howard with substantial input from Henson’s family, you could probably guess what the movie would be like.

And you’d be right.

In this case, though, there’s nothing wrong with a little predictability. Henson and Howard are a fine match, and the sort of film you’d expect Ron Howard to make – straightforward, skillful, honest and sympathetic – is pretty much the kind of movie you’d want about Jim Henson.

There are surprises in “Jim Henson Idea Man,” which had its world premiere on Saturday night in the Cannes Classics section of the Cannes Film Festival. But there’s nothing shocking, nothing earthshaking about this portrait of the man who gave us Big Bird, Kermit the Frog, Miss Piggy, Bert and Ernie, “Fraggle Rock,” “Dark Crystal” and, oh yeah, David Bowie and a 14-year-old Jennifer Connelly in “Labyrinth.”

Henson wasn’t the kind of mad genius who would make for a wild documentary; he was a quiet man who pushed himself and sometimes others too hard while leaving a profoundly good mark on children’s entertainment and much more. He was the kind of man, in short, who warrants a doc by Howard, who in recent years has made a series of exemplary nonfiction films about figures in the world of entertainment and culture (“The Beatles: Eight Days a Week,” “Pavarotti,” “We Feed People”…)

“Jim Henson Idea Man” relies on a mixture of archival footage and talking heads – either close collaborators like Frank Oz or Henson’s children, all of them involved to some degree in his work). But it has a style seemingly inspired by Henson’s own early short films, before he landed on “Sesame Street” and changed his and our lives: quick images, manic cuts, bursts of animation and graphics. The central conceit puts all the interview subjects in a space defined by gray cubes that can move or turn into screens, and it works without being too distracting.

The trick, though, isn’t to come up with an arresting visual style; it’s to provide insight into a man of whom Frank Oz, his longtime collaborator and close friend (and Bert to Henson’s Ernie) said, “He was so internal and quiet that his inner life must have been sparkling.”

Given Henson’s death at the age of 53 in 1990 of complications from untreated pneumonia, he’s not around to offer any of his own insight into that sparkling inner life, even if he had been so inclined. So Howard is left delving into the work and the outer life, and finding clues to the inner life from many of those closest to Henson.

His journey was an unlikely one, because Henson got into puppeteering not because it was a passion, but because he wanted to be in the television business and thought that could be a way in. It was, and Henson even won a local Emmy in Washington, D.C. in 1959, receiving it from Richard Nixon, of all people. (According to the film, Nixon took one look at the hirsute Henson, who’d grown a beard to hide his acne scars, and awkwardly commented, “I knew a man in the Navy with a beard.”)His journey was an unlikely one, because Henson got into puppeteering not because it was a passion, but because he wanted to be in the television business and thought that could be a way in. It was, and Henson even won a local Emmy in Washington, D.C. in 1959, receiving it from Richard Nixon, of all people. (According to the film, Nixon took one look at the hirsute Henson, who’d grown a beard to hide his acne scars, and awkwardly commented, “I knew a man in the Navy with a beard.”)

Henson had created the Muppets by then, but those soon-to-be-immortal characters didn’t get their true spotlight until 1969, when Children’s Television Workshop recruited him for a new show called “Sesame Street.” Henson had wanted to get into the nightclub business with a multi-media, graphics-heavy joint called Cyclia instead, but was persuaded to come on board the new show that was being designed to both appeal to kids and teach them things. (“Whew,” says one of Henson’s daughters in the film.)

Behind-the-scenes footage from “Sesame Street” is priceless, with Henson, Oz and other puppeteers contorting and twisting themselves to be invisible to cameras, and invisible to the kids whose lives they really were changing. Still, the show’s success was disorienting to Henson and got in the way of his plans to do Broadway shows, amusement parks and all sort of other things. He tried to give his creations a life in primetime by pitching “The Muppet Show,” but every American network passed – though NBC did give the Muppets segments on the first season of “Saturday Night Live,” where Henson and crew weren’t allowed to write their own material. That came from “SNL” writers like Michael O’Donoghue, who said he “hated writing for felt.”

Still, British mogul Lew Grade understood and gave Henson a deal for 25 episodes of “The Muppet Show,” which became a huge worldwide hit, attracted the biggest stars in the world to be the one token human in each episode and spawned a movie franchise as well.

Rita Moreno, one of the guests, details her struggles to get through a song surrounded by Muppets without breaking into laughter – but she reserves her most heartfelt comments for the message sent by Henson’s rendition, as Kermit, of the gentle hymn to tolerance, “Green.” “It’s not easy being green,” she says quoting the song’s opening line. “We all know what that means.”

Things weren’t as successful when Henson ended “The Muppet Show” after five seasons; he had to rewrite the script and redub “The Dark Crystal” twice after it had been filmed; he got a divorce; and he was hit hard by the commercial and critical failure of the elaborate fantasy “The Labyrinth.” In a way, the struggles give Howard more to work with than the successes, and the small insights into the collaboration and the differences between Henson and his wife, Jane, are a sign that a doc can be authorized without being sanitized.

“Jim Henson Idea Man” is likely to be as honest a portrait as you’ll get of the man who never set out to be a children’s entertainer but ended up as one of the greatest. If at times it gets a little tiring hearing yet another person sing Henson’s praises, there’s never a feeling that the filmmakers are glossing over unpleasantries or trying to polish his image, and anyone who grew up with Henson’s creations will find it hard to begrudge all that praise.

In the line waiting to get into the Cannes premiere, a woman behind me told a friend, “If they sing ‘The Rainbow Connection,’ I’m gonna cry.” That touching song does appear in the film – and while I didn’t track her down to see if she’d cried at the end of the screening, my guess would be that tears were shed. But maybe they came not for “Rainbow Connection,” but for a killer version of “Green” performed by Big Bird at Henson’s funeral.

You won’t get that in any other Cannes movie this year.