Louis Malle's "Pretty Baby" is likely to achieve a lasting fame, even if it disappoints many people primed for a more dramatic or merely sensational approach to the subject of child prostitution. The film is distinguished by a remarkable pictorial evocation of a very special sort of exotic, corrupt setting - a fashionable New Orleans bordello, circa 1971 - and by a remarkable new personality: 12-year-old Brooke Shields, an exceptionally beautiful and animated juvenile actress who makes one of the most astonishing debuts in movie history.

"Pretty Baby," which opens today at the K-B Cerberua and Janus, as historical study of the legendary red-light district of New Orleans. Rose drew on the recollections of several former prostitutes. One of them, called Violet, was evidently the protype for the Violet of the film, a prostitute's daughter who has been bron and raised in a bordello and becomes a child prostitute as a matter of course.

An impressive movie of a highly specialized kind, "Pretty Baby" may appear fundamentally distasteful to people who doubt (with some justification) that an environment like the one that nurtures and exploits Violet can or should be represented on screen. At the same time, Malle has evolved into such a pensive, impressionistic director that his very discretion within indiscreet surroundings may alienate segments of his potential audience.

"Pretty Baby" has the virtues of a haunting, suggestive short story. For my taste it's also as erotically suggesive as it needs to be. I can't imagine how it would have helped Malle to heat up either the imagery or the scenario. If anything, he makes more trouble for himself attempting to dramatize the material than declining to dramatize it. Viewed more or less throught the eyes of Violet, an exquisite but ignorant and impetuous child destined to come of age in a brothel, the movie seems sensuously evocative and psychologically disturbing.

The least effective aspect of the movie is the resort to an indecisive Lolita-Humbert relationship between Violet and a character based on the obsure portrait photographer E. J. Bellocq, whose fame rests on a collection of photos of Storyville prostitutes discovered after his death. As the Bellocq figure, Keith Carradine never becomes an organic part of the picture. He's an outsider in a truly superfluous sense of the term, a flop as both a principal character and a stand-in for the filmmaker.

Malle and Polly Platt, who collaborated on the script, might have developed the relationship of the girl and the photographer dramatically. It appears that they weren't prepared to but probably got nervous about organizing the scenario in a consistently impressionistic way. The result is a half-baked, wavering style of exposition. To function at all, the Carradine character needs to be more active and impassioned. When he ultimately takes Violet as a child bride, the potential for disaster in their absurd marriage cries out to be recognized and exploited in some dramatically logical fashion.

Malle would have been better off trusting completely in the ecovative power of the brothel setting and its implications for a child immersed in that setting. Violet's situation seems fundameentally upsetting, and Brooke Shields' precocious beauty and emotional intensity enhance whatever shameful fascination one feels about the character.

Despite its shocking aspects, "Pretty baby" belongs to the tradition of movies like "The Fallen Idol," "The Rocking Horse Winner," "A Kid for Two Farthings," "Tiger Bay," and Malle's own "Zazie" and "Lanxombe, Lucien," in which the adult world is perceive and often misapprehended by a child. Inserting Bellocq as a suitor for Violet blurs the focus that Malle had seemed to establish sharply when using the child as our guide to this vanished decadent milieu. It also leads one to expect a measure of dramatic development that Malle is either disinclined or unable to provide.

The affinities between "Pretty Baby" and "Lancombe, Lucien," a curiously clinical study of a French peasant boy who joins a collaborationist group in the final months of the German Occupation, are especially pronounced. Violet seems a pet of thewhores and their clientele in the same way that Lucien became a pet of the collaborationists. Malle even identifies both characters visually with pet animals - Violet with a cat in a sublime little scene where she shares breakfast with the animal and Lucien with big hunting dogs.

Even the decadence of the brothel setting is anticipated by the hotel in "Lancombe, Lucien" where the collaborationists hang out. Each community is living out the sheltered form ot corrupt self-indulgence and exploitation whose social protectuin is about to end. The Liberation dooms the closed circle. Lucien has joined. The brothels of Storyville are closed in 1917 as a consequence of social pressure stemming from wartime piety.

In short, Violet's world is as severely circumscribed as Lucien's. In her case, home happens to be a whorehouse. She is constantly exposed to primal scenes, many of them involving her mother (very well played by Susan Sarandon, who seems to have bounced back from whatever ailed her in "The Other Side of Midnight"), who remains as much of a child, emotionally, as Violet. In an early petulant outburst, the mother, called Hattie, complains, "If it weren't for you, I'd have been out of here." Why does everyone else get everything they want?" Later, Violent reenacts this scene with her doll, taking the role of mama herself.

Malle's most forcefull dramatic element is the feeling of rivalry and resentment that exists between mother and child without the characters being conscious of it. The script is eloquently supplied with scenes illustration this fundamental conflict and bond. As a result, the sight of Violet scheming to match or supplant Hattie as the reigning prima donna on the premises gives one a particularly awful sense of the willies. But in this context how can their rivalry be expressed in any way that isn't preverse? The business of the house is sexual gratification and as far as Violet can see, becoming the most brazen and desired sex object in the house is the surest source of self-esteem and self-realization.

Sven Nykvist's lighting reflects an extraordinarily rich and sensuous appreciation of colors, textures and fabrics in virtually every composition. However, no camera subject transfixes his lenses quite as powerfully as the face of Brooke Shields. With her dimpled chin, full lips and dark, heavily browed, flashing eyes, she projects and image as stunning as those of Elizabeth Taplor and Jean Simmons in their pubescent debuts.

Since Shields has been a photographic model since the age of 11 months, her facial affinity for the camera does not come as a surprise, although her aura does seem to be intensified by the motion-picture image. The surprising aspect of her talent is the range and intensity of her emotions. Obviously, she will need to transcend the disreputable connotations attached to her role in "Pretty Baby," but she may have the beauty and skill necessary to do it. It would be appalling to see her duplicate the career Linda Blair had in the aftermath of "The Exorcist."

"Pretty Baby" is Malle's first American production, and it's interesting to see how a foreign director responds on alien soil. The language seems to cause him more technical problems than anything else: The cadences and inflections are sometimes off, slightly but perceptibly.

On the other hand, Malle seems very assured with the casting, the period details and the social undercurrents. Some of the supporting players are marvelously effective, notably Frances Faye as a madame, Diana Scarwid as a sardonic whore with a German accent and Antonio Fargas as a piano player inspired to some extent by Jelly Roll Morton. Fargas' grave, sharply chiseled face proves an especially expressive instrument for registering the disgust of dignified blacks compelled to make their living among decadent, imperious white folk.

The failure to resolve a story decisively, however, invariably produces an emotional letdown. It also can degenerate into another kind of arbitrary bad habit. "Pretty Baby" ends ambigously, and I'm sure Malle feels that it should end that way, without our knowing whether Violet will meet a banal or drastic fate.

His refusal to speculate beyond a certain point may seem admirably modest if you're inclined to sympathize or unforgivably unimaginative if you're not. The speculation shifts from character to actress. At the end of "Pretty Baby" you're more intrigued by what the future holds for Brooke Shields than what it held Violet.