"Passion d'Amore" sounds like a cheap perfume, and it is difficult to ignore the scent of rank melodrama when the plot of this curiously morbid costume romance begins decomposing in the closing stages. Nevertheless, it strikes a nerve or two and keeps them jangling before the miscalculations get out of hand.

Opening today at the K-B Janus, "Passion d'Amore" may serve as a sobering reminder that cliche's like "Beauty is only skin deep" and "Love conquers all" aren't prepared to deal with the emotional torment created by intense feelings of physical unattractiveness and romantic deprivation.

A French-Italian co-production, "Passion d'Amore" seems an uncharacteristic project for Ettore Scola, the Italian filmmaker best known for the marvelous, expansive social comedies "The Pizza Triangle" and "We All Loved Each Other So Much."

"Passion d'Amore" is set in a more remote past--a provincial garrison town in the 1860s--and depicts a much more corrosive and disturbing misalliance. Giorgio, a young cavalry officer romantically involved with a beautiful married woman in Turin, is posted to a remote command on the northern frontier.

Invited to share the officers' mess hosted by his commanding officer, Giorgio can't help noticing that one diner is conspicuously absent. He learns that this empty place belongs to the colonel's cousin, an unfortunate young woman named Fosca, who is in poor health and customarily prefers the solitude of her sickroom. As the colonel himself gravely remarks, "She stays in bed an average seven days a week." Equally sage, the local doctor observes that "She's so sick her body hasn't the strength to produce a fatal illness."

Sure enough, these deadpan teasers turn out to be self-deluding underestimations of the feverish, desperate personality smoldering upstairs at the colonel's residence. Eventually, the invalid reveals herself--inspired, as she breathlessly confides to the alarmed object of her devotion, by an overpowering attraction to Giorgio.

The superficial cause for alarm is her appearance: Gauntly unattractive, Fosca confronts the world with a jaggedly hooked and flattened nose and a protruding jaw and set of teeth. The facial effect is eerily cadaverous, and Fosca reinforces the mood by dressing in funereal brocades.

What's really alarming is the ruthless intensity of Fosca's passion, and it's this force that can't be repelled, no matter how repellent her facial configuration. The character recalls other fiercely neurotic, unloved movie heroines, notably Gloria Swanson in "Sunset Boulevard," Isabelle Adjani in "The Story of Adele H." and Olivia de Havilland in "The Heiress."

In Valeria D'Obici, Scola has a forceful leading lady for this perverse love story. What he lacks is a susceptible leading man. Bernard Giraudeau is a smoothly handsome washout as Giorgio. Evidently incapable of meeting the sort of emotional challenge that William Holden mastered opposite Swanson in "Sunset Boulevard," Giraudeau can't project the pity or guilt or fascination or weakness necessary to rationalize Fosca's ironic conquest of Giorgio.

D'Obici's incendiary, intimidating passion is muffled to some extent by Giraudeau's wet-blanket acting, as well as Scola's overemphasis on the masculine stuffiness of the provincial military society from which Fosca launches her romantic assault. In this setting her sexual hysteria is about the only sign of emotional vitality.

Despite the freakish aspects of Fosca, her unhappiness will no doubt stir familiar feelings of self-pity and remorse in most spectators. Who hasn't felt the humiliation of a romantic rejection or the bad conscience associated with evading an unwanted romantic overture? Perhaps everybody but Bernard Giraudeau, to the misfortune of his director.

Jean-Louis Trintignant, who might have done more for Giorgio not so long ago, turns up among the French auxiliary, playing the character role of the obtuse doctor, an assignment better suited to the portly Bernard Blier, who seems rather dubious and overaged as a gossipy major. Laura Antonelli plays Giorgio's mistress, an attraction guaranteed to mislead fans expecting the customary striptease. It's a minor role, with brief skin display.

It's also a psychological mystery in the last analysis, because nothing in the story explains the serenity with which Antonelli greets the news that her lover is being pressured by a madwoman: "Maybe it's a nobler love. She needs you. She needs you to survive." Suddenly deciding to break off the affair (had she been looking for an excuse all along?), she notes that, "Christmas is in a week. That's the gift I'll give my husband." Meaning herself rather than the holiday, probably. It's at this point that the plot starts throwing fits, so it might be wise to slip out and dream up a dramatic resolution of your own.