THE view of the future offered by Ridley Scott's muddled yet mesmerizing ''Blade Runner'' is as intricately detailed as anything a science-fiction film has yet envisioned. The year is 2019, the place Los Angeles, the landscape garish but bleak. The city is a canyon bounded by industrial towers, some of which belch fire. Advertising billboards, which are everywhere, now feature lifelike electronic people who are the size of giants. The police cruise both horizontally and vertically on their patrol routes, but there is seldom anyone to arrest, because the place is much emptier than it used to be. In an age of space travel, anyone with the wherewithal has presumably gone away. Only the dregs remain.

''Blade Runner'' begins with a stunning shot of this futuristic city, accompanied by the rumbling of Vangelis's eerie, highly effective score. It proceeds to tell the story of Rick Deckard and his battle with the replicants, a story based on Philip K. Dick's novel ''Do Androids Dream of Electric Sheep?'' In brief: replicants are manmade creatures that possess all human attributes except feelings. They have been built to serve as slaves in Earth colonies that are Off World, i.e., elsewhere. Whenever the replicants rebel, the job of eliminating them is given to a special, skilled hunter. This expert is called a blade runner.

Rick Deckard is the best of the blade runners, now retired. He is as hard-boiled as any film noir detective, with much the same world view. So when he is told, at the beginning of ''Blade Runner,'' that an especially dangerous group of replicants is on the loose, and is offered the job of hunting them, he can't say no. Even in the murkiest reaches of science-fiction lore, a man's gotta do what a man's gotta do.

''Blade Runner,'' which opens today at the Criterion Center and other theaters, follows Deckard's love affair with a beautiful replicant named Rachael, who is special assistant to the high-level industrialist who created her. It also follows Deckard's tracking down of the runaways, most notably their white-haired, demoniclooking leader, Batty (Rutger Hauer). These events involve quite a bit of plot, but they're nothing in the movie's excessively busy overall scheme. ''Blade Runner'' is crammed to the gills with much more information than it can hold.