Business Notes ADVERTISING

Mammoth billboard images of the kind that frequently adorn Manhattan's Times Square have been a frustrating market niche for the $1.3 billion outdoor advertising industry. The huge, hand-painted icons often take a month to produce, sometimes depict faces inaccurately, and can be awkward to move. But now two California manufacturers have shown that turning out big pictures can be child's play. Los Angeles-based Metromedia Technologies uses computers to convert photos or other artwork into billboards up to 17 ft. by 54 ft. within just six hours. Another company, Torrance-based Computer Image Systems, is creating a 41-ft. portrait of Liza Minnelli that will rise this week over New York's Palace Theater.