Six or seven hours into a shift, just how carefully can a security guard watch a static row of video monitors? Clara Conti is sure that even the most diligent watchdog might doze a bit from the monotony.

Conti's company, ObjectVideo, based in Reston, sells software that allows video surveillance cameras to detect motion in unauthorized areas and automatically trigger alarm systems.

"People who have to watch all the monitors are often bored to tears, drinking coffee 24/7," Conti said. "The human attention span for watching video surveillance just isn't there; it's too low."

ObjectVideo's system is based on technology developed by researchers at the Defense Advanced Research Projects Agency. In early 1998 Bob Douglass founded DiamondBack Vision to apply the research to streaming video products.

The company was quick to develop products, but buyers were hard to find. In August 2001, the firm switched its name to ObjectVideo and changed its focus to the security sector.

Conti joined the firm soon after its transformation and, after working to conserve cash through layoffs and office closures, led the company through a second product-development phase.

Today ObjectVideo is back in sales mode, pitching its products to organizations with large security needs, including airports, power plants, government building and oil refineries. The product works by connecting existing video cameras to ObjectVideo software that identifies suspicious movements.

Craig Heartwell and Clara Conti, executive vice president and chief executive, respectively, of ObjectVideo sell the company's video surveillance software in the security sector.