A few digital projectors can make a big impression, beaming presentations or advertisements onto entire walls. But making their images seamless requires costly and time-consuming calibration of fixed projectors. Researchers at Mitsubishi Electric Research Laboratories in Cambridge, MA, have devised a way to do the same job in 10 seconds with software and a cheap camera-say, a Web camera-enabling portable, lower-cost systems. First, several projectors are placed in roughly the right places, each beaming a checkerboard pattern onto the wall. The camera registers the relative alignment of these displayed grids. Finally, software alters each projector’s image fragment-twisting, rotating or bending it as needed-so that the full image appears seamless. Such units could be used in stores, offices or even homes, where “any wall can become a projection TV,” says system designer Ramesh Raskar, a computer scientist at Mitsubishi, who adds that the system should reach market within two years.