There’s no question that engineers and creative pros look at the world through different eyes. Ask a designer to describe Adobe Illustrator CS2 software, and you’ll probably hear it’s a drawing program. Ask an Adobe engineer, and you might hear that Illustrator is a vector drawing application that collages, or stacks, individual shapes. Does it make a difference? Sometimes yes and sometimes no. But when it comes to the new Live Trace and Live Paint features, understanding the technology can help even a newbie work better.

Live Trace
Live Trace is no mystery to most Illustrator users. “It’s pretty easy to understand,” says Illustrator product manager Phil Guindi. “Essentially it takes raw bitmap data, whether it’s a photo or scanned drawing, and automatically turns it into vector data.”

Many tracing applications exist, but Live Trace aims to do the task better, and more conveniently. The tool has its origins in a prototype application built by Peter Skirko, a computer scientist in Adobe’s Office of Technology. In a nutshell, Skirko’s tool works by first reducing the number of colors in a bitmap image. It then draws vector paths to match the transitions between them.

Where Skirko’s tool really shines, however, is in the quality of paths it draws. Theoretically, a traced bitmap image can have only a few or thousands of individual curves. Skirko’s engine produces anchor points and curves that might have been created by a skilled Illustrator artist. For example, where other tracing technologies may use many points to define a curve, Live Trace may use only two, making the result more editable—and useful.

“If you do too little interpretation, the tool is not useful for the user,” he says. “But if you do too much on behalf of the user, you can get it wrong.”