At Adobe, the job of integrating a prototype into an application falls to a “feature team.” Such teams are composed of engineers, marketing experts, user interface designers, and a group of power users known as quality engineers. Together, they try to figure out the best way to implement the raw technology.
In this case, the team realized that different users want different things from a trace. A mapmaker wants editable lines, while a cartoonist wants something that’s simple to use but faithfully represents a sketch. Luckily, the Live Trace engine is very flexible. Depending on the data that enters the tool and the parameters set for it, the same bitmap image can produce entirely different kinds of vector traces.
To cover all possibilities, the feature team devised a powerful interface and workflow. First, users are given a selection of presets that let them generate a useful trace based either on the original image (B&W, grayscale, color) or the final result (comic art, technical drawing, and so on). From there, they can modify the settings to refine the trace. But most importantly, they can do it all on the fly.
“We came up with a notion of a live trace,” Dave Holloway, lead computer scientist on the feature team, explains. “Typically in other programs, you hit a button, it traces, and you’re done.”
Whenever you trace an image, Live Trace creates something called a “tracing object.” As you work in the Tracing Options dialog box, you can change the number of colors selected, tighten up or loosen curves, or edit the original in Photoshop software while tracing (note that live editing in Photoshop only works when you Place-Link the image). The key is to play with the options until you get something you like. “I think the goal for users is to continue to push the boundary of the tool until they make it work right for them,” says Skirko.
Looking at all of the different ways you can improve your trace, Skirko believes the most important is the “sampling,” or resolution, of the image. He advises making sure you bring an image into Illustrator at the highest resolution possible. Then, trace it on a high resolution and slowly downsample until you get the look you want. “Usually, there is a happy medium somewhere,” he says. You’ll also find that you get faster tracing performance as you downsample, as this action results in a less complex image to analyze.
Try it: