Tweak to get the perfect trace
Table of Contents
Adjusting the Vector Trace Settings
The Trace Settings found on the right side of the Tracing Options dialog apply to the actual tracing of the image and determine how the final vector paths are drawn.
- Fills. When you have Fills selected, Live Trace creates closed and filled vector paths for all resulting vector objects. Fill tracing produces results that more closely match the original image, including variable-width lines that are common in marker or ink renderings (Figure 4). Fill tracing also results in more complex vectors because it needs more anchor points.
Figure 4: When you choose the Fills setting, the traced paths appear with thick and thin edges, closely matching the original image.
- Strokes. With the Strokes setting selected, Live Trace creates stroked open paths for all areas that fall within the Max Stroke Weight setting. Areas that exceed this setting result in unfilled areas outlined with a 1-point stroke. Stroke tracing results in paths with fewer anchor points (Figure 5).
Figure 5: When you choose the Strokes setting, the traced paths appear consistent and results in a less complex traced image overall.
- Max Stroke Weight. The Max Stroke Weight setting determines the heaviest stroke weight Live Trace can use when tracing the image. This setting is only available when the Strokes trace setting is used.
- Min Stroke Length. The Min Stroke Length setting determines the shortest path that Live Trace can use when tracing the image. This setting is only available when the Strokes trace setting is used.
- Path Fitting. Path Fitting determines how closely Live Trace follows the shape of the original raster image. A lower Path Fitting setting results in paths that closely match the original raster image, yet might also reveal imperfections or irregular paths that aren’t smooth. A higher setting produces smoother paths with fewer anchor points but might not match the raster image as closely (Figure 6).
- Minimum Area. The Minimum Area setting sets a threshold for how large a section of the raster image has to be in order to traced into a vector object. By setting a minimum area, you can have Live Trace only trace areas of pixels that meet a minimum size. For example, if the Minimum Area is set to 9 pixels, Live Trace ignores regions of pixels that are less than 3 by 3 pixels in size.
- Corner Angle. The Corner Angle setting defines the sharpness of the angles used in the resulting vector objects. This setting is measured in degrees, not pixels. If you think of 0 degrees as perfectly flat and 180 degrees as a hard corner (rather than a rounded one), anything sharper than the Corner Angle setting (the default is 20) is converted to a corner anchor point rather than a smooth anchor point.
Figure 6: This figure shows examples of a variety of path fitting settings for the same image. Notice how the paths get smoother as the number is increased but that the result doesn’t match the original sketch as much.
Where to go from here
For more information about Live Trace, check out the following resources:
- Liven up projects with Live Trace and Live Paint by Total Training
- Creating Vector Content Using Live Trace (PDF, [an error occurred while processing this directive]) by the experts at Adobe
- Turn bitmap images into editable vector art in seconds (PDF, 117K) by the experts at Adobe
