Working with Graphics - Adobe Illustrator CS6 on Demand - page 535

Change Image Tracing Options
Select the graphic that you want to trace.
• You can also select an image trace object to change it.
Click the Window menu, and then click Image Trace .
To view your changes as you set options, select the Preview check box.
Specify the following options:
• Mode. Click the list arrow to select a color mode.
• Palette. Click the list arrow to select a color palette.
• Colors, Grays, or Threshold. Drag the slider to adjust the range or intensity
of color.
To apply setting changes to the graphic, click Trace .