SIOX means Simple Interactive Object Extraction. It lets you separate an object from the background in a bitmap image. If you paid close attention to the steps performed to do a trace in the previous section, you'll notice that the option to use this feature is within the Tracing Bitmap dialog box.
Using SIOX depends on the characteristics of the bitmap image. If you have a photograph where an object is clearly distinguished in color from the background—you have a great chance for success in recreating it with a trace using this feature. Here's how it's done: