What do you do if you want to import a part into SolidWorks that is difficult to define parametrically? Solidworks has come up with a great tool to utilize images where users are able to import a variety of files into a part file.
Insert an Image:
To get an image file (.bmp, .jpeg, .gif, etc) you will need to open a sketch then go to Tools, Sketch Tools, Sketch Picture. This will send you to browse for the image file. Once in the sketch you can change the size or angle. If you need to re-size after insertion, simply double-click the edge of the image while you are in edit sketch mode.
(Caution: this will display in parts or assemblies (as long as the sketch is shown) but will not display in drawing views in versions before 2010.)
When exactly is this tool useful?
The tool can be used when attempting to recreate a real part in SolidWorks, especially parts with complex curvature or organic shapes when a high level of accuracy is not needed. You can perform the above-mentioned steps to insert and place your image, then use a variety of sketch tools to recreate a silhouette profile of the part. From the profile, you will be able to create solid bodies that are generally more accurate than the "eyeball-ing it" method. Below is an example of doing exactly this after using the sketch image tool.
Sketch started by tracing an image with the spline tool: