If you don't need to keep the image around, it is better to simply link to the file.
Convert to Path
Inkscape includes a tool to convert the bitmap automatically to a path (Tracing Bitmaps)
Path > Trace BitMap
Each trace creates one path and each path is made up of many sub-paths.
- A Scans property set to three will give three regions
- Smooth will smooth the bitmap prior to tracing.
- Stack Scans generate paths for mutually exclusive areas or that include all darker regions.
- The Suppress speckles option allows the automatic suppression of paths smaller than the specified size.
- Optimize paths boxes will result in less node
- Smooth Corners will result in less node
It is easier to clean up a tracing by converting the sub-paths into independent paths. (Path → Break Apart Shift+Ctrl+K)