What are some alternatives?
When comparing R2V and Inkscape, you can also consider the following products
CR8tracer - Convert bitmap images into monochrome vector formats
Sketch - Professional digital design for Mac.
Wintopo - High quality raster to vector conversion tool
Adobe Photoshop - Adobe Photoshop is a webtop application for editing images and photos online.
Ras2Vec - Raster to vector conversion program for Windows 95/98/NT
Affinity Designer - Professional creative software, exclusively for Mac.