While not an open source or QGIS utility, ArcGIS does have the ArcScan extension that can be used to help vectorize features from raster maps. ArcScan, of course, works best with 2 color images and hard edges, so I'm uncertain how the multicolor raster you showed would work. While it is not perfect, it may be another potential option.

Starting with the release of ArcGIS 10.1, ArcScan for ArcGIS is included in all license levels of ArcGIS for Desktop software at no additional cost.

Of course, as @Peter Ivan suggested, you could always turn to a 3rd party vendors, like Amazon Mechnical Turk (see more generic details on wikipedia), to digitize the data for you.

While not an open source or QGIS utility, ArcGIS does have the ArcScan extension that can be used to help vectorize features from raster maps. ArcScan, of course, works best with 2 color images and hard edges, so I'm uncertain how the multicolor raster you showed would work. While it is not perfect, it may be another potential option.

Starting with the release of ArcGIS 10.1, ArcScan for ArcGIS is included in all license levels of ArcGIS for Desktop software at no additional cost.

Of course, as @Peter Ivan suggested, you could always turn to a 3rd party vendors, like Amazon Mechnical Turk (see more generic details as described by wikipedia), to digitize the data for you.