2

I have question about QGIS. I have georeferenced a fairly complex geological map (raster file) and would like to vectorize the different geological units. However, the georeferenced map contains text, contour lines, rivers, etc. in addition to the geological units that I would like to convert to shapefiles. I have tried to polygonize the map in bulk, but the resultant Shapefile is too bogged down by the extraneous data that I have no interest in to make any sense of.

Do you have any suggestions of how I can more easily do this without manually tracing all of the boundaries?

I have attached an image of the geological map below to give you all a sense of what I'm dealing with.

enter image description here

TomazicM
  • 25,601
  • 22
  • 29
  • 39
user144380
  • 21
  • 1
  • You could try simplifying the image in an image editing program like photoshop, or if you are looking for something free krita or GIMP. By simplifying I mean removing the text or extra details that you don't want. – TJR Jun 10 '19 at 14:21
  • Check with Maarten de Wit, he has geological gis data available for the Weltevreden area https://doi.org/10.1016/j.gsf.2017.10.005 – Hans Erren Jun 10 '19 at 14:37
  • You'd approach this by trying to find some image processing operations that remove the things you don't need and enhance the things you do. For example a "despeckle" operation with a suitable threshold might remove the small text annotations. But I would say this was very hard. – Spacedman Jun 10 '19 at 14:51
  • May be this can help you https://gis.stackexchange.com/questions/68076/digitizing-raster-automatically – Gerardo Jimenez Jun 10 '19 at 16:57

0 Answers0