Friday, 20 May 2016

Getting polygons from PNG images for the QGIS Shapefiles


I would like to have ready polygons (borders) from some .PNG image and use them in QGIS as a shapefile.


My file looks like this:



enter image description here


which is crude raster PDF. My goal is to execute all borders (marked orange) as a simple shepefile polygons, as we know i.e from NUTS1 division.


I converted my PNG file into the vector graphic (SVG) image, thinking that it will be easier to save it in some format.


I used for this purpose the Inkspcape, where I selected option Path -> Trace Bitmap, and then selected colour threshold in order to distinguish these borders with the background. Unfortunately the names also came through, making whole graph difficult to manage.


enter image description here


I started to remove the names manually, but id doesn't make sense, since some of them are sticked to the borders and binded as one layer.


enter image description here


So now I need to find some way to quick separation of the names from the borders, and further I can think about geotagging this SVG graph in QGIS.


However I think, that maybe some less awkward and quicker option is available?


I found something here:



Convert PNG image to Shapefile in QGIS


https://www.safe.com/convert/png/arcgis-shp/


First one doesn't help a lot, and 2nd one requires bigger involvment, which probably is not for free.


I am aware of ready shp administrative (and other) databases, but in this event I need some own.


Is someone able to help?




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