I've got some data from "http://srtm.csi.cgiar.org/SELECTION/inputCoord.asp" and it is in *.asc form. To process them I need to convert them to shapefile (need to merge them all into one shapefile and add attribute table, on and on ...), but I don't know how. Some web sites such as "http://converter.mygeodata.eu/ " do convert my data but I'm talking about 2.5 GB of data and it is impossible for me to upload this much data ... how can I convert them inside QGIS or ArcGIS ??? Is there another software that can convert my *.asc file into *.shp ??? A lot of thanks
You can try the GDAL utility gdal_polygonize.py. For example, to create a shapefile output.shp from input.asc:
gdal_polygonize.py -f "ESRI Shapefile" input.asc output.shp
Prerequisites: GDAL, Python and GDAL Python bindings.
But... Are you sure that SHP is the right format in order to work with such huge data?
Like @afalciano, I am not sure that you would want to convert this into a shapefile but if you do then the Raster To Polygon tool does that.