Cutting out white space

I have been looking for a way to cut out the bounds of my elevation data.  The file I am using is very odd shaped/fragmented at the borders.  When I run the elevation grid it comes back with data outside the bounds.  Is there a way to cut this off and make it be just withing the bounds of my data?

Thank you for all the help

Best Answer

  • sphillipssphillips Posts: 69
    Answer ✓
    I suppose a workaround would be to export to GeoTIFF with a white background and then use 'Create Area Features from Equal Values in Selected Layer' on the imported raster. Choose 'Only Create Areas for Selected Colors' and pick white. This will create polygons of the white areas. Just convert these to Line Features and delete the outer boundary and then convert back to Area Features. Now you can select a boundary to use as the Grid Bounds for the Gridding process or as a Cropping boundary (Right Click Layer > Options > Cropping).

    The whole thing took around 2 minutes on your image:



  • bmg_bobbmg_bob Global Mapper Programmer Posts: 1,726

    You don't indicate what version of Global Mapper you are using.  In v18, the Elevation Grid Creation Option screen contains a slider for Elevation Grid "No Data" Distance Criteria.  If you move that slider towards "Tight", you can get rid of the triangles outside the bounds.  You may need to experiment a bit to find the setting that works best for your data.

  • wagonersawagonersa Posts: 8
    I tried the first suggestion and it worked pretty well, but I like the geotiff idea.  Ill give that a shot, thanks!

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