[GIS] How to georeference a raster based on identical, already georeferenced raster

arcgis-10.0georeferencingmodelbuilderraster

I have two identical rasters, one has been georeferenced, the other has not. I would like to georeference the second raster automatically using the first one. I do not want to create links by hand and the raster has been warped so simply shifting xy position does not work.

Let me know if you have any ideas… most comfortable working in model builder but would love any solution.

Thanks!

Best Answer

If they are exactly identical and one has a world file (.tfw) you could copy and rename the file to match the basename of the other raster. If the cell sizes are different or if it is in another format you may have a trickier time of it.

Related Solutions

Raster Calculator Expressions – Creating Dynamic Map Algebra Expressions in Raster Calculator

I've accomplished this in .NET by declaring optional inputs and then using an IF statement to decide whether or not to add additional rasters.

      Public Function CalculateMapAlgebra(ByVal sMapAlgebra As String, ByVal R1 As IGeoDataset, Optional ByVal R2 As IGeoDataset = Nothing, Optional ByVal R3 As IGeoDataset = Nothing) As IRaster
.
.
.
.
            'Bind a raster
            pMapAlgebraOp.BindRaster(R1, "R1")
        If Not R2 Is Nothing Then
            pMapAlgebraOp.BindRaster(R2, "R2")
        End If

        If Not R3 Is Nothing Then
            pMapAlgebraOp.BindRaster(R3, "R3")
        End If

        Dim rasOut As IRaster = pMapAlgebraOp.Execute(sMapAlgebra)

        return rasOut

End Function

You have to do some fiddling with the input Map Algebra string (sMapAlgebra in my example) so that the optional parameters are either included or excluded. I do this outside of the method above, but you could create the string based on the IF statement. If you have a known limit to the number of input rasters (e.g. 3) you could just create 3 possible strings and choose one based on the number of actual parameters. However, this solution becomes bulky if you have many (say... > 10) possible input rasters.

In the same way you could determine the number of output parameters (e.g. IF you have 3 input rasters create 3 associated output rasters, maybe by appending "out" to the raster name, e.g. "R1_out" in my example. You could just create these inside of the conditional statement.

[GIS] How to digitize polygons from georeferenced raster file

What you could do is:

In the original image, fill each area with a unique color, e.g. with Gimp
Georeference
Run Raster to Vector
Clean up the polygon geometries manually

Best Answer

Related Solutions

Raster Calculator Expressions – Creating Dynamic Map Algebra Expressions in Raster Calculator

[GIS] How to digitize polygons from georeferenced raster file

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