Exporting JPW or GeoTiff - VB.Net

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01-08-2014 08:57 PM
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New Contributor III
Hi,

I am not sure if this is the correct location for this query, but here it is.
I am trying to export data from the data view in ArcMap to a georeferenced JPG or Tiff.
I can do it manually, however I would like to automate the process to export based upon a polygon layer.

I have been able to get the code working, however, the coordinates of the exported raster (Tiff) have not been preserved.
Could someone please point me in a direction of some documentation of how best to do this?

Please find my code below:

I know its a little rough, its a work in progress I have found some examples online have have spliced things together as I see it could work.

Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        Dim pEFeat As IEnumFeature
        Dim papp As IApplication
        Dim pmxdoc As IMxDocument
        Dim pmap As IMap
        Dim pFLayer As IFeatureLayer
        Dim pFClass As IFeatureClass

        papp = My.ArcMap.Application

        pmxdoc = papp.Document

        pmap = pmxdoc.FocusMap

        pFLayer = pmxdoc.SelectedItem

        pFClass = pFLayer.FeatureClass

        Dim pFCursor As IFeatureCursor
        pFCursor = pFLayer.Search(Nothing, False)

        Dim pFeature As IFeature
        pFeature = pFCursor.NextFeature


        Do While Not pFeature Is Nothing

          
            '******************************
            Dim MapSheet As String
            Dim BatchField As String
            Dim pfd As IFeatureLayerDefinition
            Dim pActiveView As IActiveView
            Dim pExporter As IExporter
            Dim pEnv As IEnvelope
            Dim exportFrame As tagRECT
            Dim pWorldFile As IWorldFileSettings
            Dim hdc As Long

            Dim pqfilter As IQueryFilter

            pfd = pmxdoc.SelectedLayer

            BatchField = "TAG"
            MapSheet = pFeature.Value(pFeature.Fields.FindField("TAG")) 'pFLayer.value(pFLayer.fields.findfield("MAPSHEET"))

            pfd.DefinitionExpression = BatchField & " = '" & MapSheet & "'"

            pFClass = pFLayer.FeatureClass
            pqfilter = New QueryFilter
            pqfilter.WhereClause = BatchField & " = '" & MapSheet & "'"

            ' pFCursor = pFClass.Search(pqfilter, False)

            pmxdoc.ActiveView.Extent = pFeature.Shape.Envelope
            pmxdoc.FocusMap.MapScale = 30000
            pmxdoc.ActiveView.Refresh()

            'Export the view
            pActiveView = pmxdoc.ActiveView
            pExporter = New TiffExporter
            pEnv = New Envelope
          
            Dim BEnv As IEnvelope

            BEnv = pmxdoc.ActiveView.Extent

            'Setup the exporter
            exportFrame = pActiveView.ExportFrame

            'pEnv.PutCoords(exportFrame.left, exportFrame.top, exportFrame.right, exportFrame.bottom) <--- Here the coords read 0 , 0 , 940 , 940 (not correct)

            pEnv.PutCoords(BEnv.XMin, BEnv.YMin, BEnv.XMax, BEnv.YMax) ' If I use this, I get a "NOT ENOUGH MEMORY ERROR" but the coordinates are correct

            Dim outloc As String = "C:\temp\"
            Dim out_prefix As String = "MapNumber"
            Dim dpi1 As Integer
            dpi1 = 800

            With pExporter
                .PixelBounds = pEnv
                .ExportFileName = outloc & "\" & MapSheet & out_prefix & ".tif"
                .Resolution = dpi1
            End With

            'Recalc the export frame to handle the increased number of pixels
            pEnv = pExporter.PixelBounds

            pWorldFile = pExporter
            pWorldFile.MapExtent = pEnv
            pWorldFile.OutputWorldFile = True


            hdc = pExporter.StartExporting
            pActiveView.Output(hdc, dpi1, exportFrame, Nothing, Nothing)
            pExporter.FinishExporting()

            pFeature = pFCursor.NextFeature ' pFCursor.NextFeature

        Loop

    End Sub


Regards,
K
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1 Reply
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New Contributor III
Good day,

So a follow-up to this post.
I got it working, it now exports a Geotiff to the correct spatial location.

Some of the fixes:

1) ensuring the map document was in a metre projetion
2) allowing for the export to take into account the DPI

My next issue is that the exported document is blank.
I am really unsure as to why this is.

If there are any insights...I would love to hear them...

Thanks
K
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