How to project a raster with a datum transformation

public static void ProjectRasterWithDatumTransformation(IRasterDataset2
    rasterDataset, ISpatialReference outSR, esriSRGeoTransformation2Type geoTrans)
{
    //This example shows how to specify a datum transformation when projecting raster data.
    //rasterDataset—Represents input of a raster dataset that has a known spatial reference.
    //outSR—Represents the spatial reference of the output raster dataset.
    //geoTrans—Represents the geotransformation between the input and output spatial reference.
    //Set output spatial reference.

    IRaster raster = rasterDataset.CreateFullRaster();
    IRasterProps rasterProps = (IRasterProps)raster;
    rasterProps.SpatialReference = outSR;

    //Specify the geotransformation.
    ISpatialReferenceFactory2 srFactory = new SpatialReferenceEnvironmentClass();
    IGeoTransformation geoTransformation = (IGeoTransformation)
        srFactory.CreateGeoTransformation((int)geoTrans);

    //Add to the geotransformation operation set.
    IGeoTransformationOperationSet operationSet = new
        GeoTransformationOperationSetClass();
    operationSet.Set(esriTransformDirection.esriTransformForward, geoTransformation);
    operationSet.Set(esriTransformDirection.esriTransformReverse, geoTransformation);

    //Set the geotransformation on the raster.
    IRaster2 raster2 = (IRaster2)raster;
    raster2.GeoTransformations = operationSet;

    //Save the result.
    ISaveAs saveas = (ISaveAs)raster;
    saveas.SaveAs(@"c:\temp\outputRaster.img", null, "IMAGINE Image");
}

Public Sub ProjectRasterWithDatumTransformation(ByVal rasterDataset As IRasterDataset2, ByVal outSR As ISpatialReference, ByVal geoTrans As esriSRGeoTransformation2Type)
    
    'This example shows how to specify a datum transformation when projecting raster data.
    'rasterDataset—Represents input of a raster dataset that has a known spatial reference.
    'outSR—Represents the spatial reference of the output raster dataset.
    'geoTrans—Represents the geotransformation between the input and output spatial reference.
    
    'Set output spatial reference.
    Dim raster As IRaster = rasterDataset.CreateFullRaster()
    Dim rasterProps As IRasterProps = CType(raster, IRasterProps)
    rasterProps.SpatialReference = outSR
    
    'Specify the geotransformation.
    Dim srFactory As ISpatialReferenceFactory2 = New SpatialReferenceEnvironmentClass()
    Dim geoTransformation As IGeoTransformation = CType(srFactory.CreateGeoTransformation(CType(geoTrans, Integer)), IGeoTransformation)
    
    'Add to the geotransformation operation set.
    Dim operationSet As IGeoTransformationOperationSet = New GeoTransformationOperationSetClass()
    operationSet.Set(esriTransformDirection.esriTransformForward, geoTransformation)
    operationSet.Set(esriTransformDirection.esriTransformReverse, geoTransformation)
    
    'Set the geotransformation on the raster.
    Dim raster2 As IRaster2 = CType(raster, IRaster2)
    raster2.GeoTransformations = operationSet
    
    'Save the result.
    Dim saveas As ISaveAs = CType(raster, ISaveAs)
    saveas.SaveAs("c:\temp\outputRaster.img", Nothing, "IMAGINE Image")
    
End Sub