Why does Exporting Document to JPEG using ArcObjects in Layout View result in bad picture quality?

Question

I want to export the Active View with ArcObjects to JPEG. All Layers in the Document are raster layers (GeoTiff).

I use this code which works quite well when in Data View, but when I perform the same export in Layout View, the picture quality is really bad.

Has anyone an idea what the cause of this problem could be?

If I do File -> Export Map picture quality is good in both Data and Layout View. So Esri seems to be doing it differently in ArcMap.

EDIT: kenbuja had the answer. In case somebody needs the C# variant of the method he mentioned, have a look at the esri documentation

Answer 1

Try setting the output image quality, calling the following subroutine. The iResampleRatio is an value between 1 and 5, with 1 being the highest quality. These correspond with the settings on the export dialog's "output image quality" for vector exports. For image exports, you should always set output image quality to 1 (best).

Private Sub SetOutputQuality(ByVal iResampleRatio As Long)
    Dim pOutputRasterSettings As ESRI.ArcGIS.Display.IOutputRasterSettings = pActiveView.ScreenDisplay.DisplayTransformation
    Dim pGraphicsContainer As ESRI.ArcGIS.Carto.IGraphicsContainer
    Dim pElement As ESRI.ArcGIS.Carto.IElement
    Dim pMapFrame As ESRI.ArcGIS.Carto.IMapFrame
    Dim pTmpActiveView As ESRI.ArcGIS.Carto.IActiveView

    pOutputRasterSettings.ResampleRatio = iResampleRatio

    If TypeOf pActiveView Is ESRI.ArcGIS.Carto.IPageLayout Then

      'assign ResampleRatio to the Maps in the PageLayout
      pGraphicsContainer = pActiveView
      pGraphicsContainer.Reset()
      pElement = pGraphicsContainer.Next
      Do While Not pElement Is Nothing
        If TypeOf pElement Is ESRI.ArcGIS.Carto.IMapFrame Then
          pMapFrame = pElement
          pTmpActiveView = pMapFrame.Map
          pOutputRasterSettings = pTmpActiveView.ScreenDisplay.DisplayTransformation
          pOutputRasterSettings.ResampleRatio = iResampleRatio
        End If

        pElement = pGraphicsContainer.Next
      Loop
    End If
End Sub