Reduced in resolution when converting from Visio to PDF in Visio 2013

Question

I have a .NET application that converts Visio files to PDF using the Document.ExportAsFixedFormat method. This works fine in Visio 2010. However, upon upgrading to Visio 2013, the exact same code is producing PDF with much lower resolution that is unsuitable
for print. I am not sure what is wrong. Is there something I can do to export high resolution PDF with Visio 2013? Thanks!
The following is my code:
_app.ActiveDocument.ExportAsFixedFormat(VisFixedFormatTypes.visFixedFormatPDF, // Format
pdfpath, // Output path
VisDocExIntent.visDocExIntentPrint, // Output quality
VisPrintOutRange.visPrintFromTo, // Range
1, // Start page
-1, // End page
false, // Color as black
true, // Include background
false, // Include document properties
false, // Indicate tag structure
true, // Use ISO 19005-1 (PDF/A).
System.Reflection.Missing.Value // FixedFormatExtClass

Answer 1

Hi Eugene
I am using visFixedFormatPDF, visDocExIntentPrint, and visPrintAll, but there is no improvement in the resolution of the PDF.
The Type.Missing value can only be used for the last parameter. The other parameters require either bool or int, so I get compile errors if I try to use Type.Missing.
I also notice the reduction of resolution in Visio 2013 only applies to bitmap images copied into the Visio file. Lines and shapes drawn in Visio still looks fine. I am getting this problem even if I simply select the Save As menu option and select PDF,
so this problem could be independent of office.interop.
Is there something I can do to avoid the degradation of resolution of bitmaps in Visio 2013? Everything is fine in Visio 2010.