Converting a Visio File to .png File

Hi!
It is difficult, because PNG is already well compressed, unlikely to be improved. You can compress it in JPG format.

If it would be helpful, I have macro code that I wrote years ago that saves each page of a Visio diagram as a png image. There are two variations: one that works on every Visio diagram in a directory and one that does that plus all the Visio diagrams in every subdirectory. Let me know whether you'd like either one.

Alex -- do you still need help with your question?

As the internet never sleeps, I'll add this article + code that I wrote many years ago:

Export All Pages in Document
http://www.visguy.com/2006/09/18/export-all-pages-in-document/

This will export an image with the last settings that the user set for image export in the current Visio session. Since the article was written, Visio has added some application settings that let you specify export settings without manually tweaking via the UI.

See the: Visio.Application.Settings.RasterExport___ methods.

Specific to this question:

Visio.Application.Settings.RasterExportDataCompression
Visio.Application.Settings.SetRasterExportResolution

And finally, see this article:
New Visio 2010 API for Configuring Raster Export
https://blogs.msdn.microsoft.com/visio/2010/03/03/new-visio-2010-api-for-configuring-raster-export/