How to get the extents when exporting an image from a view using C# API?

Using this post
https://forums.autodesk.com/t5/revit-api-forum/how-to-export-an-image-from-a-specific-view-using-revit-api-c/m-p/5457965
I'm able to create PNG images and store them in the local file system. The images will be created from 2D floor plans.
Now I want to know, what are the extents of the result image in local coordinates (not the count of pixel. this is an input value).
Is there a way to get that size? Or is there a way to calculate it? Or what elements will be used to create the image and is there a calculation for the border around the elements?
Thank you!
Peter