Tony Q.

But again, if you cannot provide the original Excel, I can't guess what's wrong.

If this PR doesn't break any existing feature, I can directly merge this one to master branch

#664

I'm working on XSLF namespace migration - #1538

XpdfNet looks to be a good PDF library.

According to https://github.com/nissl-lab/npoi/issues/667, I'd like to use PdfPig to extract PDF data for Toxy

Can you provide the original Excel file containing the theme?

So what is the expected result of this evaluation? I don't see you use IF statement in FormRR32.xlsx 

Can you explain why you changed GetColumns method? Is it not working?

drawing.GetShapes().Remove method definitely won't work. You can reference this post. https://stackoverflow.com/questions/54769854/how-to-remove-an-image-from-an-excel-sheet-xssf-in-java