[cups] Trying to work around Canon MF743cdw driver bugs on MacOS Catalina

[Brian Demsky]

I recently bought a Canon MF743cdw printer, and their drivers have issues with printing a bunch of pdfs either via Preview or lpr.  It prints empty boxes instead of characters from several fonts.  The fonts are all embedded into the PDF, so it should not be a system font issue.

If I grab the input file to the canon cupsFilter (from the spool directory), it renders fine on Preview or Adobe Acrobat.  So it seems that it is a Canon issue.  

The pdf file prints okay on Acrobat and also prints okay if I use Preview to convert them to TIFF files and then print those.

Getting Canon to do anything about their driver bug appears very difficult and their tech support just blames the bug on Apple.

So I’m wondering if there is a way to hack the PPD file to render the PDF into a bitmap file, then back to a PDF, and then through the Canon driver filter.  Or some other conversion that will change the PDF files enough that the printer driver can print it.

Thanks,
Brian