Question: Quartz filters can't filter certain pdfs...
I have an automator set up to convert pdfs to grayscale. It can convert some pdfs, but it converts some pages, and not others, of other pdfs. It doesn't seem to depend on image format: some non-jpeg-2000 images resist conversion, some jpeg-2000 images get converted into other formats.
Any idea what is going on?
MacBook Air (11-inch Mid 2013), macOS Sierra (10.12.6)