If the PDF contains encrypted blocks, this won't work, as simply zeroing out the bits will break the file. Even worse, if the PDF contains compressed chunks (wh

If the PDF contains encrypted blocks, this won't work, as simply zeroing out the bits will break the file. Even worse, if the PDF contains compressed chunks (which happens often enough), such a naive approach won't work either - the chunks would have to be uncompressed before comparison. Such a tool would need a lot of smarts to work reliably enough. At this point, I feel like a metadata stripper that understands the various watermarking methods may be easier to write.