"compressPDF"(filename, path=NULL, outFilename=basename(pathname), outPath="compressedPDFs", skip=FALSE, overwrite=FALSE, compression="gs(ebook)+qpdf", ...)TRUE and an existing output file, then it is returned.FALSE, an error is thrown if the output file
already exists, otherwise not.character vector of compression methods
to apply. This overrides any low-level arguments passed via
... that compactPDF.compactPDF,
e.g. gs_quality.compactPDF is utilized.