compactPDF {tools} | R Documentation |
Re-save PDF files (especially vignettes) more compactly.
Support function for R CMD build --compact-vignettes
.
compactPDF(paths, qpdf = Sys.getenv("R_QPDF", "qpdf"), gs_cmd = Sys.getenv("R_GSCMD", ""), gs_quality = c("printer", "ebook", "screen"), gs_extras = character())
paths |
A character vector of paths to PDF files, or a length-one character vector naming a directory, when all ‘.pdf’ files in that directory will be used. |
qpdf |
Character string giving the path to the qpdf
command. |
gs_cmd |
Character string giving the path to the GhostScript executable, if that is to be used. On Windows this is the path to ‘gswin32c.exe’. |
gs_quality |
A character string indicating the quality required: the options are respectively 300, 150 and 72dpi. |
gs_extras |
An optional character vector of further options to be passed to GhostScript. |
This by default makes use of qpdf
, available from
http://qpdf.sourceforge.net/, including a Windows binary. If
gs_cmd
is non-empty, GhostScript is used.
qpdf
or gs_cmd
is run on all PDF files found, and
those which are reduced by at least 10% and 10Kb are replaced.
The main approach of qpdf
is to (losslessly) compress PDF
streams. Ghostscript does that and more (including downsampling
images) and consequently is much slower and may lose quality (but can
also produce much smaller PDF files).
An object of class c("compactPDF", "data.frame")
with a
format
and print
method. This has two columns, the old
and new sizes in bytes for the files that were changed.
The external tools used may change in future releases.
Many other (and sometimes more effective) tools to compact PDF files are available, including Adobe Acrobat (not Reader). See the ‘Writing R Extensions’ manual.