Re: PDF with big honkin images

[Florian Kulzer <florian@molphys.leidenuniv.nl>]

Jochen Schulz wrote:
> Florian Kulzer:
>
> > Unfortunately I do not know if a "naked" CUPS has the same handy
> > pdfwriter with the option to downsample images, and I could not find
> > any command line tool to do this.
>
>
> apt-cache show cups-pdf
>
> I didn't try it, but it should downsample to printing quality and then
> make a new PDF out of it. pdf2ps and ps2pdf might also work.
>
> J.

I have now figured out how to do it with ghostscript from the command
line (after first failing with the "-r" option). The command is:

gs -q -dBATCH -dNOPAUSE -sDEVICE=pdfwrite -dDownsampleColorImages=true -dColorImageResolution=300 -sOutputFile=small.pdf big.pdf

The resolution is specified in DPI. For grayscale and monochrome images
you have to add "-dDownsampleGrayImages=true -dGrayImageResolution=..."
and "-dDownsampleMonoImages=true -dMonoImageResolution=...", respectively.

Regards,
              Florian