I made ​​a build of the poppler-utils-0.15 on Windows. I needed a newer version of pdftops, the one from the xpdf binaries which to old ...

The build works on my machine, I hope it does on others as well. Feel free to try it.

Not everyone has an Adobe Acrobat Professional license, much less one has necessarily an operating system running on the Acrobat. That's why I've been looking for a way to optimize PDFs with Open Source software, so to reduce the file size by compression and resampling images.
And I also found it. With the combination xpdf and ghostscript can be accomplished that.

I have assembled a small script for Windows where you have to adjust only the paths:

set xpdf="X:\Path\to\xpdf"
set ghostscript="X:\Path\to\ghostscript\bin"
set suffix="_opt.pdf"
%xpdf%\pdftops.exe -paper match -level3 hsq.pdf tmp.ps
%ghostscript%\gswin32c.exe -sDEVICE=pdfwrite -dPDFSETTINGS=/ebook -dColorConversionStrategy=/LeaveColorUnchanged -dBATCH -dNOPAUSE -sOutputFile=hsq.pdf%suffix% tmp.ps
del tmp.ps


The entire course is under Linux / Mac if installed xpdf and ghostscript:

suffix="_opt.pdf"
pdftops -paper match -level3 hsq.pdf tmp.ps
gs -sDEVICE=pdfwrite -dPDFSETTINGS=/ebook -dColorConversionStrategy=/LeaveColorUnchanged -dBATCH -dNOPAUSE -sOutputFile=hsq.pdf$suffix tmp.ps
rm tmp.ps

The more recent are the respective versions the better the result looks like. At least my experience.