There is a bug in Inkscape where JPEG images included in an SVG document are embedded as bitmaps rather than JPEG when exporting to PDF files.
The result is a huge increase in file size. For example, I have a simple SVG drawing which includes a 2 MB JPEG image; exporting to PDF results in a 14 MB file.
I am looking for a workaround. Is there a way to fix the resulting PDF by inserting the correctly-encoded JPG image, perhaps via some sort of pdftk trickery?
(In my case, the resulting PDF will be included as a figure in a LaTeX document rendered with pdflatex, so there may be workarounds other than directly fixing the PDF generated by Inkscape.)
One kludge is to use pdf2ps followed by ps2pdf, which will re-encode the bitmap data as JPEG:
pdf2ps made-by-inkscape.pdf foo.ps
ps2pdf foo.ps smaller-file.pdf
For my test case, the file sizes were:
original JPEG 2.1M
made-by-inkscape.pdf 15M
foo.ps 104M
smaller-file.pdf 1.5M
But of course, this involves re-encoding the JPEG data, which is best avoided.