I'm pretty sure ImageMagick is the answer to your woes.

ImageMagick's "convert" tool can, well, convert between image formats (including SVG, PNG, and PDF), and scale, rotate, resize, etc while doing so.



I'm not on a Mac at the moment to check, but I'm also pretty sure that installation should be straightforward if you use Homebrew or MacPorts.

I do svg to ipe and ipe to pdf. I can try if you provide the svg file...

+Sajith T S it doesn't look like ImageMagick will do what I want: see https://www.imagemagick.org/Usage/formats/#vector "IM is a 'raster image processor', and while it can read or write images stored in one of the vector formats it does so by converting the image to and from a internal raster image." I need a method that will preserve the vector nature of my graphics.

+Sariel Har-Peled if you want to see how well ipe's conversion works, you could just use the SVG that I used as the figure in my LJ post. Is it possible to do an ipe conversion from the command line or do you need to fire up the GUI?

+David Eppstein Ah yes, ImageMagick uses an intermediate bitmap format. I did not realize that you are looking for true vector -> vector conversion. Sorry about the noise! And thank you for pointing that out.

I did try converting an SVG image to PDF before leaving the above comment, and the results looked good enough to me. I realize that it still will not be good enough for your uses.

Will try... Probably tomorrow....

+David Eppstein I was curious about the "uniconverter" program mentioned there (correct URL is https://sk1project.net), so I tried that. This is what came out:

https://nonzen.in/files/grid-onion.pdf
https://nonzen.in/files/grid-onion.ps

I'm not sure why it chose the black background.

Just to compare, Inkscape produced this:

https://nonzen.in/files/grid-onion-inkscape.pdf
https://nonzen.in/files/grid-onion-inkscape.ps

But Inkscape obviously has a GUI, so it is obviously disqualified...

The Inkscape version looks good, but it is not significantly smaller in file size than the Preview version.

Yes, alas. Let us just say that incumbents in the image conversion business are ripe for disruption by a command line program that produces optimized high-quality vector images! :-)

Maybe worth a try - having GhostScript clean-up the pdf generated by inkscape:
# inkscape -C -z /tmp/grid-onion.svg -A /tmp/grid-onion.pdf
# gs -q -dBATCH -dPARANOIDSAFER -dNOPAUSE -sDEVICE=pdfwrite -sOutputFile=/tmp/grid-onion2.pdf /tmp/grid-onion.pdf
# ls -ltr /tmp/grid-onion*
9688 Feb 17 07:18 /tmp/grid-onion.svg
38037 Feb 17 07:55 /tmp/grid-onion.pdf
4994 Feb 17 07:55 /tmp/grid-onion2.pdf

5k don't seem that bad, IMHO.

+Henning Rohde 5k is much better than any other method I know about, especially if it doesn't mess up the images in the process.

Inkscape has a command line option (-A) precisely to convert svg to pdf, and thus does not require a GUI.

Apparently Inkscape is even able to typeset texts using LaTeX: http://distrib-coffee.ipsl.jussieu.fr/pub/mirrors/ctan/info/svg-inkscape/InkscapePDFLaTeX.pdf

Using: "svgtoipe" and "ipetoipe -pdf" generated this:



Under linux. Size is 5K which is smaller than the svg file.

BTW, I think ipe uses the cairo library, which indeed provides a neat interface both to output to pdf and svg...

That also works:

rsvg-convert -f pdf grid-onion.svg > x.pdf

In the svgtoipe / ipetoipe -pdf output, all the line widths have been mysteriously changed from 1pt to 0.4pt.