ImageMagick convert SVG to PNG not working with RSVG enabled

Question

I'm using ImageMagick's convert utility to convert SVG file to PNG image. At first, I used vanilla installation of IM on OSX (brew install imagemagick) to convert the SVG using:

$ convert file.svg file.png

This worked except that some of the image objects in that file were offset (actual links to images). I then read a related question that suggested ImageMagick to be compiled with rsvg support (homebrew does it with brew install imagemagick --use-rsvg).

Now, when I try to perform the conversion, no images are rendered. I tried using this SVG file, and the resulting PNG was blank. However, if any text exists on the SVG, it's rendered in the proper location. Any ideas how to proceed? thanks.

Answer 1

You should run this command to see a list of all 'delegates' your ImageMagick is trying to use:

 convert -list delegate

To discover which delegate command ImageMagick uses for SVG processing, run

 convert -list delegate | grep 'svg ='

You should see the binary + commandline parameters your convert tries to use. Im my case it is /opt/local/bin/rsvg-convert (but I'm not using Homebrew, I use MacPorts).

Now check if the binary is present at all on your system:

• If yes, run it directly and debug from there.
• If no, try to find where your Homebrew installation installed it, and change ImageMagick's configuration file for its delegates. It's called delegates.xml. MacPorts places it into /opt/local/etc/ImageMagick/delegates.xml -- I don't know where Homebrew stores it.

However, since your un-modified installation was already working, there must have been an SVG consuming delegate at work already then. Otherwise you would not have gotten any SVG processed at all.

This internal SVG rendering method of ImageMagick is called MSVG. This is far from being a feature-complete SVG interpreter/renderer.

---

Update:

To see what ImageMagick is doing for which format, run this command:

convert -list format

and for SVG run

convert -list format | grep SVG

Output on my system is:

 MSVG  SVG       rw+   ImageMagick's own SVG internal renderer
  SVG  SVG       rw+   Scalable Vector Graphics (RSVG 2.36.1)
 SVGZ  SVG       rw+   Compressed Scalable Vector Graphics (RSVG 2.36.1)

After you installed rsvg, the internal method to render SVGs will not have gone away. You can still force ImageMagick to use the internal renderer by adding MSVG: to the commandline like this:

convert  MSVG:file.svg  file.png

Just for completeness' sake...