Am 30.11.2015 um 22:30 schrieb Georg Baum:
1) ImageMagick has a raster image kernel, it would be a huge effort to add
vector graphics capabilities, and I doubt that this is even a goal of the
ImageMagick authors
Well, it can convert from and to PDF and EPS via Ghostscript libraries
keeping the vector information.
2) metafile2eps does not contain the conversion code. The conversion code
is in windows itself, which makes it unsuitable for ImageMagick (it is cross
platform). To understand why that is the case one needs to know a bit of the
wmf/emf file formats. They are not like most file formats, where the
contents is stored as individual objects (e.g. a green rectangle of a
certain size). Instead, the contents is stored as a transcript of windows
API calls to create the desired objects. This makes id dead easy for
developers to support wmf/emf export and display on windows: For export you
call the same routine that draws your vector graphic on screen, but with a
different so called "device context" that is associated with a EMF file. To
display a EMF file you call a windows API function to "replay" it.
However, if you want to convert the contents into your own data structures,
you basically have to replicate a lot of drawing logic from windows. The
same is true if you want to export to an EMF file without calling windows
API functions.
Interesting. Many thanks!
I am still wondering why metafile2eps required admin permissions (I
assume because it has to be installed as printer). This restriction
annoyed me and users too. I mean I spent much time to get LyX to be
installable without admin permissions and non-admin LyX users could not
benefit from Metafile2eps.
Now I got feedback that Metafile2eps makes problems on some Win 10 PCs
(I don't have Win 10 to test). Thus I had to make a decision. Since
metafile2eps is not part of LyX, I thought it is up to me what so
support via the installer. At least until now nobody commented my
third-party specific installer changes.
But to keeping the vector information is easy: Inkscape
Attached is a patch
This is indeed great news! Some years ago this was not possible. I just
tried, it works even on linux, although some more adavanced EMF features are
only available in the very latest inkscape version (which I do not have
yet).
The patch looks good to me. If this is in I am have no objections to remove
metafile2eps from the installer anymore.
OK, I put in in.
regards Uwe
