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HPGL Support

Sep 16, 2015 at 5:01 AM
Hi, I just ran across this today and have doing a lot of playing and am very impressed.

I have a need to be able to preview HPGL/PLT plot files. Only need to read them and I read on the ImageMagick site that it requires another plugin. The plugin is very out of date and I can't even build it since it is from V6.

Is there any way to get it to work?
Sep 16, 2015 at 11:05 AM
Edited Sep 16, 2015 at 11:42 AM
It doesn't require a plugin but an executable. This executable is called 'hp2xx.exe' and should be placed in a directory that is in your %PATH%. You could also specify the location inside the delegates.xml file., but then you would need to initialize Magick.NET with your own xml files. You can find this file in the latest portable zip of ImageMagick (The current version is:

EDIT: I should and will put this on the documentation page :)
Sep 16, 2015 at 7:59 PM
That worked great! Thank you for a quick reply with an easy solution.

I do have another one though, CGM. The link on the noted site is dead and doesn't allow a download. The needed file (whatever it is) doesn't appear to be in the package you noted. I tried all that was in it.

This product is still freaking me out, because it is as good if not better in many ways than some high dollar commercial ones out there.

If I can get this to the point of replacing a commercial product I am using, you will see a descent donation from my end.

Thanks for what you have!
Sep 16, 2015 at 8:07 PM
You can find that portable zip file here: and it does include the hp2xx.exe file.
Sep 16, 2015 at 10:05 PM
I got the hp2xx.exe file and it works great with hpgl/plt, but there is another one referenced for use with CGM. I was going to post the link it shows, but for some reason can't get to the site right now.
Sep 16, 2015 at 11:27 PM
This is the provided link, but most of the links on the site are dead, no where to get a windows version that I could find that worked...
Sep 17, 2015 at 7:24 AM
I was misunderstanding your post. I thought we were still talking about HPGL. If we can track down the source code of ralcgm we could probably include it in ImageMagick. Have you found the source code already? The only problem is that we might have a license issue. If the license is not compatible with apache2 we can not really include it.
Sep 17, 2015 at 9:03 PM
I found the source for ralgcm here: but this cannot be used due to licensing issues.

But good news! I did not check the delegates.xml file before and just assumed we needed ralcgm. But ImageMagick uses 'uniconvertor' and you can download that here: I hope this can help you replace the commercial product you are using. It is using an 'LGPL' license ( so you can use it in a commercial product.
Sep 18, 2015 at 6:29 PM
You're awesome dude! Thanks, I'll give it a shot. I've been a full time programmer now for over 30 years and I know well written code when I see it.
Sep 18, 2015 at 6:39 PM
Please let me know if you manage to get it working. I will also add this to the documentation then.
Sep 19, 2015 at 7:43 PM
I've ran some quick tests and not having any luck with CGM at this point, but it does work with DXF.
Sep 19, 2015 at 10:07 PM
It is executing the same command for both file formats:
<delegate decode="cgm" command="cmd.exe /c (&quot;uniconvertor&quot; &quot;%i&quot; &quot;%o.svg&quot;) &amp; (move &quot;%o.svg&quot; &quot;%o&quot; >nul)"/>
<delegate decode="dxf" command="cmd.exe /c (&quot;uniconvertor&quot; &quot;%i&quot; &quot;%o.svg&quot;) &amp; (move &quot;%o.svg&quot; &quot;%o&quot; >nul)"/>
It seems to use SVG as an intermediate format. Have you tried running uniconvertor on the command line and examined the resulting SVG?
Sep 20, 2015 at 5:08 PM
Edited Sep 20, 2015 at 10:56 PM
It completely fails on the command line with a not being able to load the CGM Library error, but works fine with every other file type. Can't find anything in the docs or what code I have looked at so far if any other switches are required. I have only got the GUI front end to work with Version 1 Binary files. I'm using version 1.1.5.
Sep 21, 2015 at 9:33 PM
I found an installer for 'RALCGM' here: No idea if it is legit but you could give it a try if you dare :P. You do need to modify your delegates.xml file to use RALCGM instead of uniconvertor (more details here:
Sep 22, 2015 at 12:05 AM
Thank You. I'll give it a try.
Oct 1, 2015 at 3:14 PM
Where you able to use that executable and did you get it to work?