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Webassembly ImageMagick & outputfilename in cmdline

Posted: 2018-07-13T00:19:44-07:00
by knicknic
I recompiled ImageMagick for WebAssembly, allowing it to run in your browser. You can see a sample cmdline project that uses it at
However I do not understand output filenames.

the command I was trying to run was (which you can experiment in the above sample url)

Code: Select all

convert * -flatten -crop x20% +repage -quality 100 -scene 0 -set filename:mysize %t %[filename:mysize]-%d.jpeg
I tried to split a filename of abcdefghijklmn.jpg thinking this would generate abcdefghijklmn-0.jpg, abcdefghijklmn-1.jpg, ...
However I got file name abcdefgh0.jpg. This was unexpected for 2 reasons.
  • 1. I did not abcdefghijklmn, but the shortened abcdefgh
  • My guess is that in the browser it does not detect that it is capable of longer than 8 character file names. I was wondering does anyone know where the detection for what character support your file system has is?
  • 2. I did not get '-'.
How would I get the expected abcdefghijklmn-0.jpg, abcdefghijklmn-1.jpg, ...

Lastly, any thoughts on client side ImageMagick using webassembly more info at


Re: Webassembly ImageMagick & outputfilename in cmdline

Posted: 2019-02-20T02:01:26-07:00
by knicknic
This turned out to be a bug in ImageMagick. It is currently fixed. For more info see