[magick-users] CMYK PDF read as CMY (without K channel).

[duc.sequere.aut.de.via.decede at imagemagick.org]

> convert -colorspace CMYK original_cmyk.pdf result_cmyk.jpg

Try

  convert original_cmyk.pdf -colorspace CMYK result_cmyk.jpg
  identify -verbose result_cmyk.jpg

Does the black channel show a standard-deviation other than 0?  If so, try
this command with a release release of ImageMagick and see if it makes a
difference.