IM is slow when converting last pages of big PDF to JPGs

[magick]

We need to improve the algorithm but for now it does process all pages up until your last subimage specification. We do that to be able to robustly handle specifications such as image.pdf[191,89,13] (which grabs page 191, 89, and 13 respectively). We'll look into improving this algorithm for the next point release of ImageMagick.

[magick]

We have a patch in ImageMagick 6.3.8-10 Beta to speed up converting large PDF images when only selecting a few pages (e.g. pdffile.pdf[195-199]).