title: ImageMagick batch resizing performance
body: <pre>
  convert \
     original.jpg \
    -quality 85 \
    -colorspace rgb \
    -profile /var/tmp/sRGB.icm \
    -strip \
    -profile /var/tmp/sRGB.icm \
    -filter Lanczos \
    -write mpr:17JPCONV1-original \
    +delete \
  mpr:17JPCONV1-original -crop '3000x2001+0+491' -resize '190x126!>' -write thumbWide.jpg +delete \
  mpr:17JPCONV1-original -crop '2981x2983+8+0' -resize '75x75!>' -write thumbStandard.jpg +delete \
  mpr:17JPCONV1-original -crop '3000x2983+0+0' -resize '163x163!>' -write hpSmall.jpg +delete \
  mpr:17JPCONV1-original -crop '3000x2983+0+0' -resize '1024x1019!>' -write jumbo.jpg +delete \
  mpr:17JPCONV1-original -crop '3000x2983+0+0' -resize '190x189!>' -write articleInline.jpg +delete \
  mpr:17JPCONV1-original -crop '3000x2983+0+0' -resize '2048x2037!>' -write superJumbo.jpg +delete \
  mpr:17JPCONV1-original -crop '3000x2983+0+0' -resize '592x589!>' -write tmagArticle.jpg +delete \
  mpr:17JPCONV1-original -crop '3000x2983+0+0' -resize '3000x2983!>' -write popup.jpg +delete \
  mpr:17JPCONV1-original -crop '2981x2983+8+0' -resize '640x640!>' -write square640.jpg +delete \
  mpr:17JPCONV1-original -crop '3000x1689+0+647' -resize '3000x1688!>' -write videoSmall.jpg +delete \
  mpr:17JPCONV1-original -crop '3000x2983+0+0' -resize '503x500!>' -write slide.jpg +delete \
  mpr:17JPCONV1-original -crop '2981x2983+8+0' -resize '151x151!>' -write moth.jpg +delete \
  mpr:17JPCONV1-original -crop '3000x2001+0+491' -resize '337x225!>' -write hpMedium.jpg +delete \
  mpr:17JPCONV1-original -crop '3000x2001+0+491' -resize '395x264!>' -write sfSpan.jpg +delete \
  mpr:17JPCONV1-original -crop '3000x1689+0+647' -resize '3000x1688!>' -write videoLarge.jpg +delete \
  mpr:17JPCONV1-original -crop '3000x1689+0+647' -resize '511x288!>' -write hpLarge.jpg +delete \
  mpr:17JPCONV1-original -crop '2981x2983+8+0' -resize '320x320!>' -write square320.jpg +delete \
  mpr:17JPCONV1-original -crop '3000x1689+0+647' -resize '600x338!>' -write articleLarge.jpg +delete \
  mpr:17JPCONV1-original -crop '3000x2001+0+491' -resize '3000x2000!>' -write videoThumb.jpg +delete \
  mpr:17JPCONV1-original -crop '2981x2983+8+0' -resize '150x150!>' -write thumbLarge.jpg +delete \
  mpr:17JPCONV1-original -crop '3000x2983+0+0' -resize '533x530!>' -write blog533.jpg +delete \
  mpr:17JPCONV1-original -crop '3000x2983+0+0' -resize '151x151!>' -write blogSmallInline.jpg +delete \
  mpr:17JPCONV1-original -crop '3000x2983+0+0' -resize '362x360!>' -write tmagSF.jpg +delete \
  mpr:17JPCONV1-original -crop '2981x2983+8+0' -resize '190x190!>' -write filmstrip.jpg +delete \
  mpr:17JPCONV1-original -crop '3000x2983+0+0' -resize '480x478!>' -write blog480.jpg +delete \
  mpr:17JPCONV1-original -crop '3000x2983+0+0' -resize '427x425!>' -write blog427.jpg +delete \
  mpr:17JPCONV1-original -crop '2981x2983+8+0' -resize '50x50!>' -write blogSmallThumb.jpg +delete \
  mpr:17JPCONV1-original -crop '3000x1401+0+791' -resize '151x70!>' miniMoth.jpg;
  </pre>
  
  <p>I am trying to generate ~30 crops from an original using one command (using one command is significantly faster than using a single command for each crop). However, this is taking quite a while (~30s) to finish. Any suggestions to speed this up? Can the resize command take advantage of GPUs via OpenCL?</p>
  
  <p>Update:</p>
  
  <ul>
  <li>Using -thumbnail instead of -resize improves things</li>
  <li>(Thanks to @A R for the tip) Compiling ImageMagick with libjpeg-turbo also improves times by 20%</li>
  </ul>