Update notes for 2021-08-09

content/posts/2021-08.md

@@ -210,5 +210,20 @@ if(cells['sherpa romeo journal title'].value == cells['crossref journal title'].
   - It is faster and uses less memory than GraphicsMagick (and ImageMagick), and produces nice thumbnails from PDFs
   - One drawback is that libvips uses Poppler instead of Graphicsmagick, which apparently means that it can't work in CMYK
   - I tested one item (10568/51999) that uses CMYK and the thumbnail looked OK (closer to the original than GraphicsMagick), so I'm not sure...
+- I did some tests of the memory used and time elapsed with libvips, GraphicsMagick, and ImageMagick:
+
+```console
+$ /usr/bin/time -f %M:%e vipsthumbnail IPCC.pdf -s 600 -o '%s-vips.jpg[Q=85,optimize_coding,strip]'
+39004:0.08
+$ /usr/bin/time -f %M:%e gm convert IPCC.pdf\[0\] -quality 85 -thumbnail x600 -flatten IPCC-gm.jpg 
+40932:0.53
+$ /usr/bin/time -f %M:%e convert IPCC.pdf\[0\] -flatten -profile /usr/share/ghostscript/9.54.0/iccprofiles/default_cmyk.icc -profile /usr/share/ghostscript/9.54.0/iccprofiles/default_rgb.icc /tmp/impdfthumb2862933674765647409.pdf.jpg
+41724:0.59
+$ /usr/bin/time -f %M:%e convert -auto-orient /tmp/impdfthumb2862933674765647409.pdf.jpg -quality 85 -thumbnail 600x600 IPCC-im.jpg
+24736:0.04
+```
+
+- The ImageMagick way is the same as how DSpace does it (first creating an intermediary image, then getting a thumbnail)
+  - libvips does use less time and memory... I should do more tests!
 
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