I needed a way to generate low quality blurry images for use with progressively.js on this blog. The images need to be only a few 10k max. These images are just placeholders to be used until the larger one can be pulled in.

Imagemagick to the rescue! You can use the following commands to convert images into low quality ones.

# resive image.png to 800px wide and jpg format
convert image.png -resize 800 image.jpg

# blur resize and scale with low quality settings
convert -strip -interlace Plane -resize 400 -gaussian-blur 0.99 -quality 1% image.png low/image.jpg