The problem with ImageMagick is that its scripting language sucks. I had tried using it a couple of times but it's too obscure and sparsely documented to get it

The problem with ImageMagick is that its scripting language sucks. I had tried using it a couple of times but it's too obscure and sparsely documented to get it to work for you. In the end I gave up because I realized that the result would be unmaintainable, so I'm better off with bash scripts. Sips got it right with providing a Javascript API instead of inventing another obscure DSL.