I have bene using node-imagemagick for a few days now and have come to realize that it has bugs.
There are about 100 forks of it, some of which fix some of the issues i have come across, but it is hard to figure out which fork i should use.
I chose to use gm node module on one of my project. It works pretty well.
See : http://aheckmann.github.com/gm/
It's basically a wrapper around imageMagick or graphicsmagick binaries.
Here is a simple example :
var gm = require('gm');
gm('/path/to/image.jpg')
.resize(353, 257)
.autoOrient()
.write(writeStream, function (err) {
if (!err) console.log(' hooray! ');
});