Error: spawn ENOENT

[carlituxman]

I'm trying in node version 0.10.13 with express 3.0.4 this code

var myfile = __dirname + "/public/resources/" + "mypic.jpg"
var gm = require("gm");
gm(myfile).size(function(err, value){
console.dir(value);
});

I obtain this error:
[Inside 'uncaughtException' event] Error: spawn ENOENT
at errnoException (child_process.js:980:11)
at Process.ChildProcess._handle.onexit (child_process.js:771:34)

[jonathanong]

Do you have graphicksmagick installed?

[carlituxman]

I have installed imagemagick

[jonathanong]

did you subclass imagemagick?

[carlituxman]

perfect I've tried:
var gm = require("gm");
var imageMagick = gm.subClass({ imageMagick: true });
imageMagick(....

it works!
thanks