how are function parameters initialized implicitly? : <p>I'm attempting to understand how are <code>image</code> and <code>imageData</code> populated. They are not declared anywhere. How does the parent function know what values to pass to these two parameters?</p>

<pre><code>var Jimp = require("jimp");
module.exports = function (context, myBlob) {
    Jimp.read(myBlob, function(err, image) {
        image.getBuffer(Jimp.MIME_TIFF, function(error, imageData) {
            context.bindings.outputBlob = imageData;
            context.done();
        });
    });
};
</code></pre>
