Loopable Soft Noise

Generating Soft Noise on a Canvas

I'm making a space paralax game and I need a function for soft, loopable noise, to make space a little more interesting.
I've been looking at perlin-noise, but speed is an issue..

So I've been fiddling to generate this:
http://jsfiddle.net/LwDC9/1/

As you can see the texture is generated to be completely loopable at ANY format. (Perlin noise usually needs something like 2,4,8,16,32... etc)
If you want a 2048x2048 loopable texture, you'll have to wait a bit, but it'll get there. You can reduce the complexity of the rendering to optimize.

Also the texture is transparent. This is because I want to use it in a parallax.

So let's use that technique to create a huge (640x480) spaceview animation that you might know from games. (using a parallax)

http://jsfiddle.net/LwDC9/3/
Please try the fiddle, the image doesn't do justice to the animation.
I've put some text underneath the canvas, to show it's pretty transparant.
I'd like to see what the performance is on an iPad or something, but right now, I'm pretty happy with the performance in Chrome.

Now when a star dissappears it immeadeately reappears on the other side, the same goes for the colors. That kind of kills the illusion.
So I made the generated bitmaps bigger than the shown ones. I generate 4 bitmaps of 1024 by 512 and show them in a frame of 800x200.

http://jsfiddle.net/LwDC9/5/