I humbly offer two views on the problem presented.
1) To post-process this (wonderful) picture
PictureCode's Noise Ninja proved worth to rely upon every single time I used (needed!) it.
Anyways, I did some researches for this answer; and it seems that nowadays Topaz Labs' DeNoise is the best plugin available.
There's a review of DeNoise 5 at Photographyblog and Google pointed out a comparison between these and two other plugins at Colormancer.
2) To get crispier shots in the future
From the EXIF:
- Camera: Canon EOS 60D
- F: 17mm (27mm)
- f: 4
- ISO 12800
- Exposure 30s
I strongly agree with Matt's remarks on ISO setting... just halving the ISO (and doubling the exposition!), would form a picture with much less noise.
Canon EOS 60D's sensor presents severe noise above ISO 1600 (as noted in this review).
Hence, you ought to keep ISO at 800; preferably, below that.
But, you HAVE to be told about your lens.
At 27mm a mere f/4 is, sorry, a very lousy performance... this lens worth nothing.
For hundred bucks you get at Amazon a way more faster lens, f/1.8 at 50mm.
Wonder how impossibly expensive would be f/1.4 at 50mm? Wonder not, since it's pretty affordable shall you desire it enough.
With fast lenses like these you easily can set ISO at 200 (or even 100) whilst keeping exposure times short enough for those static stars, without the need for post (lossy) processing.