I have been reading up on noise reduction for astrophotos. A lot of my moon images had specks/grain on the image which was caused by noise from the camera/s being used to take the photos themselves. After a little bit of research, I came across some free software called "Noiseware", made by Imagenomic. It basically takes an existing image and very simply removes any noise from the image using a noise filtering algorithm while also trying to maintain the image sharpness. I've tried doing this in Adobe Photoshop with so-so results, but this little tool is quite good.
In the example below, I used an image of the Lunar Alps that I took a few months ago. The image to the top is the image that was run through Adobe Photoshop with a bit of sharpening, adjust curves and noise modification. The image to the bottom is the same image run through Noiseware. Very nice improvement, with a very natural look to it.
If you up for trying it, you can download it here.
I ran another semi-moon image through the Noiseware tool and itr also produced a nice result overall. The image to the left is the original, the image to the right is the Noiseware version. Click on each to see the difference!