If you have downloaded a previous version, I recommend downloading the
latest. There's an updated
user manual ~4MB and a
web version - which has seen a number of rewrites as Asterism grew.
A
searchable PDF ~20MB
EDIT: updated links
EDIT: 32 bit / HDRI on the way...
The latest version of Asterism includes a Develop function. This extends the earlier background extraction, adding auto white balance and a gamma curve, to see what you've got. The file can be saved but it's really just a look see, for now.
The Orion image is 60 minutes of data (an unfinished project) processed in Asterism and StarTools, with some final touches in ImageMagick. Noise was a problem because the image is stretched to the max to reveal detail.
Rather than apply noise reduction at post processing, it is more effective with the right tools to apply while the image is linear. Essentially, lift and suppress pixel values about the mean, rather than a median filter which reduces SNR.
EDIT: The 6yo Canon 1000D image of Antares / Rho Oph, is straight out of Develop with some touching up in IM - Laptop... The RAW files were captured at a regulated +5C - super-bias and master flat. Noise - radius 7; amount 3. Bilinear deBayer.
EDIT: Develop - background extraction, colour calibration (configurable) and stretched. It needs a little work. But not too shabby.
EDIT: Develop previews with saturation mask.