Quote:
Originally Posted by irwjager
That is really, really cool Steven!
This made me wonder about two other techniques that could be used to bring out that hidden beast. They are probably somewhat less scientific and hinge on some assumptions, but I'd love to hear what you think.
A galaxy is far away. We can therefore assume that most, if not all, stars belonging to that galaxy are small. Because we know the population of small stars in the image is skewed in certain places in the image because of the presence of the hidden galaxy, we can bring out the galaxy by emphasizing small stars.
The latter can be accomplished by simply generating a star mask that only contains small stars. Having isolated only the small stars we can then manipulate them in any way we wish.
Trick #2 is 're-synthesising' (if you will) a super structure from the density distribution of the small stars. For this I used a trick I sometimes like to use to 'liven up' nebulas somewhat. I layer the image with a blurred copy of itself in screen mode and apply a luminance mask so the screening is only applied to the darker parts of the image. The Gaussian blur in this instance spreads the energy of each star over a larger area, creating a large scale super structure which is easier to see.
Higher res image at http://www.startools.org/download/potw1126a_ST.png |
Well done Ivo.
I checked a region of the background in your higher resolution image and found Sky Brightness is 25.7 ADU and noise is 1.6 ADU.
The important point is you haven't accentuated the noise or the background.
I think you should seriously consider sending the image to ESO.
I checked their copyright conditions and manipulating their images is OK.
Regards
Steven