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Old 03-07-2016, 07:42 PM
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Shiraz (Ray)
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Join Date: Apr 2010
Location: ardrossan south australia
Posts: 4,918
Iris is great. http://www.astrosurf.com/buil/us/iris/iris.htm

1. load an image.
2. manually select a small region in an image where there is no structure and no obvious hot pixels, right click on it and select "statistics" - "mean" gives you signal and "sigma" the noise power. The main idea is to get a large enough region that the SD is meaningful, but you need to ensure that you don't include abnormal outliers (hot/warm pixels etc) that could distort the result.

Last edited by Shiraz; 07-07-2016 at 11:41 AM.
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