GIMP/Imagemagick Noise Removal with Median Filter
Photoshop users have had at their disposal a method of combining layers using a mathematical median function, and now the F/OSS users can use the same method to remove noise from static images!
To illustrate, here is an image of mine shot on my OM-D E-M5 at ISO 25,600:
|1/100 second, f/8, ISO 25,600|
This is a great method for reducing noise in images that are static scenes. All it requires is for the images to be properly aligned, either through a tripod, and/or using software in post.
And Imagemagick or G'MIC for GIMP.
Here are some side-by-side 100% crops to illustrate:
These results were obtained from simply median blending 10 images of the same scene. For details on how it's done, head on over and read the rest of the article:
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