High ISO noise reduction in GIMP 2.8

I was just curious how this camera handle high ISO noise. So I made test shoots in the evening right after sunset today. The maximum ISO is 3200 for Nikon D200. Above ISO 400, RAW image develops outstanding ISO noise compared to JPEG image created in camera.

I found two street cats were mating on a back street. So I took shots changing ISO numbers. How could I just walk away! I’m an opportunistic photographer.

hDSC_0005

hDSC_0010

hDSC_0011

Nikon D200’s JPEG Medium: 2896×1944
ISO3200_jpeg_noise

RAW image after adjusting bright and default camera WB
ISO3200_raw_noise

Noise reduction applied in GIMP 2.8
I applied dechroma plug-in to above RAW image in JPEG format. It was little tricky to install the plug-in. What I did was to copy dechroma.scm to ~/.gimp-2.8/scripts directory.
-rw-r--r-- 1 penguin penguin 1.6K Apr 7 20:39 dechroma.scm
Ran [Fileters] – [Script-Fu] – [Refresh Scripts] menu
Then, [Fileters] – [jp] – [dechroma] would show up
Ran dechroma plug-in
Set [Green/Red Blur Radius] at 100 and other value in default 15.
Ran [Filters] – [Blur] – [Gaussian Blur]
Set Blur Method: RLE, Horizontal: 5.0, Vertical: 5.0
And then, removed the light cyan tone using [Colors] – [Hue-Saturation] menu.

ISO3200_raw_noise2

About janpenguin

Email: janpenguin [at] riseup [dot] net Every content on the blog is made by Free and Open Source Software in GNU/Linux.
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