Ref 2: Freeware "Ximagic Denoiser": http://www.ximagic.com/d_index.html
I downloaded the "XiDenoiser MP v 4.4.1" (32 bit) file for use with Windows Vista32 and copied it into IrfanView4.33's "Image | Effects | Adobe 8BF filters..." folder.Ximagic Denoiser is a Photoshop plugin for image noise reduction.
It provides seven different methods for noise reduction:
--Median (Std/Center Weighted)
--Gauss (Std/Bilateral)
--DWT (Overcomplete Wavelets)
--CWT (Complex wavelets)
--DCT (Discrete cosine)
--NLM (Non Local Means)
--Non-linear (anisotropic) diffusion (Curvature & Gradient)
Support of 8/16 bits images.
Support of Photoshop actions/batch.
Support use as Smart filter.
Versions for 32 and 64 bit plugin hosts.
Mac and Windows versions.
Compatible with Paint Shop Pro, The Gimp, IrfanView, XnView, ...
Then using the image examples from Ref 1, the following results were obtained after several trials where the complete settings were not recorded:
Example 1: 1 pass [NLM-std denoise]
- Example_1.jpg (39.36 KiB) Viewed 3917 times
- Example_2.jpg (47.28 KiB) Viewed 3910 times
As Irfanview4.33 is currently set for 8-bit [24 bit color] depth, the resulting noise reduced image versions are also 8-bit [24 bit color]...
...but they can be preferently blended in PWP's Composite-Blend transform where the Input is the original, noisy, 16-bit image and the Overlay is its 8-bit de-noised version... ...which with the Overlay Amount set to a preference and either Apply or OK clicked, will result in a preferentially blended 16-bit image de-noised version.
An Input image mask could also be used for specific image area and/or tone range blending control.