MureDenoise and Nearest Neighbor

[alphascorpi]

Hi
I have found in the documentation of the MureDenoise script a hint to the interpolation method:
" The script provides maximum output quality when Nearest Neighbor is used".

In the documentation of the StarAlign process you can read:
" Nearest neighbor produces a useless registered image with obvious lack of subpixel accuracy and jagged stars. "

And now what is correct?
Thanks Ed

 

[dld]

Both

Nearest neighbor interpolation has the benefit of preserving the noise distribution of the original frames thus fulfilling MureDenoise requirements. But as an interpolation algorithm is not that good.

 

[mschuster]

MureDenoise works well on the interpolation options listed in its dialog parameter, but is in fact most accurate for Nearest Neighbor.

Regarding Nearest Neighbor generating useless images, it is not useless on my projects. Here is an example of two choices. Which would you choose? Left is Lanczos-4, right is Nearest Neighbor.

 

[ngc1535]

For large numbers of images, Nearest Neighbor is a super excellent way to combine images (perhaps when oversampled?). However, in testing with Lanczos resampling algorithm- the differences are small. The weird thing about nearest neighbor is that a close examination of the image (assuming not scaling or rotation) will show regions of the image that shift an integer pixel. On small scales you will not notice- but on larger scales it is kinda freaky.

-adam

 

[alphascorpi]

MureDenoise works well on the interpolation options listed in its dialog parameter, but is in fact most accurate for Nearest Neighbor.

Regarding Nearest Neighbor generating useless images, it is not useless on my projects. Here is an example of two choices. Which would you choose? Left is Lanczos-4, right is Nearest Neighbor.

MureDenoise works well on the interpolation options listed in its dialog parameter, but is in fact most accurate for Nearest Neighbor.

Regarding Nearest Neighbor generating useless images, it is not useless on my projects. Here is an example of two choices. Which would you choose? Left is Lanczos-4, right is Nearest Neighbor.

Hi Mike
Thanks for this two images. To your question: I would choose the right one
I know that MD should be used after the integration. Can you tell me if there is a preference to use MD before or after DBE?

 

[mschuster]

Can you tell me if there is a preference to use MD before or after DBE?

Before. The script won't work well if the integration has been modified.

 

[alphascorpi]

Thanks for your help.
I have learned that
1. Nearest Neighbor is a valuable choice in StarAlign if you decide to use MureDenoise
2. Mure Denoise works best with Nearest Neighbor
3. Use MureDenoise after integration and before further steps like DynamicCrop and DBE.
Ed