stacking images in median mode

[tomczak]

Here is an article about stacking several images to eliminate the moving elements in the picture

https://luminous-landscape.com/making-p ... s-go-away/

What interests me is the simple technique: taking the median of each pixel across all aligned images, to do it.

I can't figure out a way to simulate something similar in PWP...

[ksinkel]

Jon has added Median as a new method to Stack Images in the next update of PWP. In addition, Stack images will accept up to 16 images to allow averaging over a larger number of exposures.

Kiril

[Dieter Mayr]

Kiril, Jonathan,

Median does work the same as it's name equivalent in mathematics/statistics ?
Adding up all values and dividing by the number of values ?
I had a quick search how it works in Photoshop in the LL example Marciej posted, but didn't find a good explanation so far.

Thanks!

[jsachs]

That is the mean -- the median is the number such that half the values are above and half below it. In this case if most of the images don't contain an object it will not appear in the result image.

[Dieter Mayr]

Ah, now I understand! Mathematical terms in english, not my strongpoint ...
Thank you, Jonathan!

[tomczak]

That's great news!

I may be pushing it, but one common problem with stacking images is aligning them first - tripod helps... One way of trying to do that is using Composite with multipoint warping, but I wasn't v. successful with it - perhaps I didn't try hard enough.

Could someone that tried some alignment techniques comment on what worked, what didn't?

Cheers!

[jsachs]

Removing lens distortion and light falloff first helps. Then you should only need 2 point (shift, rotate) alignment at most.