Multiple exposures 18 in total for long exposure effect

Started 10 months ago | Discussions thread
JimKasson
JimKasson Forum Pro • Posts: 29,578
Re: Median vs average

JimKasson wrote:

Greg7579 wrote:

I am probably embarrassing myself here, but how does this remove the crowds?

Consider one pixel of a four images. One has part of a person in it. The other three does not. Say the part of the person is pure, bright red (255,0,0). Say the same place where the person is not is middle grey (127, 127,127). The median of the four frames is (127,127, 127). It's as if the person were never there.

In camera systems use averaging, because median processing is too computationally expensive. The average value for the above pixel is (159, 127,127). A red ghost of the person remains.

I did the math wrong in the last paragraph. The average value is (159,95,95).

Sorry.

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