Didge Posted September 26, 2022 Share Posted September 26, 2022 Hi, I've been experimenting with different stacking methods, and (finally) understand the algorithms behind Mean, Median and Sigma stacking. My question relates to how the Mean / Median / SD is calculated for an RGB pixel stack. Am I correct that, for each pixel stack :- a. find the mean / median / Sigma for each of the R, G, B values separately, for each pixel stack; then b. combine those RGB values to create a mean / median / SD RGB pixel ? In other words, are the R, G and B values each processed separately, or is some other metric (eg the L in an HSL model) used to determine the mean / median / Sigma ? I hope that makes sense Gary Quote Link to comment Share on other sites More sharing options...
Lisbon Posted September 26, 2022 Share Posted September 26, 2022 Hi Gary. 11 hours ago, Gary.JONES said: In other words, are the R, G and B values each processed separately Yes. You can check this by generating 3 layers and filling them with some random RGB values. Stack the layers, set the stack to Mean, Median or SD and check the values in the info panel. Finally, do the math in a spreadsheet to compare the values with the info panel. Here is an example: NotMyFault and Leigh 1 1 Quote Link to comment Share on other sites More sharing options...
Didge Posted September 26, 2022 Author Share Posted September 26, 2022 Hi Lisbon, Many thanks for your speedy reply - it was very helpful. It all makes sense now Regards, Gary Lisbon 1 Quote Link to comment Share on other sites More sharing options...
Lisbon Posted September 27, 2022 Share Posted September 27, 2022 You're welcome Gary. Quote Link to comment Share on other sites More sharing options...
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