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Comment by mlochbaum

As you suspected, there's some older literature on this, from the 1990s in image processing. There it's not based on stacks or queues but on splitting the output into blocks with the same size as the (constant-length) window. It's sometimes called the van Herk/Gil-Werman algorithm after two sets of independent discoverers; of the two papers I prefer "Computing 2-D Min, Median, and Max Filters" by Gil and Werman which spends just a paragraph on the 1-D windowed operation in section II.

I don't know who first described this as a streaming version but I like the presentation at https://signalsmith-audio.co.uk/writing/2022/constant-time-p... . It is indeed too obscure considering how useful it is!

parent mlochbaum 16 days ago

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