Median Filter

Updated 25 Sep 2026

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What it is
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  a nonlinear local filter replacing a pixel with the median value in its neighborhood
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Example
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  the median of $10,11,12,13,255$ is $12$ , whereas the mean is $60.2$
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Use
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  particularly useful for suppressing isolated salt-and-pepper impulses
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Tradeoff
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  can preserve some edges better than smple averaging, but may remove thin features or small details
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  neighborhood sizze affects both noise removal and detail loss
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Implementation example
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  OpenCV provides medianBlur with and odd kernel size
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Related
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  Salt-and-Pepper Noise

Linked references 4