GPU 5×5 median that replaces a pixel only when it differs from the neighborhood median by at least the threshold.
Median GPU runs a component-wise 5×5 median on the GPU with Blink, edge-clamped over a ±2 sample range, then compares that result to the source.
A MergeExpression measures per-channel absolute difference against the threshold. Where any channel meets or exceeds the threshold, the median value is written; otherwise the original pixel is kept. Alpha outputs the mask of pixels that were replaced.
Use it when you need a light, selective median pass—spike or salt-and-pepper cleanup—without filtering every pixel. Raise or lower threshold to control how large a deviation must be before the median wins.