Morphological dilation is a sliding-window maximum nonlinear Filter over a Signal. For each sample, the output is the maximum value within a kernel of width centered on that sample:
- Applied to a Power Spectrum, dilation restores the spatial extent of broad structures that survived Morphological Erosion. Used as the second step in Morphological Opening.
- This is a Stencil operation: each output depends only on a fixed neighborhood of surrounding inputs, with a nonlinear max reduction instead of a weighted sum.