Median Filter — A Nonlinear Smoothing Method That Reduces Outlier Noise While Preserving Edges Relatively Well

Median Filter is a nonlinear filter that reduces noise by replacing the current pixel with the median of neighboring pixel values. It is especially effective against impulse noise such as salt-and-pepper noise, where only a small number of pixels take on abnormal values, and it generally preserves edges better than average-based filters.

11/21/2025

Nonlinear Filter — Reducing Noise with Nonlinear Operations While Preserving Image Structure

Nonlinear Filter is a filtering technique that determines the output value through nonlinear operations such as median selection, value comparison, and conditional branching, rather than through a simple average or weighted sum of input values. This makes it especially robust against impulse noise and useful for reducing noise while blurring edges less than many linear filters.

05/02/2026