Zakfilters
Zakfilters are a class of adaptive, nonlinear filters used to reduce noise in signals and images while preserving important features such as edges and transients. The approach combines local statistical estimation with nonlinear weighting to selectively attenuate components that differ substantially from the local signal structure.
Design and operation: The input signal is processed in overlapping neighborhoods. For each window, the filter
Extensions and variants: Multiscale and transform-domain versions exist, applying zakfiltering in wavelet or other decomposed domains
Applications: Used in digital photography, video denoising, medical imaging (such as MRI or ultrasound), and audio
Performance and considerations: Benefits include strong edge preservation and reduced ringing artifacts compared with linear filters.