Adaptive linear combination of weighted medians

Kang S. Choi, Aldo W. Morales, Sung-Jea Ko

Research output: Chapter in Book/Report/Conference proceedingConference contribution


In our previous literature 1, we proposed a class of nonlinear filters whose output is given by a linear combination of weighted medians (LCWM) of the input sequence. We showed that, unlike the median type filters having the lowpass response, the LCWM filters consisting of weighted median subfilters can not only suppress both Gaussian noise and impulsive noise effectively, but also offer various frequency characteristics including lowpass, bandpass, and highpass responses. In an attempt to improve the performance of LCWM filters, we propose an adaptive LCWM (ALCWM) filter which consists of directional weighted median subfilters with different geometric structures. The weighting factor of each subfilter is adaptively determined using the similarity between the directional subwindow and the local geometric image features of interest. It is shown experimentally that the ALCWM filter performs better than the aforementioned filters including the median and the LCWM filters in preserving more details.

Original languageEnglish
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
EditorsE.R. Dougherty, J.T. Astola, K.O. Egiazarian
Number of pages9
Publication statusPublished - 2002
EventImage Processing: Algorithms and Systems - San Jose, CA, United States
Duration: 2002 Jan 212002 Jan 23


OtherImage Processing: Algorithms and Systems
CountryUnited States
CitySan Jose, CA



  • Adaptive filtering
  • Image enhancement
  • Linear combination of weighted median filter

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Condensed Matter Physics

Cite this

Choi, K. S., Morales, A. W., & Ko, S-J. (2002). Adaptive linear combination of weighted medians. In E. R. Dougherty, J. T. Astola, & K. O. Egiazarian (Eds.), Proceedings of SPIE - The International Society for Optical Engineering (Vol. 4667, pp. 484-492)