MinFilter
Details
- MinFilter is a nonlinear filter commonly used to locally smooth data and diminish salt-like noise, where the amount of smoothing is dependent on the value of r.
- The function applied to each range-r neighborhood is Min .
- The data can be any of the following:
-
list arbitrary-rank numerical arraytseries temporal data such as TimeSeries , TemporalData , …audio an Audio objectvideo a Video object
- For multichannel images, MinFilter replaces each pixel by a pixel in its neighborhood that has the minimum total intensity, averaged over all channels.
- MinFilter [data,{r1,r2,…}] computes the minimum value in blocks centered on each sample.
- MinFilter assumes the index coordinate system for lists and images.
- At the data boundaries, MinFilter uses smaller neighborhoods.
Examples
open all close allBasic Examples (3)
Scope (13)
Data (8)
Parameters (5)
Specify one radius to be used in all directions:
Increasing the radius will result in darker images:
Minimum filtering just in the first direction:
Filtering just in the second direction:
Minimum filtering of a 3D image in the vertical direction only:
Filtering of a 3D image in the horizontal planes only:
Applications (3)
Use minimum filtering to remove thin, bright objects:
Remove salt noise from an image:
Use minimum filtering to locate borders in an image:
Properties & Relations (2)
For single-channel images, MinFilter is the same as ImageFilter with function Min :
For single-channel images, MinFilter is the same as Erosion with a box structuring element:
Tech Notes
History
Introduced in 2008 (7.0) | Updated in 2015 (10.2) ▪ 2016 (11.0) ▪ 2025 (14.3)
Text
Wolfram Research (2008), MinFilter, Wolfram Language function, https://reference.wolfram.com/language/ref/MinFilter.html (updated 2025).
CMS
Wolfram Language. 2008. "MinFilter." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2025. https://reference.wolfram.com/language/ref/MinFilter.html.
APA
Wolfram Language. (2008). MinFilter. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/MinFilter.html
BibTeX
@misc{reference.wolfram_2025_minfilter, author="Wolfram Research", title="{MinFilter}", year="2025", howpublished="\url{https://reference.wolfram.com/language/ref/MinFilter.html}", note=[Accessed: 05-January-2026]}
BibLaTeX
@online{reference.wolfram_2025_minfilter, organization={Wolfram Research}, title={MinFilter}, year={2025}, url={https://reference.wolfram.com/language/ref/MinFilter.html}, note=[Accessed: 05-January-2026]}