mapImage.imboxfilt edit page

smooth one or more images with a box filter

Cross correlation dislikes noise, so a light box filter before registration is the usual first step. This is the Image Processing Toolbox function of the same name, for mapImage and without the toolbox: the box is separable, so it is two 1-D convolutions rather than one 2-D one.

Description

Edges are handled by replicating the border, as imboxfilt does, so the filtered image does not darken towards its frame. Every channel is filtered on its own.

Non finite values are excluded rather than propagated: a NaN would otherwise spread over the whole box. Each output is the mean of the finite inputs under the box, and stays NaN only where none of them were finite. imboxfilt itself has no such behaviour - it would return NaN for the whole neighbourhood - which matters here because a resampled map is padded with NaN by construction.

Syntax

mg = imboxfilt(mg)        % 3 × 3
mg = imboxfilt(mg,5)
mg = imboxfilt(mg,[3 7])  % rows, columns

Input

mg mapImage, one or an array
k box size in pixels, odd. Scalar, or [rows cols]

Output

mg the same images, filtered

See also

mapImage mapImage.rescale mapImage.edgeMap

Citing this page. This page is part of the documentation of MTEX, a free and open source MATLAB toolbox for analyzing and modeling crystallographic textures. It was written by The MTEX Developers and is published at https://mtex-toolbox.github.io/mapImage.imboxfilt.html. If you use MTEX, or reuse text or figures from this page, in your research, please cite

F. Bachmann, R. Hielscher, H. Schaeben: Texture Analysis with MTEX - Free and Open Source Software Toolbox, Solid State Phenomena 160 (2010), 63-68. 10.4028/www.scientific.net/SSP.160.63

BibTeX 
@article{bachmann2010mtex,
  author  = {F. Bachmann and R. Hielscher and H. Schaeben},
  title   = {Texture Analysis with MTEX - Free and Open Source Software Toolbox},
  journal = {Solid State Phenomena},
  volume  = {160},
  pages   = {63-68},
  year    = {2010},
  doi     = {10.4028/www.scientific.net/SSP.160.63},
  url     = {https://doi.org/10.4028/www.scientific.net/SSP.160.63}
}

Other papers describing specific MTEX methods are listed under Publications — please cite the one that best fits your application. The MTEX source code is licensed under the GNU General Public License v2.0; the text and figures of this documentation are licensed under CC BY 4.0, which permits reuse — including by automated systems — provided The MTEX Developers and this page are credited.