imageQT {LS2Wstat}

Performs an image quadtree decomposition.

Description

The quadtree decomposition is achieved by recursively splitting subimages into regions of stationarity.

Usage

imageQT(image, test = TOS2D, minsize = 64,alpha=0.05, ...)

Arguments

image

An image to be decomposed.

test

A function for assessing regions of spatial homogeneity, for example
TOS2D.

minsize

The smallest region to test for homogeneity.

alpha

The significance level for the homogeneity test test.

...

Any other (optional) arguments to TOS2D.

Details

This function works by assessing an image for homogeneity. If it is not homogeneous, the image is split into its four subquadrants. Each of these is then tested for homogeneity. The heterogeneous subimages are then again subdivided and tested again. This procedure is repeated until either all subimages are deemed stationary or the minimum testing size minsize is reached.

Value

An object of class imageQT with the following components:

data.name

The image analysed.

indl

The index representation of the nonstationary images in the quadtree decomposition.

resl

The results of the stationarity testing (from binfun) during the quadtree decomposition. The results giving 0 match those contained in the indl component and the results giving 1 match those contained in the indS component.

imsize

The original image dimension.

imS

The stationary subimages in the quadtree decomposition.

indS

The index representation of the stationary images in the quadtree decomposition.

minsize

The minimum testing region used during the quadtree decomposition.

Author(s)

Sarah L. Taylor and Matt Nunes

References

Sonka, M., Boyle, R., and Hlavic, V. (1999) Image processing, analysis and machine vision. 2nd Edition, PWS Publishing.
Taylor, S.L., Eckley, I.A., and Nunes, M.A. (2014) A Test of Stationarity for Textured Images. Technometrics, 56 (3), 291-301.

See Also

plot.imageQT, TOS2D

Examples

# generate an image:
X<-simTexture(128,K=1,imtype="NS1", sd = 3)[[1]]

## Not run: XQT<-imageQT(X,binfun=TOS2D.bin)