DRIP (version 1.9)

stepEdgeParSelLL2K: edge detection, parameter selection

Description

Select threshold value for LL2K edge detector using bootstrap procedure

Usage

stepEdgeParSelLL2K(image, bandwidth, thresh, nboot)

Value

Returns a list of the selected bandwdith, the selected threshold value, and a matrix of \(d_{KQ}\) values with each entry corresponding to each combination of bandwdith and threshold.

Arguments

image

A square matrix object of size n by n, no missing value allowed.

bandwidth

Positive integers to specify the number of pixels used in the local smoothing. These are the bandwidth parameters to be chosen from.

thresh

Threshold values to be chosen from.

nboot

Number of bootstrap samples.

Details

A jump-preserving local linear kernel smoothing is applied to estimate the discontinuous regression surface; Bootstrap samples are obtained by drawing with replacement from the residuals and the \(d_{KQ}\) is computed for the detected edges of the original sample and those of the bootstrap samples.

References

Kang, Y., and Qiu, P., "Jump Detection in Blurred Regression Surfaces," Technometrics, 56, 2014, 539-550.

See Also

stepEdgeParSelLCK, stepEdgeParSelLLK, stepEdgeParSelLC2K, stepEdgeLL2K

Examples

data(sar) # SAR image is bundled with the package and it is a
          # standard test image in statistics literature.
set.seed(24)
parSel <- stepEdgeParSelLL2K(image = sar, bandwidth = 5, thresh = 20:21, nboot = 1) # Time consuming