preProcess_gaussFilter {cmcR}

Performs a low, high, or bandpass Gaussian filter on a surface matrix with a particular cut-off wavelength.

Description

Performs a low, high, or bandpass Gaussian filter on a surface matrix with a particular cut-off wavelength.

Usage

preProcess_gaussFilter(x3p, wavelength = c(16, 500), filtertype = "bp")

Arguments

x3p

an x3p object containing a surface matrix

wavelength

cut-off wavelength

filtertype

specifies whether a low pass, "lp", high pass, "hp", or bandpass, "bp" filter is to be used. Note that setting filterype = "bp" means that wavelength should be a vector of two numbers. In this case, the max of these two number will be used for the high pass filter and the min for the low pass filter.

Value

An x3p object containing the Gaussian-filtered surface matrix.

See Also

https://www.mathworks.com/matlabcentral/fileexchange/61003-filt2-2d-geospatial-data-filter?focused=7181587&tab=example

Examples

data(fadul1.1_processed)

#Applying the function to fadul1.1_processed (note that this scan has already
#  been Gaussian filtered)
cmcR::preProcess_gaussFilter(fadul1.1_processed)

#As a part of the recommended preprocessing pipeline (take > 5 sec to run):
## Not run: 
nbtrd_link <- "https://tsapps.nist.gov/NRBTD/Studies/CartridgeMeasurement/"
fadul1.1_link <- "DownloadMeasurement/2d9cc51f-6f66-40a0-973a-a9292dbee36d"

fadul1.1 <- x3ptools::read_x3p(paste0(nbtrd_link,fadul1.1_link))
fadul1.1_extCropped <- preProcess_crop(x3p = fadul1.1,
                                       region = "exterior",
                                       radiusOffset = -30)

fadul1.1_intCroped <- preProcess_crop(x3p = fadul1.1_extCropped,
                                      region = "interior",
                                      radiusOffset = 200)

fadul1.1_leveled <- preProcess_removeTrend(x3p = fadul1.1_intCroped,
                                           statistic = "quantile",
                                           tau = .5,
                                           method = "fn")
fadul1.1_filtered <- preProcess_gaussFilter(x3p = fadul1.1_leveled,
                                            wavelength = c(16,500),
                                            filtertype = "bp")

x3pListPlot(list("Original" = fadul1.1,
                 "Ext. & Int. Cropped" = fadul1.1_intCroped,
                 "Cropped and Leveled" = fadul1.1_leveled,
                 "Filtered" = fadul1.1_filtered),type = "list")

## End(Not run)