filter_Stk: Wrapper for 'filter_Rst' to filter RasterStacks

In SchoenbergA/LEGION: artifical layer computing tool

Description

applies several filter functions to each RasterLayer in a RasterStack.

Usage

filter_Stk(stk, fLS = "all", sizes, layernames = names(stk))

Arguments

fLS	comma-separated character combinations of the desired filter functions. Select from "sum","min","max","sd","mean","modal","sobel","sobel_hrzt","sobel_vert". default = all; (see details).
sizes	numeric - a single value or combinations for the MovingWindow, number must be odd.
layernames	optional - comma-seperated character combinations of the desired layernames.
Stk	a RasterStack.

Details

available filter functions

• "sum" - sum of all cells in a MovingWindow

• "min" - minimum value of all cells in a MovingWindow

• "max" - maximum value of all cells in a MovingWindow

• "mean"- mean value of all cells in a MovingWindow

• "sd" - standard deviation of all cells in a MovingWindow

• "modal" - most frequent value of all cells in a MovingWindow

• "sobel" - sobel edge detection filter in horizontal and vertical directions

• "sobel_hrzt" - sobel edge detection filter in horizontal direction only

• "sobel_vert" - sobel edge detection filter in vertical direction only

Value

returns a RasterStack with the desired filtered artificial layers.

Author(s)

Andreas Schönberg

See Also

focal,filter_Rst

Examples

### load data
extpath <-system.file("extdata","lau_mspec.tif",package = "LEGION")
mspec <- raster::stack(extpath)
### compute all filters or every layer in stack
x <- filter_Stk(mspec,sizes=3)
x # note that the names are basic set x.1
### define layernames
ln <- c("blue","green","red","nir")
z <- filter_Stk(mspec,fLS="sum",sizes=3,layernames=ln)
names(z)
### compute specific filters
flist <- c("modal","sobel_vert","mean")
y <- filter_Stk(mspec,fLS=flist,sizes=c(3,5,7))
y

SchoenbergA/LEGION documentation built on Jan. 31, 2021, 10:12 a.m.