hiPassSegmentation: Contrast-Filter-Segmentation

In ggRaver/Lslide: Functions for object-oriented image analysis in landslide science

Contrast-Filter-Segmentation

Description

This function performs a contrast filter segmentation on an input RasterLayer. In the firest stept the raster is converted to a gray-scale matrix, followed by filter functions of the EBImage package. Then, the filtering is applied as mask on the segmentation-input. Afterwards, a segmentation is performed using GRASS GIS region growing. Finally, the segments are transformed to SpatialPolygonsDataFrame and returned as function output. In the future this funcion will be included in the segmentation-function.

Usage

hiPassSegmentation(input.filter, input.segmentation = input.filter,
  result.filter = NULL, scale.factor, threshold,
  env.rsaga = RSAGA::rsaga.env(), writeRaster.NAflag = -99999,
  show.output.on.console = FALSE, quiet = TRUE,
  Grass.Segmentation.Threshold = 0.24, Grass.Segmentation.Minsize = 1,
  Grass.Segmentation.Memory = 1024,
  Segments.Poly = file.path(tempdir(), "outSegPoly.shp"),
  Segments.Grid = file.path(tempdir(), "outSegGrid.sgrd"),
  load.output = FALSE, fill.holes = FALSE,
  estimateScaleParameter = FALSE, ...)

Arguments

input.filter	RasterLayer on which the filtering is applied
input.segmentation	RasterLayer for segmentation. Default: input.filter
env.rsaga	environment of SAGA GIS. Default: RSAGA::rsaga.env()
writeRaster.NAflag	NoData values for NA values in raster. Default: -99999
show.output.on.console	show output of tools on console. Default: FALSE
quiet	do not show comments and process time in console. Default: TRUE
Grass.Segmentation.Threshold	threshold used of merging segments. Default: 0.24
Grass.Segmentation.Minsize	minsize of a segment. Default: 0
Grass.Segmentation.Memory	memory used in computation. Default: 1024
Segments.Poly	output location for segmented objects (shapefile). Default: paste0(tempdir(), "/", "outSegPoly.shp")
Segments.Grid	output location for segmented grid. Default: paste0(tempdir(), "/", "outSegGrid.sgrd")
estimateScaleParameter	must be only be TRUE when scale parameter function is used. Default: FALSE
...	parameters for function hiPassThresh
Fast.Representativeness.LevelOfGeneralisation	level of generalisation for computing seed points. Default: "2.0"

Value

SpatialPolygonsDataFrame containing the segments/objects

ggRaver/Lslide documentation built on April 8, 2022, 7:14 a.m.