mosaic_rasters: Mosaic raster files using GDAL Utilities

Description

Mosaic raster files using GDAL Utilities

Usage

mosaic_rasters(
  gdalfile,
  dst_dataset,
  output.vrt = NULL,
  output_Raster = FALSE,
  separate = FALSE,
  trim_margins = NULL,
  gdalwarp_index = 1,
  gdalwarp_params = list(r = "near"),
  force_ot = NULL,
  verbose = FALSE,
  ...
)

Arguments

gdalfile

Character. Input files (as a character vector) or a wildcard search term (e.g. "*.tif")

dst_dataset

Character. The destination file name.

output.vrt

Character. Output VRT file. If NULL a temporary .vrt file will be created.

output_Raster

Logical. Return output dst_dataset as a RasterBrick?

separate

Logical. (starting with GDAL 1.7.0) Place each input file into a separate stacked band. Unlike gdalbuildvrt, the full stack is placed in the mosaic, not just the first band.

trim_margins

Numeric. Pre-crop the input tiles by a fixed number of pixels before mosaicking. Can be a single value or four values representing the left, top, right, and bottom margins, respectively.

gdalwarp_index

Numeric. If gdalwarp_index is numeric, the value is used as the index of the gdalfile to match projections and resolutions against when file projections don't match. The default = 1 (the first input file).

gdalwarp_params

List. Set gdalwarp parameters if input file projections don't match. t_srs and tr set here will override those chosen by gdalwarp_index. In general, the only thing you would set here is the resampling algorithm, which defaults to nearest neighbor ("near").

force_ot

Character. ("Byte"/"Int16"/"UInt16"/"UInt32"/"Int32"/"Float32"/"Float64"/"CInt16"/"CInt32"/"CFloat32"/"CFloat64") Forces all bands to be the same datatype. This is helpful if you are using input files of different data types and output formats (e.g. GTiff) that don't support mixed datatypes.

verbose

Logical. Enable verbose execution? Default is FALSE.

...

Parameters to pass to gdalbuildvrt or gdal_translate.

Value

Either a list of NULLs or a list of RasterBricks depending on whether output_Raster is set to TRUE.

Details

This function mosaics a set of input rasters (gdalfile) using parameters found in gdalbuildvrt and subsequently exports the mosaic to an output file (dst_dataset) using parameters found in gdal_translate. The user can choose to preserve the intermediate output.vrt file, but in general this is not needed.

Examples

Run this code

# NOT RUN {
# We'll pre-check to make sure there is a valid GDAL install
# and that raster and rgdal are also installed.
# Note this isn't strictly neccessary, as executing the function will
# force a search for a valid GDAL install.
outdir <- tempdir()
gdal_setInstallation()
valid_install <- !is.null(getOption("gdalUtils_gdalPath"))
if(require(raster) && require(rgdal) && valid_install)
{
layer1 <- system.file("external/tahoe_lidar_bareearth.tif", package="gdalUtils")
layer2 <- system.file("external/tahoe_lidar_highesthit.tif", package="gdalUtils")
mosaic_rasters(gdalfile=c(layer1,layer2),dst_dataset=file.path(outdir,"test_mosaic.envi"),
		separate=TRUE,of="ENVI",verbose=TRUE)
gdalinfo("test_mosaic.envi")
}
# }