gdalUtil: Interface to GDAL Python-based utilities

In sen2r: Find, Download and Process Sentinel-2 Data

Interface to GDAL Python-based utilities

Description

This accessory function interfaces with GDAL utilities (sen2r must be interfaced with a runtime GDAL environment, see check_gdal()). Python-based utilities are always called from a runtime GDAL; C-based ones are called using sf::gdal_utils().

Usage

gdalUtil(
  util = "info",
  source,
  destination = character(0),
  options = character(0),
  quiet = FALSE,
  formula = character(0),
  processing = character(0),
  colorfilename = character(0)
)

Arguments

util	Character: one among "info", "translate", "warp", "demprocessing" ,"buildvrt" (C-based), "calc" and "fillnodata" (Python-based). Other utilities were not implemented, since they are not used by sen2r.
source	path of input layer(s); for calc this can be more than one.
destination	Path of the output layer.
options	Character vector with GDAL options.
quiet	Logical: if TRUE, suppress printing of output for info (this argument is ignored in case package sys is not installed).
formula	(for util = "calc") Calculation in gdalnumeric syntax using +, -, /, *, or any numpy array functions (i.e. log10()).
processing	Character: processing options for util = "demprocessing".
colorfilename	Character: name of colour file for util = "demprocessing" (mandatory if processing="color-relief").

Value

A logical (invisible) indicating success (i.e., TRUE); in case of failure, an error is raised and FALSE is returned (in case of Python-based utilities).

Note

License: GPL 3.0

Author(s)

Luigi Ranghetti, phD (2020)

References

L. Ranghetti, M. Boschetti, F. Nutini, L. Busetto (2020). "sen2r": An R toolbox for automatically downloading and preprocessing Sentinel-2 satellite data. Computers & Geosciences, 139, 104473. \Sexpr[results=rd]{tools:::Rd_expr_doi("10.1016/j.cageo.2020.104473")}, URL: https://sen2r.ranghetti.info/.

Examples

# Define product names
examplename <- system.file(
  "extdata/out/S2A2A_20190723_022_Barbellino_BOA_10.tif",
  package = "sen2r"
)


## gdalinfo
out0 <- gdalUtil("info", examplename, quiet = TRUE)
message(out0)

## gdal_translate
outname1 <- tempfile(fileext = ".tif")
gdalUtil(
  "translate", 
  examplename, outname1,
  options = c("-tr", "2", "2", "-r", "cubicspline", "-co", "COMPRESS=DEFLATE")
)
oldpar <- par(mfrow = c(1,2), mar = rep(0,4))
image(stars::read_stars(examplename), rgb = c(11,8,4), useRaster = TRUE)
image(stars::read_stars(outname1), rgb = c(11,8,4), useRaster = TRUE)

## gdalwarp
outname2 <- tempfile(fileext = ".tif")
gdalUtil(
  "warp", 
  examplename, outname2,
  options = c("-t_srs", "EPSG:32633", "-co", "COMPRESS=DEFLATE")
)
oldpar <- par(mfrow = c(1,2), mar = rep(0,4))
image(stars::read_stars(examplename), rgb = c(11,8,4), useRaster = TRUE)
image(stars::read_stars(outname2), rgb = c(11,8,4), useRaster = TRUE)


## Not run: 
## gdal_calc
outname3 <- tempfile(fileext = ".tif")
ndvirefname <- system.file(
  "extdata/out/S2A2A_20190723_022_Barbellino_NDVI_10.tif",
  package = "sen2r"
)
gdalUtil(
  "calc", 
  rep(examplename,2), outname3,
  formula = "10000*(A.astype(float)-B)/(A+B)",
  options = c("--A_band", "8", "--B_band", "4", "--type", "Int16")
)
oldpar <- par(mfrow = c(1,2), mar = rep(0,4))
image(stars::read_stars(ndvirefname), useRaster = TRUE)
image(stars::read_stars(outname3), useRaster = TRUE)

## End(Not run)

sen2r documentation built on Nov. 10, 2023, 9:08 a.m.