gdalwarp: Interface to GDAL's gdalwarp utility

In gdalUtilities: Wrappers for 'GDAL' Utilities Executables

Interface to GDAL's gdalwarp utility

Description

This function provides an interface mirroring that of the GDAL command-line app gdalwarp. For a description of the utility and the arguments that it takes, see the documentation at https://gdal.org/programs/gdalwarp.html.

Usage

gdalwarp(
  srcfile,
  dstfile,
  ...,
  s_srs,
  t_srs,
  ct,
  to,
  vshift,
  novshift,
  s_coord_epoch,
  t_coord_epoch,
  order,
  tps,
  rpc,
  geoloc,
  et,
  refine_gcps,
  te,
  te_srs,
  tr,
  tap,
  ts,
  ovr,
  wo,
  ot,
  wt,
  r,
  srcnodata,
  dstnodata,
  srcalpha,
  nosrcalpha,
  dstalpha,
  wm,
  multi,
  q,
  IF,
  of,
  co,
  cutline,
  cl,
  cwhere,
  csql,
  cblend,
  crop_to_cutline,
  overwrite,
  nomd,
  cvmd,
  setci,
  oo,
  doo,
  config_options = character(0),
  dryrun = FALSE
)

Arguments

srcfile	Character. Path to a GDAL-supported readable datasource.
dstfile	Character. Path to a GDAL-supported output file.
...	Here, a placeholder argument that forces users to supply exact names of all subsequent formal arguments.
s_srs, t_srs, ct, to, vshift, novshift	See the GDAL project's gdalwarp documentation for details.
s_coord_epoch, t_coord_epoch, order, tps, rpc, geoloc, et	See the GDAL project's gdalwarp documentation for details.
refine_gcps, te, te_srs, tr, tap, ts, ovr, wo, ot, wt, r, srcnodata	See the GDAL project's gdalwarp documentation for details.
dstnodata, srcalpha, nosrcalpha, dstalpha, wm, multi, q, IF, of, co	See the GDAL project's gdalwarp documentation for details.
cutline, cl, cwhere, csql, cblend, crop_to_cutline, overwrite	See the GDAL project's gdalwarp documentation for details.
nomd, cvmd, setci, oo, doo	See the GDAL project's gdalwarp documentation for details.
config_options	A named character vector with GDAL config options, of the form c(option1=value1, option2=value2). (See here for a complete list of supported config options.)
dryrun	Logical (default FALSE). If TRUE, instead of executing the requested call to GDAL, the function will print the command-line call that would produce the equivalent output.

Value

Silently returns path to dstfile.

Author(s)

Joshua O'Brien

Examples

## Prepare file paths
td <- tempdir()
in_tif <- file.path(td, "tahoe.tif")
gcp_tif <- file.path(td, "tahoe_gcp.tif")
out_tif <- file.path(td, "tahoe_warped.tif")

## Set up some ground control points, then warp
file.copy(system.file("extdata/tahoe.tif", package = "gdalUtilities"),
          in_tif)
## Four numbers: column, row, x-coord, y-coord
gcp <- matrix(c(100, 300, -119.93226, 39.28977,  ## A
                0,   300, -119.93281, 39.28977,  ## B
                100, 400, -119.93226, 39.28922,  ## C
                0,   400, -119.93281, 39.28922,  ## lower-left
                400,   0, -119.93067, 39.29136,  ## upper-right
                400, 400, -119.93062, 39.28922,  ## lower-right
                0,     0, -119.93281, 39.29141), ## upper-left
              ncol = 4, byrow = TRUE)

## Add ground control points. (For some reason, this drops CRS, so
## it needs to be explicitly given via `a_srs` argument.)
gdal_translate(in_tif, gcp_tif, gcp = gcp, a_srs = "EPSG:4326")
gdalwarp(gcp_tif, out_tif, r = "bilinear")

## Check that it worked
if(require(terra)) {
    op <- par(mfcol = c(1, 2))
    r1 <- plot(rast(in_tif), main = "Original raster")
    r2 <- plot(rast(out_tif), main = "Warped raster")
    par(op) ## Reset preexisting parameters
}

gdalUtilities documentation built on Aug. 10, 2023, 5:08 p.m.