Read a gdal raster to nativeRaster — gdal_raster

Note can use scale=0,1 to convert literally any raster to image this way too.

gdal_raster_nara(
  dsn,
  target_crs = "",
  target_ext = numeric(),
  target_dim = numeric(),
  target_res = numeric(),
  bands = NULL,
  resample = "near",
  silent = FALSE,
  options = ""
)

Arguments

dsn: a raster source for GDAL
target_crs: target crs (optional)
target_ext: target extent (optional, xmin,xmax,ymin,ymax)
target_dim: target dimension (optional, ncol,nrow - one value can be 0)
target_res: target resolution (optional, resx, resy)
bands: which bands to read (we could read just the second green band, for example)
resample: optional resampling algo (near is default, use bilinear or cubic or see GDAL doc)
silent: keep quiet
options: options for the gdalwarp binary (can use c("-tr", xres, yres) in place of target_res for example)

Value

list in ximage() gdal_raster_ format as per vapour package

Examples

dsn <- "vrt:///vsicurl/http://s3.amazonaws.com/com.modestmaps.bluemarble/0-r0-c0.jpg"
dsn <- paste0(dsn, "?a_ullr=-20037508,20037508,20037508,-20037508&a_srs=EPSG:900913")
gdal_raster_nara(dsn, target_dim = c(36, 36))
#> gdalinfo - unable to open 'vrt:///vsicurl/http://s3.amazonaws.com/com.modestmaps.bluemarble/0-r0-c0.jpg?a_ullr=-20037508,20037508,20037508,-20037508&a_srs=EPSG:900913'.
#> Error in vapour_raster_info(dsn[1]): GDAL was unable to open ^^
#png <- system.file("img", "Rlogo.png", package="png")
## for dumb imagery we need to specify NO_GEOTRANSFORM or set the native affine transform
#gdal_raster_nara(sprintf("vrt://%s?a_gt =0,1,0,76,0,-1", png)) #, options = c("-to", "SRC_METHOD=NO_GEOTRANSFORM"))