raster format batch conversion in R, error gdal_translate

Question

I am running a batch conversion, .grd to .tif. This code worked fine with .rst to tif but now I get the error:

/ndmi.LC81270592013272.grd' not recognized as a supported file format.

This is my code:

batch_gdal_translate(infiles=dir,outdir=output_folder,
                     outsuffix="_conv.tif",of="GTiff",pattern=".grd$", ot="Int16")

Answer 1

.grd is the header file for the native format of the raster package. As explained here, there is no gdal driver for that format, therefore you can't run gdal_translate on such files.

Two options to batch convert the files:

First option, create headers (does not duplicate the data)

Does not generate tiff files, but makes the files readable by most (all?) gis software.

library(raster)

files <- list.files('directory/with/files/to/convert', pattern = pattern = '^.*\\.grd$', full.names = TRUE)

makeHeader <- function(x){
    b <- brick(x)
    hdr(b, format = 'ENVI')
}

lapply(files, makeHeader)

Second option, read and write back to tiff (duplicates data)

files <- list.files('directory/with/files/to/convert', pattern = pattern = '^.*\\.grd$', full.names = TRUE)

convertToTiff <- function(x) {
    b <- brick(x)
    extension(x) <- '.tif'
    dt <- dataType(b)
    writeRaster(b, filename = x, datatype = dt)
}

lapply(files, convertToTiff)