Read CRS metadata from a GeoTIFF

Returns the spatial reference system embedded in a GeoTIFF, parsed from the GeoKey directory (TIFF tag 34735). The projected CRS EPSG (PCSTypeGeoKey 3072) is preferred over the geographic CRS EPSG (GeographicTypeGeoKey 2048). Citation strings are read from GeoAsciiParams (tag 34737) with priority PCS > GeoTIFF > geographic.

Usage

tiff_crs(path)

Arguments

path

Path to a GeoTIFF file.

Value

A list with elements epsg (integer or NA_integer_) and citation (character or NA_character_).

Details

Files written without a GeoKey directory return NA for both fields.

Examples

# \donttest{
f <- tempfile(fileext = ".tif")
df <- data.frame(x = 1:4, y = rep(1:2, each = 2), band1 = as.double(1:4))
write_tiff(df, f)
tiff_crs(f)  # epsg = NA, citation = NA — vectra writer omits GeoKeys
unlink(f)
# }