The function calls the C GDALPolygonize routine (using C++). It does overwrite. It uses always 8 point connectedness. It writes on disc a file in "ESRI Shapefile" format.
I wrote a separate package with the function at first. However, I did not want to submit such a small package to CRAN to resolve the 'polygonize' problem. Therefor, I included the source code of that package in uFTIR at a later stage. If you are looking for a package to polygonize a raster file (similar to GDAL polygonize.py) you can use the GDALPolygonize package directly. You can find it in GitHub.
That's also why this function is not exported for you to use it.
rgdal_polygonize(raster, folder, layer, field, overwrite = TRUE)name/location of raster file to polygonize. Any driver included in GDAL should work.
name/location of the shape file to write. File extension should not be included.
name of the layer (.shp file) to write. Do not include de file extension.
name of the field that will keep the raster values.
TRUE/FALSE to overwrite an existing file (folder).
integer 0