Is there a way to update metadata of an existing geotiff file? I'm particularly interested in setting the nodata value. The following does not appear to work
import rasterio
from pprint import pprint
path = '/path/to/file.tif'
with rasterio.open(path, 'r+') as src:
src.meta['nodata'] = -32767
pprint(src.meta)
The previous answers are misleading or wrong. To modify the nodata value of a GeoTIFF with Rasterio, do this
with rasterio.open(tiffname, 'r+') as dataset:
dataset.nodata = -32767
The project has tests of this usage that you may see also: https://github.com/mapbox/rasterio/blob/master/tests/test_update.py#L59-L64. Note that you may have to close and reopen the file (as done in the test) to see the nodata value take effect in your program.
The meta property of a dataset is a copy of some of its important metadata. Modifying that object has no effect on the dataset.
I don't know how to do it right with rasterio but the question includes "gdal" tag so it seems that also GDAL based answers are acceptable. In that case this GDAL tool is made for you http://www.gdal.org/gdal_edit.html.
DESCRIPTION
The gdal_edit.py script can be used to edit in place various information of an existing GDAL dataset (projection, geotransform, nodata, metadata).
The script from GDAL trunk can be found at https://trac.osgeo.org/gdal/browser/trunk/gdal/swig/python/scripts/gdal_edit.py.
