Adding datetime to each band's metadata in a multiband raster using Python

Question

I've created a multiband raster of individual rasters of temperature at different times over a period of two days using rasterio in the following way:

with rasterio.open('test.tif', 'w', **meta) as dst:
    for id, layer in enumerate(file_list, start=1):
        with rasterio.open(layer) as src1:
            dst.write_band(id, src1.read(1))

Using gdalinfo to evaluate test.tif reveals lackluster metadata for the bands.

Band 1 Block=69x3 Type=Float64, ColorInterp=Gray
Band 2 Block=69x3 Type=Float64, ColorInterp=Undefined
Band 3 Block=69x3 Type=Float64, ColorInterp=Undefined
Band 4 Block=69x3 Type=Float64, ColorInterp=Undefined

I've used this for adding a description to each band, but I have not found a way to add datetime to the metadata.

I've looked at this answer, but it only changes the description and doesn't add a new tag. Additionally, I would have to run it as a subprocess in python, and I'd prefer to do this entirely within python.

I've also looked at this answer, but using the tag TIFFTAG_DATETIME with gdal's ds.SetMetadata() is not working. It doesn't throw an error but when I view the metadata using gdalinfo or qgis nothing shows up.

Does anybody know how to add a datetime property to the metadata of a multiband raster using python?

Trying to sort out what gdalinfo or other metadata viewers will pull for GeoTIFFs can be a world of pain. For a "data cube" such as yours are you able to write data out to a netCDF file? That format will have far richer metadata support baked in. — Charlie Parr, May 07 '21 at 19:58
I could look into that if you think that's easier to edit the metadata! — JWB, May 07 '21 at 20:00
In my opinion it is easier - you'll have to judge for yourself as to if it suits your purposes but here is a link to get started reading GeoTIFFs: http://xarray.pydata.org/en/stable/user-guide/io.html — Charlie Parr, May 07 '21 at 20:04

user2856 · Accepted Answer · 2021-05-09T04:24:29.627

You can use ds.update_tags(band, tag=value). See the docs for additional info.

Here's an example with an existing dataset (opened in r+ mode).

import rasterio as rio
with rio.open('test.tif', 'r+') as ds:
    for i in range(1, ds.count+1):
        # Here I add a non-standard tag called "DATE_TIME"
        # this can be anything, like "MY_CUSTOM_BAND_DATE_TIME_TAG"
        # Or you could use "TIFFTAG_DATETIME" if you want. Up to you...
        ds.update_tags(i, DATE_TIME='2021-05-08T14:30')

Your code would look something like:

with rasterio.open('test.tif', 'w', **meta) as dst:
    for id, layer in enumerate(file_list, start=1):
        with rasterio.open(layer) as src1:
            dst.write_band(id, src1.read(1))
            dst.update_tags(id, DATE_TIME='2021-05-08T14:30')

Adding datetime to each band's metadata in a multiband raster using Python

1 Answers1