dataset = gdal.open(file) how can I get the compression method?

Question

I am working with various file sets and one of the things I have not been able to figure out is how to get the compression used in the file that I opened.

The challenge is that I have some different data sources and I want to be able to address the way that I handle the file based upon if the source has compressed the data (lossy) or not.

Does anyone know how to get the compression type from the gdal dataset in python?

Answer 1

Use the GDAL "IMAGE_STRUCTURE" metadata domain, i.e. dataset.GetMetadata('IMAGE_STRUCTURE')['COMPRESSION']

Example with and without compression:

from osgeo import gdal

dataset = gdal.OpenEx('int16_lzw.tif')
md = dataset.GetMetadata('IMAGE_STRUCTURE')

# Use dict.get method in case the metadata dict does not have a 'COMPRESSION' key
compression = md.get('COMPRESSION', None)

print(md)
# {'COMPRESSION': 'LZW', 'INTERLEAVE': 'BAND'}
print(compression)
# LZW

dataset = gdal.OpenEx('int16.tif') #Has no compression
md = dataset.GetMetadata('IMAGE_STRUCTURE')
compression = md.get('COMPRESSION', None)

print(md)
# {'INTERLEAVE': 'BAND'}
print(compression)
# None