SUM overview + cogger

README.md

1. Create input tif

gdal_translate file.tif input.tif -of GTiff -co TILED=TRUE -co COMPRESS=DEFLATE

2. Create Overview

python create_overview.py input.tif

3. Create COG

bin/cogger -output cog.tif input.tif overview.ovr.2 overview.ovr.4 overview.ovr.8

create_overview.py

import click
import numpy
import rasterio
from rasterio import transform
from rasterio.rio import options

@click.command()
@options.file_in_arg
def main(input):
    with rasterio.open(input) as src:
        profile = src.profile

        profile["blockxsize"] = 256
        profile["blockysize"] = 256
        profile["compress"] = "DEFLATE"
        profile["tiled"] = True

        arr = src.read(indexes=1)
        overview_factor = 1
        while min(src.width // overview_factor, src.height // overview_factor) > 256:
            overview_factor *= 2
            arr = arr.reshape(arr.shape[0]//2, 2, arr.shape[1]//2, 2).sum(axis=(1,-1))
            profile["width"] = arr.shape[1]
            profile["height"] = arr.shape[0]
            profile["transform"] = transform.from_bounds(*src.bounds, arr.shape[0], arr.shape[1])
            with rasterio.open(f"overview.ovr.{overview_factor}", "w", **profile) as dst:
                dst.write(arr, indexes=1)

if __name__ == '__main__':
    main()