An Introduction to Cloud Optimized GeoTIFFS (COGs) Part 3: Dynamic Web Tiling with Titiler


Here we are going to take a set of COGs we generated from the Introduction to COGs tutorial and place them on Google Cloud to be publicly ingestible. First, we will demonstrate how to upload sample COGs to a bucket in Google Cloud Storage and make them publicly readable. We can then stream the COG from its online location and read into QGIS Desktop or the cogeo.com/map tool.

Uploading COGs to Google Cloud Storage

Creating a Bucket

A bucket serves as a container to store your data. In our case, this is where we will store our collection of COGs. For the purpose of this demonstration, when creating the bucket we did not enforce public access prevention because we want our COGs accessible to the internet. We also set access control to be Uniform Bucket Access. Please select the best options for your use case.

Making Objects Within Bucket Publicly Readable

Now we want to make our sample COGs readable to the public internet. To do so, we need go to Permissions, add allUsers as a new member, and set the role to be Storage Object Viewer

To learn more about bucket creation and access control specifications that best suits your particular use case, refer to https://cloud.google.com/storage/docs/how-to to learn more about working with Google Cloud Storage.


Streaming Our COGs

Now that we have stored our COGs online in a newly created storage bucket, we can now start streaming these COGs from their online locations and take a look!

Using cogeo.com/map

cogeo.com has a great mapping tool that you can use to display any COG that is stored online. This tool basically turns COGs into web tiles through the underlying web tiling service called tiles.rdnt.io. By entering the public url into the search bar, you can inspect your COG, zoom around, and share it with others.