Cloud-Optimized GeoTIFF (COG)

A Cloud-Optimized GeoTIFFGeoTIFFGeoTIFF is a public domain metadata standard that embeds georeferencing information within TIFF image files, enabling... (COG) is a regular GeoTIFF file organized so that clients can read specific regions and resolution levels via HTTP range requests, eliminating the need to download multi-gigabyte files in their entirety. This is achieved through internal tiling—splitting the image into fixed-size blocks—and embedded overviews—pre-computed reduced-resolution versions of the image. A well-formed COG also places metadata at the beginning of the file so that a single initial request reveals the file’s structure. COGs have become the de facto standard for storing and serving satellite imagerySatellite ImagerySatellite imagery consists of photographs and data captured by Earth observation satellites orbiting the planet. Thes..., aerial photography, elevation models, and other raster dataRaster DataRaster data represents geographic information as a grid of cells or pixels, where each cell holds a value representin... in cloud object stores like AWS S3, Google Cloud Storage, and AzureAzureAzure is Microsoft’s cloud computing platform that provides a comprehensive range of services, including computing, a... Blob Storage. They power platforms like the Microsoft Planetary Computer, Element 84’s Earth Search, and many SpatioTemporal Asset Catalog (STAC) endpoints. Clients such as GDALGDALGDAL (Geospatial Data Abstraction Library) is an open-source translator library for raster and vector geospatial data..., RasterioRasterioRasterio is a Python library for reading and writing geospatial raster data. Built on GDAL, it provides a Pythonic AP..., QGISQGISQGIS is a user-friendly, open-source GIS platform that provides tools for geospatial data analysis, mapping, and inte..., and web tiling services can read COGs directly from URLs without any specialized server software. Creating COGs from existing GeoTIFFs is straightforward with GDAL’s gdal_translate command using the COG driver or the ‘-co TILED=YES’ creation option combined with gdaladdo for overviews. The cogeo-mosaic and TiTiler projects enable dynamic mosaicking and visualization of COG collections. COGs dramatically reduce infrastructure costs and complexity for managing large raster archives by leveraging commodity cloud storage and standard HTTP protocols.