How is georeferencing data usually stored if not in the image header?

Georeferencing data is typically stored as a separate ASCII file when it is not included in the image header. This method allows for a clear distinction between the metadata needed for georeferencing and the actual image file, which can vary in format or compression. By using a separate ASCII file, users and GIS applications can easily read and edit georeference information without having to manipulate the image data itself. This also facilitates the use of the georeferencing information with different datasets or image formats.

For instance, it's common to find georeferencing information as a sidecar file, often with a similar name to the image file but with a different extension. This methodology ensures that the core image remains unaltered, while the associated geospatial information is maintained in a user-friendly and accessible text format. Additionally, this practice promotes compatibility across various GIS applications, enabling seamless integration of imagery and spatial data.

While other storage formats could theoretically be used for georeferencing data, they often introduce complexities that can hinder usability. For example, storing it in a compressed format might complicate access to the data due to unpacking needs, and storing it as a binary file could make it less readable compared to ASCII. Embedding georeferencing data directly within the image