[gdal-dev] Can valid cloud-optimized geotiffs have non-sequential tile ordering?

[Scott Henderson]

Thanks for the speedy reply Even! I had not considered alternative tile layouts. I did open an issue here if others want to chime in:
https://github.com/opengeospatial/CloudOptimizedGeoTIFF/issues/37

Scott

> On 7. Jan 2025, at 17:23, Even Rouault <even.rouault at spatialys.com> wrote:
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> Scott,
> 
>> 
>> Since a key aspect of COGs is efficient network access, shouldn’t this file not be considered a COG?
> 
> The row-major order (that is tiles are sorted from top-to-bottom, left-to-right) used by the GDAL COG driver is one of the many possible ways of having spatial contiguity being omewhat reflected in a file linear organization. But someone could also possibly use other ordering techniques, like Hilbert curves or other space-filling curves (https://urldefense.com/v3/__https://en.wikipedia.org/wiki/Space-filling_curve__;!!K-Hz7m0Vt54!i4fOZAt0f-88naUsZwCsp6e1BdUfWeKREt0dNnZ0vqcPG7bqrDQ1_hFy48k2UpLR2mF9A2VgJw1Ymj-5csiACJY$ ), to also achieve that purpose. Hence COG hasn't standardized on that. You could possibly open an issue related to that at https://urldefense.com/v3/__https://github.com/opengeospatial/CloudOptimizedGeoTIFF/issues__;!!K-Hz7m0Vt54!i4fOZAt0f-88naUsZwCsp6e1BdUfWeKREt0dNnZ0vqcPG7bqrDQ1_hFy48k2UpLR2mF9A2VgJw1Ymj-5bL6VEpU$ 
> Even
> 
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