4 ms·
> [Geohash] subdivides space into buckets of grid shape, which is one of the many applications of what is known as a [...] space-filling curves. > Geohashes of
by V__ 3y ago
> [Geohash] subdivides space into buckets of grid shape, which is one of the many applications of what is known as a [...] space-filling curves.
> Geohashes offer properties like arbitrary precision and the possibility of gradually removing characters from the end of the code to reduce its size (and gradually lose precision).
This is really cool and obvious reading it, but I somehow never thought about it that way. Are space-filling curves used in compression?
- jandrewrogers 3y agoAny regular space decomposition can be described in terms of a space-filling curve. However, there is little benefit in doing so in practice so you rarely see it expressed that way. They were briefly used by major database vendors 30+ years ago for indexing on the theory that it could mitigate head seek latency on spinning disk, hence the use of Hilbert curves, but were quickly abandoned without much fanfare because they have a lot of issues for this use case. If you were going to use them today, not that I would recommend it, Morton curves are generally optimal. While space-filling curves are not useful for compression per se, they are commonly used in some data compression algorithms to convert multi-dimensional data structures (e.g. rasters) into a 1-dimensional byte stream for the compressor.
- jasonwatkinspdx 3y agoNot really for compression, but they are used for GIS indexing in databases.