Module gsi 

Geospatial Information Authority of Japan (GSI / 国土地理院) DEM tile encoding.

Each pixel packs a signed 24-bit integer of 0.01 m units. The no-data sentinel (128, 0, 0) decodes to NaN.

Reference: https://maps.gsi.go.jp/development/demtile.html

Constants

SENTINEL_RGB

No-data sentinel (R=128, G=0, B=0), decoded as NaN.

Functions

decode

Decode RGB bytes into a freshly allocated Vec<f32>.

decode_into

Decode RGB bytes into a caller-owned f32 buffer (no allocation).

decode_pixel

Decode a single GSI (R, G, B) pixel into elevation (metres).

encode

Encode elevations into a freshly allocated Vec<u8>.

encode_into

Encode elevations into a caller-owned RGB buffer (no allocation).

encode_pixel

Encode a single elevation sample (metres) into GSI (R, G, B).

encode_to

Stream-encode elevations to a writer.