dem_hillshade — DEM shading op

• Data kinds: depth → image2d

• Call: import demops; demops.dem_hillshade(dem, cell_size, azimuth_deg=315.0, altitude_deg=45.0, z_factor=1.0, method='horn') (or opsdem.get("dem_hillshade"))

Usage

> This operator's description has not been translated yet. The original text follows as it is.

陰影起伏 [0,1]。`azimuth_deg` は光源の方位(北 0 度・東回り)。

Lambert の余弦則そのもので、遮蔽は考えない(自分より手前の尾根で

影になる分は含まれない)。落ちる影が要るなら :func:dem_horizon_angle と

組み合わせること —— 「陰影起伏に影が入っている」と思い込むのが定番の誤解。

平坦面では `sin(altitude)` に一致する(実測 1e-15 以下)。

Detailed usage guide

• dem_terrain_analysis family guide

References (sample data, literature)

• Sample-data catalog (download URLs / licences) — 2-D uses skimage.data (BSD/public domain) plus synthetic images; 3-D lists download URLs for real data sources (Stanford, PDS, …).

• Operator provenance and references — the sources of the research/methods this op family came from.

• The canonical algorithm (author, year) and its uses are named in the family usage guide above.

Runnable examples (verified samples that actually call this op)

• poc_dem_terrain — py -3.11 examples/poc_dem_terrain.py

Ops the type connects to (they accept image2d as input)

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Same category (shading)

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*Provenance: demops.py — DEM operator registry. This per-op note is generated by tools/opdocs.py md (do not hand-edit).*

© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.