fullseye

fly_sky_1f — FLYVISION stimulus op

• データ種: なし → image2d(引数だけで決まる op —— 画像やデータの入力を取らない)
• 呼び出し: import fullseye as fs; fs.ledger.fly_sky_1f(width=1024, height=512, band_lo_deg=20.0, band_hi_deg=60.0, amp=0.12, seed=0, edge_deg=5.0) (実装を直接呼ぶなら import flyvision; flyvision.fly_sky_1f(width=1024, height=512, band_lo_deg=20.0, band_hi_deg=60.0, amp=0.12, seed=0, edge_deg=5.0)、台帳から引くなら opsflyvision.get("fly_sky_1f"))

使い方

Synthetic equirectangular sky panorama with a banded 1/f azimuthal texture.

An equirectangular image (row = elevation +90 deg down to -90 deg, column = azimuth 0 to 360 deg). Luminance is a vertical backlight gradient (0.62 at the zenith to 0.95 at the nadir) modulated in azimuth by a 1/f texture confined to an elevation band with cosine edges::

L = gradient(el) * (1 + amp * band(el) * noise(az))   clipped to [0, 1]

where noise has unit std, is clipped to +-2, and drops azimuthal frequencies below 2 cycles per revolution; band is 1 inside [band_lo_deg, band_hi_deg] with raised-cosine edges of width edge_deg.

width / height: the panorama size in pixels. band_lo_deg / band_hi_deg / edge_deg: the textured elevation band. amp: the texture contrast on the backlight. seed: integer seed for the azimuth noise (no None).

Returns a float64 (height, width) image in [0, 1].

Ground truth: the standard deviation across azimuth of a row inside the band exceeds that of a row outside it by more than 5x, and the log-log slope of the azimuthal power spectrum of an in-band row is -2 +- 0.4 (both pinned in the tests).

Raises ValueError: width / height outside their caps, a non-real / string / bool parameter, a negative amp, a non-positive edge_deg, and a band that does not satisfy -90 <= band_lo_deg < band_hi_deg <= 90.

参考(サンプルデータ・文献)

• サンプルデータ カタログ(DL URL / ライセンス) — 2-D は skimage.data(BSD/public)+ 合成、3-D は実データ源(Stanford/PDS 等)の DL URL。
• 演算子の来歴・参考文献 — この op 族の元になった研究/手法の出典。
• アルゴリズムの正典(著者・年)と用途は上記ファミリ使い方ガイドに記載。

実行できる例(この op を実際に呼ぶ検証済みサンプル)

• poc_fly_vision — py -3.11 examples/poc_fly_vision.py

型が繋がる次の op(image2d を入力に取れる)

fly_hex_resample

同カテゴリ(stimulus)

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Provenance: flyvision.py — FLYVISION operator registry. この per-op ノートは tools/opdocs.py md が自動生成(手編集しない)。

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

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