typed op• 資料種類:signal → signal
• 呼叫:fullseye.apply(img, "tb_fly_lgmd_eta", a=0.5, b=0.5)(2-D 的模型是一張圖 + 兩個純量旋鈕 a,b∈[0,1])
*圖為在 128×128 合成輸入上實際執行的輸出。左為輸入，右為輸出。點雲以俯視散點顯示(亮度 = z)，一維序列為折線，體資料為沿 z 的最大值投影，影片為中間影格，複數影像為振幅；無法成像的回傳值直接顯示數值。*
掃描旋鈕 a(0.1 / 0.5 / 0.9，另一旋鈕取預設):
▸ tb_fly_lgmd_eta: 旋鈕 a 掃描 (文件網站)
*旋鈕 b 不改變輸出(實測: 0.1 / 0.5 / 0.9 相同)。*
階段(前置運算子 → 本運算子，由左至右):
▸ tb_fly_lgmd_eta: 處理階段 (文件網站)
換別的影像(合成場景 / 照片 / 硬幣。上排為輸入，下排為對應輸出。旋鈕取預設):
▸ tb_fly_lgmd_eta: 其他輸入影像 (文件網站)
> 該運算子的說明尚無譯文,以下照原文給出。
LGMD/eta looming response from an expanding subtended angle.
The multiplicative looming model::
eta(t) = theta'(t - delay) * exp(-alpha * theta(t - delay))
where *theta_signal* is the object's full subtended angle over time, in radians. The product of the angular expansion rate and an exponentially decaying gain gives a response that peaks a fixed time before collision.
theta_signal: the full subtended angle per sample, radians.
dt_s: the sample interval, seconds.
alpha: the gain-decay constant.
delay_s: a fixed neural delay, seconds.
Returns a 1-D float64 array eta(t) of the same length.
Ground truth: for an object of half-size l approaching at speed |v|, eta peaks at a time-to-contact of alpha*l/|v| - delay_s (Gabbiani et al. Eq. 5), where the subtended angle is exactly 2*atan(1/alpha) (Eq. 6; 24.0 degrees for alpha = 4.7) — both pinned in the tests.
Raises ValueError: a non-1-D / empty / too-short (< 3) / non-finite *theta_signal*, a signal over MAX_SIGNAL_POINTS, a non-positive *dt_s* / *alpha*, and a negative *delay_s*.
Typed bridge of the flyvision op fly_lgmd_eta into the 2-D evolution registry: the same implementation, called under the op(v, a, b) convention. a drives alpha (default 4.7); b is unused.
• 範例資料目錄(下載 URL / 授權) —— 2-D 用 skimage.data(BSD/公有領域)加合成圖,3-D 給出真實資料源(Stanford/PDS 等)的下載 URL。
• 運算子來歷與參考文獻 —— 該運算子族所依據的研究/方法出處。
下面的程式已確認可以執行(與圖相同的輸入)。在 Studio 說明中，此區塊會變成按鈕，可當場載入並執行。
img_to_signal 0.50 0.50 tb_fly_lgmd_eta 0.50 0.50
下面的範例呼叫的是底層帳本運算子 fly_lgmd_eta。此橋接運算子只是把同一實作適配為 fn(v, a, b) 慣例，行為完全相同(只是呼叫形式不同)。
• poc_fly_vision — py -3.11 examples/poc_fly_vision.py
signal 作為輸入)identity · tb_create_funct_1d_array · tb_smooth_funct_1d_gauss · tb_smooth_funct_1d_mean · tb_derivate_funct_1d · tb_integrate_funct_1d · tb_zero_crossings_funct_1d · tb_abs_funct_1d
typed)tb_points_to_voxel · tb_estimate_point_normals · tb_iss_keypoints · tb_project_points · tb_render_point_depth · tb_statistical_outlier_removal · tb_radius_outlier_removal · tb_voxel_grid_downsample
*Provenance: ops.py — 2D 運算子登記表。本條目由 tools/opdocs.py md 自動產生(請勿手動編輯)。*
© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.