selfmotion op• データ種: table → matrix
• 呼び出し: import fullseye as fs; fs.ledger.fly_matched_filter(lattice, axis=(0.0, 0.0, 1.0), motion='rotation', depth_m=1.0) (実装を直接呼ぶなら import flyvision; flyvision.fly_matched_filter(lattice, axis=(0.0, 0.0, 1.0), motion='rotation', depth_m=1.0)、台帳から引くなら opsflyvision.get("fly_matched_filter"))
The flow field one unit of self-motion writes on the eye — the template a wide-field neuron is matched to.
Krapp & Hengstenberg measured the local motion sensitivity of single lobula-plate tangential cells across the whole visual field and found a structured vector field, one that looks like the optic flow of a particular rotation of the fly (*Nature* 384:463, 1996). Reading self-motion out of such a cell is then a matched filter (Franz & Krapp, *Biol. Cybern.* 83:185, 2000):
correlate the measured flow against the template of the motion you are asking about. This op builds the template, for the isotropic world model — every point at the same distance — which is the case in which the rotation template is exactly the geometry and nothing is assumed about the scene:
• motion="rotation": one radian per second about the unit vector *axis* moves the viewing direction d at -axis x d, which is already tangent to the sphere. Its length is sin of the angle between the axis and the line of sight, so the template is zero on the axis itself.
• motion="translation": one metre per second along *axis*, with every point at *depth_m* metres, moves it at -(v - (v.d) d)/Z. The depth is an input, not a measurement — translation flow and distance are the same unknown and no eye can separate them from one frame pair.
lattice: a fly_hex_lattice result. axis: the rotation axis or translation direction in body coordinates (x forward, y left, z up); it is normalised, and a zero vector is refused. depth_m: the uniform distance, motion="translation" only.
Returns (n, 2) float64 — the azimuth and elevation components of the flow at each ommatidium, in radians per second, the same layout fly_flow_from_directions returns.
Ground truth: for a rotation, |f| = sin(angle(axis, d)) exactly, so it is 0 where the line of sight is along the axis and 1 where it is perpendicular; and the flow is perpendicular to both the axis and the line of sight. For a translation, |f| = sin(angle)/depth and the flow points away from the direction of travel (the focus of expansion is where the template vanishes).
Raises ValueError: a malformed *lattice*, an *axis* that is not three finite numbers or is zero-length, an unknown *motion*, and a non-positive *depth_m*.
• 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。
• poc_fly_optomotor_steering — py -3.11 examples/poc_fly_optomotor_steering.py
matrix を入力に取れる)fly_lamina_filter · fly_onoff_split · fly_t4t5_field · fly_flow_from_directions · fly_egomotion_from_flow · fly_hs_readout
selfmotion)fly_egomotion_from_flow · fly_eye_merge
*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.