temporal_bandpass — MOTIONMAG `temporal` op

• 数据种类:video → video

• 调用:import motionmag; motionmag.temporal_bandpass(video, f_lo, f_hi, fps) -> 'np.ndarray'(或 opsmotionmag.get("temporal_bandpass"))

对每个像素时间序列的理想时间带通 -> `(T, H, W)`。

> 以下的详细说明为原文 —— 摘要与标题已翻译。

Each pixel is transformed along time, every DFT bin whose frequency lies

outside `[f_lo, f_hi]` (in Hz, magnitude, DC always excluded) is zeroed,

and the result is transformed back. Frequency-selective where

`videops.moving_average and videops.spatiotemporal_gaussian` are

low-pass; this is the filter isolating "what is happening at 4 Hz".

Exact for a component sitting on a bin: with `T frames at fps`, a

sinusoid at `k*fps/T` Hz passes with gain 1 and everything else in the band

passes untouched. Measured on a bin-centred 4 Hz unit sinusoid in a 64-frame

32 fps clip that also carries a DC offset of 0.5 and a 12 Hz component of

amplitude 0.3, the recovered waveform matches the 4 Hz term alone to

`max|err| = 4.36e-15`.

A brick-wall filter rings in time; that is the price of an exact pass-band

and it is the same choice the 2012 Eulerian magnification paper makes. The

output is zero-mean along time by construction.

• 示例数据目录(下载 URL / 许可证) —— 2-D 用 skimage.data(BSD/公有领域)加合成图,3-D 给出真实数据源(Stanford/PDS 等)的下载 URL。

• 算子来历与参考文献 —— 该算子族所依据的研究/方法出处。

• 算法的正典(作者・年份)与用途见上面的族使用指南。

• motion_magnification — py -3.11 examples/motion_magnification.py

• poc_motion_magnification — py -3.11 examples/poc_motion_magnification.py

*Provenance: motionmag.py — MOTIONMAG 算子登记表。本条目由 tools/opdocs.py md 自动生成(请勿手工编辑)。*

temporal_bandpass — MOTIONMAG temporal op