bandpass_image — 2D `frequency` op

• Data kinds: image → image

• Call: fullseye.apply(img, "bandpass_image", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])

• HALCON equivalent: bandpass_image (the HALCON reference is a useful guide to its meaning and parameters)

bandpass_image: 入力 → 出力

*The figure is the real output on a synthetic 128×128 input. Left: input, right: output (a non-image return value is shown as the value itself).*

Usage

A band-pass filter that passes only a specified band in the frequency domain (blocking both low and high frequencies), transformed back to real space via inverse FFT. As with `highpass_image, the response is zero-mean and signed, so it is mapped to [0,1] with signed01. Corresponds to HALCON's bandpass_image` (Edge extraction using bandpass filters).

> The detailed description below is the original text — the summary and the headings are translated.

`a が下限カットオフ、b` が上限カットオフを振る。両方が使われる。

帯域(`b` 側の上限)を下限より下に設定すると通過域が空になり出力はほぼ

0.5(ゼロ)一色になる。

Detailed usage guide

• gallery2d_texture_freq 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.

Try it in Studio

The program below has been verified to run (same input as the figure). In Studio's help this block becomes buttons that load and run it on the spot.

bandpass_image 0.40 0.50

▸ Load this pipeline · Load & run

Runnable examples (verified samples that actually call this op)

• gallery2d_texture_freq — py -3.11 examples/gallery2d_texture_freq.py

Ops the type connects to (they accept `image` as input)

identity · gaussian · mean_box · bilateral · unsharp · median · min_filter · max_filter

Same category (`frequency`)

lowpass · highpass · sk_butterworth · fft_image · power_real · power_byte · phase_rad · highpass_image

*Provenance: ops.py — 2D operator registry. This per-op note is generated by tools/opdocs.py md (do not hand-edit).*

bandpass_image — 2D frequency op