data_range_of — IMGMETRICS report op

• Data kinds: image2d → scalar

• Call: import fullseye as fs; fs.ledger.data_range_of(*arrays, data_range=None) (to call the implementation directly, import imgmetrics; imgmetrics.data_range_of(*arrays, data_range=None); from the registry, opsimgmetrics.get("data_range_of"))

Usage

Decide the span the pixel values may take. It does not guess.

For integer dtypes it is uniquely determined by the dtype. Float is treated as 1.0 only when it lies within [0, 1] and otherwise an explicit data_range is required.

Measuring PSNR of a [0, 1] float as if it were 255 is off by 48.13 dB, yet no exception is raised -- only a plausible-looking number comes out, so it is stopped here.

Parameters

*arrays : ndarray

Arrays that should share the same pixel-value convention (usually 2 images).

data_range : float, optional

The range when given explicitly. ValueError unless it is a positive finite value.

Returns

float

Detailed usage guide

• image_difference_metrics 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.

Runnable examples (verified samples that actually call this op)

• image_quality_metrics — py -3.11 examples/image_quality_metrics.py

Ops the type connects to (they accept scalar as input)

luma_limited_u8 · rank_data · tid2013_index

Same category (report)

compare_images · measure_with · metrics_table


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

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