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"))

• GPU: none (CPU reference implementation only)

Usage

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

Integer dtypes (uint8 / uint16 / uint32 / int8 / int16) are uniquely determined by the dtype (other integer dtypes are not guessed, so give data_range explicitly). 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.