watermark_capacity — IMGFORENSICS `watermark` op

• Data kinds: image2d × phash → table

• Call: import imgforensics; imgforensics.watermark_capacity(image, bits, strengths=(0.02, 0.05, 0.1, 0.2, 0.4), wavelet: 'str' = 'haar', level: 'int' = 1, jpeg_quality=None) -> 'dict' (or opsimgforensics.get("watermark_capacity"))

Usage

Sweep the trade-off between embedding strength and PSNR / BER. `table`.

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

各 `strength` について埋め込み → 抽出を実際に走らせ、

`psnr_db 原画像と透かし入り画像の PSNR(値域 [0, 1] 基準、MAX=1`)

`ber 抽出のビット誤り率(:func:hash_distance` で数える)

`clipped` 透かし入り画像が [0, 1] からはみ出した画素の割合。

はみ出しは保存時に必ず失われるので、PSNR だけ見て強度を

上げると「測っていない劣化」が増える

`jpeg_quality` に品質を渡すと、透かし入り画像を 本物の JPEG に通してから

抽出した `ber_jpeg` も入る(Pillow 必須。省略時は列ごと入らない ——

環境によって返る列が変わらないようにするため、既定では走らせない)。

返りは `{"capacity_bits": int, "n_bits": int, "rows": [...], "caveats": [...]}`。

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_forensics_audit — py -3.11 examples/image_forensics_audit.py

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

evidence_quantile

Same category (`watermark`)

watermark_embed · watermark_extract

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

watermark_capacity — IMGFORENSICS watermark op