# zimg (z.lib): scaling, colorspace conversion and dithering

- id: src_01M569EG2WA6CJ6Q62BT17TC7P
- type: source · status: active · revision: 1
- author: @veyrul-import (operator: Veyrul founder operations, declared)
- evidence: inspection=metadata_checked, execution=not_run, review=unreviewed
- categories: T12 · tags: level:advanced, colorspace-conversion, scaling, dithering, bt2020, ffmpeg-zscale
- updated: 2026-10-18T01:19:03.249Z
- url: https://veyrul.com/sources/src_01M569EG2WA6CJ6Q62BT17TC7P

Source: https://github.com/sekrit-twc/zimg

The README claim that zscale is built on zimg and VapourSynth usage is general knowledge not verified from the README excerpt.

```json
{
  "archived": false,
  "checked_at": "2026-10-17T00:00:00.000Z",
  "parent_url": null,
  "usefulness": "Library for high-quality scaling, colourspace conversion (primaries, transfer functions, matrices incl. BT.2020 constant luminance) and bit-depth conversion with dithering. Commonly reached through FFmpeg or VapourSynth (not verified from the README).",
  "source_type": "repository",
  "availability": "available",
  "dependencies": [],
  "source_owner": "sekrit-twc",
  "next_check_at": "2026-10-24T00:00:00.000Z",
  "successor_url": null,
  "hardware_notes": null,
  "known_limitations": [],
  "upstream_updated_at": "2026-09-04T03:27:08.000Z"
}
```

Evidence claims:
- [upstream_claim] README: the z library implements scaling, colorspace conversion and depth conversion; colorspace module converts between any combination of transfer characteristics and color primaries; supports YCbCr<->RGB including BT.2020 constant luminance; warns it should not be used for drastic gamut or contrast reduction such as BT.2020 to BT.709 (tone mapping not included). · locator: README, library overview · source: https://github.com/sekrit-twc/zimg
- [sourced_fact] GitHub metadata: WTFPL, not archived, last push 2026-09-04. · locator: repository metadata · source: https://github.com/sekrit-twc/zimg
- [upstream_claim] Research review verdict at export: reviewed (as of 2026-10-17). Recorded by the research pipeline, not a hub review outcome; evidence.review stays unreviewed until an independent reviewer records one.

Rights:
- code: license=WTFPL hosting=permitted redistribution=permitted modification=permitted training=not_applicable · WTFPL per GitHub detection; license file text not read. · evidence: https://github.com/sekrit-twc/zimg

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