CodeSampleX

Sample

ImageUtils.sRGBToLinear and Lut extract pixel buffers via CanvasRenderingContext2D.getImageData, converting canvas textures through non-linear sRGB transfer curves that alter all 4 channels including alpha while mapping Lut colormaps top-down.

sha256:9184d8c8837ecc45292b8217132201933dbc175211ff61705b8bf9789e269e7c

Publication state. LOCAL_PASS passed only on its author's machine; PUBLISHED is public and awaiting independent verification; CROSS_PASS was reproduced by another verifier; MATRIX_PASS passed across environment boundaries; STABLE has sustained independent passes without recent failures. Evidence strength. L0 is source only; L1 resolved dependencies; L2 compiled or loaded; L3 passed its contract; L4 was independently reproduced; L5 passed across different environments. MIT-0

Execution evidence

Declared environment and signed verification runs are separated so you can see exactly what this sample proves.

Evidence basis
Independent cross-verification
Verification receipts
2
Verification level
L4_CROSS_PASS
Declared environment node linux x64 node node npm

Verification-run environments

Environment Contract Stages Run
node 22 · linux alpine/x64 · docker ed25519:d91480838ac982c9 PASS compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS
CONTAINER_RUN · node-typescript@1
2026-08-19
node 22 · linux alpine/x64 · docker ed25519:2175b912ea1c23b1 PASS compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS
CONTAINER_RUN · node-typescript@1
2026-08-19

Case

HOW
Goal
ImageUtils.sRGBToLinear and Lut extract pixel buffers via CanvasRenderingContext2D.getImageData, converting canvas textures through non-linear sRGB transfer curves that alter all 4 channels including alpha while mapping Lut colormaps top-down.
Packages
Symbols
  • CanvasRenderingContext2D.getImageData
Environment
node
Created
2026-08-19T13:04:55Z

Contract

  1. ImageUtils.sRGBToLinear extracts canvas pixel data via CanvasRenderingContext2D.getImageData and applies the sRGB-to-linear conversion curve across all 4 channels, transforming translucent alpha values rather than preserving alpha intact.
  2. ImageUtils.sRGBToLinear on HTMLCanvasElement creates a new canvas and puts converted ImageData without mutating the source canvas in place.
  3. ImageUtils.sRGBToLinear on raw byte buffers uses Math.floor truncation while ImageData uses Uint8ClampedArray nearest-integer rounding.
  4. Lut.updateCanvas queries CanvasRenderingContext2D.getImageData for a 1xN buffer and populates color stops from top (y=0, i=1.0) to bottom (y=N-1, i=0.0) with full opacity (alpha=255).
  5. ImageUtils.sRGBToLinear returns unsupported objects directly with a warning when neither canvas interfaces nor data buffers are present.

Files

  • NOTES.md
  • csx.json
  • package-lock.json
  • package.json
  • test/contract.mjs

Download the source artifact (tar.gz)

Origin Seeder

csx-seed