VideoGrade

A color-grading and film-look engine for video frames — pure Core Image, zero dependencies. One filter builder drives both a live AVPlayerItem.videoComposition and an offline exporter, so preview and export match by construction.

import VideoGrade

var grade = VideoGrade()
grade.contrast = 1.1
grade.splitShadow = .blue
grade.splitShadowAmount = 0.4
grade.grain = 0.2

let filter = try GradeFilter(grade: grade)
let output = filter.apply(inputImage, time: currentTime)   // CIImage → CIImage

What it does

VideoGrade is a pure-data description; GradeFilter resolves it to Core Image.

• Tone / color: exposure, brightness, contrast, saturation, vibrance, temperature, tint, highlights, shadows, levels (black/white/gamma), tone curves (master + per-channel), clarity, brilliance, dehaze.
• Color grading: split-tone (shadow/highlight tints), a per-hue B&W mixer, full 12-band HSL, skin-tone protection.
• Film look: fade, grain, glow/bloom, halation, filmic highlight rolloff, light leaks, anamorphic flare, film damage, chromatic aberration, vignette.
• LUTs: .cube files and PNG "HALD"/square LUTs; Adobe Lightroom .xmp develop presets mapped onto the grade.
• Skin smoothing (SkinSmoothFilter) and cut-transition effects (CutRender — dip to black/white, punch-in, whip-pan, zoom-blur, glitch).

The heavy per-pixel work (B&W mixer, 12-band HSL, split-tone, skin tone, curves, brilliance, dehaze) is baked once into a single 32³ CIColorCube (ColorGradeCube); spatial effects (blur, unsharp, bloom, gradients) are Core Image filter stages. Animated effects (grain, light leaks, film damage) read a time: parameter so they move frame to frame.

Notes

• Parity is the consumer's job: build the filter once and use the same instance for preview and export. A footage effect that looks different in the two is a bug in the host's stage ordering, not here.
• Colors are GradeColor (plain sRGB components), serialized as {red, green, blue, alpha} — the same shape as CaptionKit's StyleColor, so grades embedded in existing documents keep decoding after this split.
• Several algorithms are re-authored from the author-owned FilterSpark shaders as Core Image (no Metal/metallib). brilliance/dehaze are pixel-exact ports; the 12-band HSL uses standard wrapped hue.

The UI product

VideoGradeUI is a separate library product — SwiftUI controls that bind to a Binding<VideoGrade>: a curves graph, split-tone wheels, a B&W hue bar, a 12-band HSL editor, and a levels ramp. Separate so the engine stays headless for non-UI consumers.

Requirements

macOS 26 / iOS 26, Swift 6.2. No external dependencies.

Tests

swift test

License

MIT — see LICENSE.

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This project is independent and is not affiliated with, endorsed by, or sponsored by Adobe Inc. Adobe and Lightroom are trademarks of Adobe Inc., registered in the U.S. and other countries.