Color & Effects

What It Is

Varve provides color management across RGB, CMYK, and grayscale color spaces with ICC profile support. The effects system includes drop shadows, inner shadows, layer blur, background blur, and glow effects. Adjustment layers provide non-destructive editing with curves, levels, selective color, HSL, and exposure controls. The halftone engine supports AM and FM screening for print production.

Key Capabilities

• Color spaces: RGB, CMYK, grayscale, and spot colors with analytical conversion
• ICC profiles: Bundled RGB and CMYK profiles (sRGB, Fogra39, GRACoL, SWOP) with rendering intents
• Blend modes: 18 CSS blend modes plus 4 non-separable modes (hue, saturation, color, luminosity)
• Effects: Drop shadow, inner shadow, layer blur (GPU-accelerated up to 32px, software beyond), background blur, outer and inner glow
• Adjustment layers: Curves (Catmull-Rom spline), levels, selective color (9 targets), HSL, exposure — with per-target scoping
• Halftone screening: AM (clustered-dot, 5 dot shapes) and FM (Floyd-Steinberg + Bayer) with standard CMYK angles
• Soft proofing: CMYK simulation overlay for previewing print output on screen
• Background removal: AI-based removal with u2netp (bundled) and BiRefNet-Lite models, hair edge refinement, subject picker
• Retouching tools: Clone stamp, healing brush, spot heal, patch tool

Technical Depth

Color management uses a ManagedColor discriminated union (RGB/CMYK/Gray/Spot) with analytical sRGB-to-CMYK conversion via OKLab. The blur engine uses separable Gaussian kernels with premultiplied alpha and linear-light compositing for radii above 32px. Adjustment layers support 5 scoping modes for targeting specific layers.

The halftone engine implements ISO 12647-2 standard CMYK screen angles. Background removal runs via an ONNX Runtime pipeline with native desktop support (faster) and WASM worker fallback for web.

Limitations

Status