Photo Tone Curves & Profile Processor

Apply levels, RGB curves and white balance, or reuse a Lumina photo profile.

How it works

Develop a photo with black and white points, gamma, five-point master and RGB curves, and linear-light white-balance gains. Download a transparent PNG and reusable settings profile, or paste a profile saved from Lumina.

Auto-oriented, display-referred 8-bit sRGB analysis. Fully transparent pixels are excluded; other pixels count equally.
Luma is rounded 0.2126 R + 0.7152 G + 0.0722 B. Clipping counts any channel at or below 2, or at or above 253. This does not measure sensor exposure or recover clipped RAW data.
A supplied Lumina profile overrides all manual fields. Otherwise apply linear-light RGB gains, existing Develop exposure/contrast/saturation, encoded-sRGB levels and gamma, master curve, then channel curves. Five fixed inputs are interpolated with straight segments; outputs may be non-monotonic.
Gamma uses normalizedInput^(1/gamma). PNG retains the source alpha and omits source metadata. Profiles contain only adjustments and tone settings; camera PP3, RAW and ICC profiles are not supported.

Sources

RawTherapee: photo development workflow inspiration (RawTherapee)
RawPedia: exposure, levels and tone curves (RawTherapee)

For scripts and AI agents

JSON API: POST https://luminatoneprocessor.usefulweb.app/api/v1/calculate (same calculation as this page)
Interface description: OpenAPI 3.1 · AI guide: llms.txt
MCP server (Streamable HTTP): https://luminatoneprocessor.usefulweb.app/mcp · tool name lumina_tone_processor

Example request

curl -s -X POST https://luminatoneprocessor.usefulweb.app/api/v1/calculate \
  -H 'content-type: application/json' \
  -d '{"image":{"filename":"sample.png","contentType":"image/png","contentBase64":"iVBORw0KGgoAAAANSUhEUgAAACAAAAAgAQMAAABJtOi3AAAABlBMVEX/////AADrWueTAAAAEklEQVQI12NgIBb8/09dgjgAAPcnH+GApkH4AAAAAElFTkSuQmCC"},"master":"0,50,128,206,255"}'