Duotone

Apply a two-color duotone effect to an image. The image is converted to grayscale, then mapped to a gradient between the shadow color (dark tones) and the highlight color (bright tones).

API Endpoint

POST /api/v1/tools/duotone

Accepts multipart form data with an image file and a JSON settings field.

Parameters

Parameter	Type	Required	Default	Description
shadow	string	No	"#1e3a8a"	Shadow hex color (applied to dark tones)
highlight	string	No	"#fbbf24"	Highlight hex color (applied to bright tones)
intensity	integer	No	100	Effect intensity (0-100); 0 returns the original, 100 applies the full duotone

Example Request

curl -X POST http://localhost:1349/api/v1/tools/duotone \
  -H "Authorization: Bearer si_your-api-key" \
  -F "[email protected]" \
  -F 'settings={"shadow": "#0f172a", "highlight": "#f97316", "intensity": 80}'

Example Response

{
  "jobId": "a1b2c3d4-e5f6-7890-abcd-ef1234567890",
  "downloadUrl": "/api/v1/download/a1b2c3d4-e5f6-7890-abcd-ef1234567890/photo.jpg",
  "originalSize": 2450000,
  "processedSize": 1870000
}

Notes

• Output format matches the input format. HEIC, RAW, PSD, and SVG inputs are automatically decoded before processing.
• An intensity of less than 100 blends the duotone result with the original image, allowing for subtler effects.
• Popular duotone combinations include navy/gold, teal/coral, and purple/pink.