Image Watermark
Overlay a logo or secondary image as a watermark on a base image. The watermark is scaled relative to the base image width and positioned at a corner or center.
API Endpoint
POST /api/v1/tools/watermark-image
Accepts multipart form data with two image files and a JSON settings field.
Parameters
| Parameter | Type | Required | Default | Description |
|---|---|---|---|---|
| position | string | No | "bottom-right" | Watermark placement: center, top-left, top-right, bottom-left, bottom-right |
| opacity | number | No | 50 | Watermark opacity percentage (0 to 100) |
| scale | number | No | 25 | Watermark width as percentage of main image width (1 to 100) |
File Fields
| Field Name | Required | Description |
|---|---|---|
| file | Yes | The main/base image |
| watermark | Yes | The watermark/logo image |
Example Request
bash
curl -X POST http://localhost:1349/api/v1/tools/watermark-image \
-H "Authorization: Bearer si_your-api-key" \
-F "[email protected]" \
-F "[email protected]" \
-F 'settings={"position": "bottom-right", "opacity": 60, "scale": 20}'Example Response
json
{
"jobId": "a1b2c3d4-e5f6-7890-abcd-ef1234567890",
"downloadUrl": "/api/v1/download/a1b2c3d4-e5f6-7890-abcd-ef1234567890/photo.jpg",
"originalSize": 2450000,
"processedSize": 2520000
}Notes
- Both images are validated and decoded (HEIC, RAW, PSD, SVG supported).
- The watermark is resized proportionally so its width equals
scale% of the main image width. - Opacity is applied via an alpha mask composited with
dest-inblending. - Corner positions use a 20px padding from the image edge.
- If the watermark image has transparency (e.g., a PNG logo), it is preserved during compositing.
- EXIF orientation is auto-applied on both images before processing.