Sharpening
Advanced sharpening tool with three methods: adaptive (smart edge-aware), unsharp mask (classic radius/amount), and high-pass (texture emphasis). Includes built-in noise reduction to prevent sharpening artifacts.
API Endpoint
POST /api/v1/tools/sharpening
Accepts multipart form data with an image file and a JSON settings field.
Parameters
| Parameter | Type | Required | Default | Description |
|---|---|---|---|---|
| method | string | No | "adaptive" | Sharpening algorithm: adaptive, unsharp-mask, high-pass |
| sigma | number | No | 1.0 | Adaptive: Gaussian sigma (0.5 to 10) |
| m1 | number | No | 1.0 | Adaptive: flat area sharpening (0 to 10) |
| m2 | number | No | 3.0 | Adaptive: jagged area sharpening (0 to 20) |
| x1 | number | No | 2.0 | Adaptive: flat/jagged threshold (0 to 10) |
| y2 | number | No | 12 | Adaptive: maximum flat sharpening (0 to 50) |
| y3 | number | No | 20 | Adaptive: maximum jagged sharpening (0 to 50) |
| amount | number | No | 100 | Unsharp mask: sharpening amount (0 to 1000) |
| radius | number | No | 1.0 | Unsharp mask: blur radius in pixels (0.1 to 5) |
| threshold | number | No | 0 | Unsharp mask: minimum brightness difference to sharpen (0 to 255) |
| strength | number | No | 50 | High-pass: filter strength (0 to 100) |
| kernelSize | number | No | 3 | High-pass: convolution kernel size (3 or 5) |
| denoise | string | No | "off" | Pre-sharpening noise reduction: off, light, medium, strong |
Example Request
bash
curl -X POST http://localhost:1349/api/v1/tools/sharpening \
-H "Authorization: Bearer si_your-api-key" \
-F "[email protected]" \
-F 'settings={"method": "adaptive", "sigma": 1.5}'Unsharp mask with threshold to protect smooth areas:
bash
curl -X POST http://localhost:1349/api/v1/tools/sharpening \
-H "Authorization: Bearer si_your-api-key" \
-F "[email protected]" \
-F 'settings={"method": "unsharp-mask", "amount": 150, "radius": 1.5, "threshold": 10}'Example Response
json
{
"jobId": "a1b2c3d4-e5f6-7890-abcd-ef1234567890",
"downloadUrl": "/api/v1/download/a1b2c3d4-e5f6-7890-abcd-ef1234567890/photo.jpg",
"originalSize": 2450000,
"processedSize": 2510000
}Notes
- Only parameters relevant to the chosen method are used. For example,
amount,radius, andthresholdare ignored whenmethodisadaptive. - The adaptive method uses Sharp's built-in adaptive sharpening with configurable flat/jagged region behavior.
- The
denoiseoption applies noise reduction before sharpening to prevent amplification of noise/grain. - High-pass sharpening extracts fine detail by subtracting a blurred version from the original, then blending back.
- Output format matches the input format. HEIC, RAW, PSD, and SVG inputs are automatically decoded before processing.