mirror of
https://github.com/snapotter-hq/SnapOtter.git
synced 2026-08-03 07:46:42 +02:00
63 lines
2.1 KiB
Markdown
63 lines
2.1 KiB
Markdown
---
|
|
description: Generate an RGB histogram chart with per-channel statistics from an image.
|
|
---
|
|
|
|
# Histogram
|
|
|
|
Generate an RGB histogram chart from an image. Returns a PNG histogram image along with per-channel statistics and raw 256-bin histogram data in the response JSON.
|
|
|
|
## API Endpoint
|
|
|
|
`POST /api/v1/tools/image/histogram`
|
|
|
|
Accepts multipart form data with an image file and a JSON `settings` field.
|
|
|
|
## Parameters
|
|
|
|
| Parameter | Type | Required | Default | Description |
|
|
|-----------|------|----------|---------|-------------|
|
|
| scale | string | No | `"linear"` | Y-axis scale: `linear` or `log` |
|
|
|
|
## Example Request
|
|
|
|
```bash
|
|
curl -X POST http://localhost:1349/api/v1/tools/image/histogram \
|
|
-H "Authorization: Bearer si_your-api-key" \
|
|
-F "file=@photo.jpg" \
|
|
-F 'settings={"scale": "linear"}'
|
|
```
|
|
|
|
## Example Response
|
|
|
|
```json
|
|
{
|
|
"jobId": "a1b2c3d4-e5f6-7890-abcd-ef1234567890",
|
|
"downloadUrl": "/api/v1/download/a1b2c3d4-e5f6-7890-abcd-ef1234567890/histogram.png",
|
|
"originalSize": 2450000,
|
|
"processedSize": 12000,
|
|
"bins": {
|
|
"r": [0, 12, 45, "... (256 values)"],
|
|
"g": [0, 8, 38, "... (256 values)"],
|
|
"b": [2, 15, 52, "... (256 values)"],
|
|
"lum": [0, 10, 40, "... (256 values)"]
|
|
},
|
|
"stats": {
|
|
"r": { "mean": 128, "median": 132, "stdev": 48.5 },
|
|
"g": { "mean": 119, "median": 121, "stdev": 44.2 },
|
|
"b": { "mean": 105, "median": 108, "stdev": 51.3 },
|
|
"lum": { "mean": 118, "median": 120, "stdev": 45.1 }
|
|
},
|
|
"mean": { "r": 128, "g": 119, "b": 105 },
|
|
"max": { "r": 4200, "g": 3800, "b": 4100 }
|
|
}
|
|
```
|
|
|
|
## Notes
|
|
|
|
- The `downloadUrl` points to a rendered PNG histogram chart showing the R, G, B, and luminance distributions.
|
|
- `bins` contains raw 256-value arrays for each channel (red, green, blue, luminance), suitable for rendering custom visualizations.
|
|
- `stats` provides mean, median, and standard deviation per channel.
|
|
- `mean` and `max` are backward-compatible shorthand fields.
|
|
- Use `log` scale when the histogram is dominated by a few peaks and you want to see detail in the lower bins.
|
|
- HEIC, RAW, PSD, and SVG inputs are automatically decoded before analysis.
|