Image Sink

The image sink saves binary camera frame payloads (JPEG or PNG) directly to local storage directories with automated age-based (maxAge) and count-based (maxCount) retention pruning.

In rekuiper, the Image sink is a built-in component that writes image files using asynchronous disk operations.

Configuration Properties

Configure the image sink action using the following properties:

Property Name	Type	Required	Default	Description
path	String	Yes	-	Target directory path for saved images (e.g. /tmp/images or /tmp/images/{{.deviceId}}).
format	String	No	jpeg	Image format: jpeg, jpg, or png.
imageField	String	No	auto	Name of the field containing binary bytes or a base64 encoded string. If omitted, searches image, image_bytes, data, and payload.
fileName	String	No	auto	Optional file name template (e.g. frame_{{.deviceId}}_{{.ts}}.png). If omitted, generates uuid.format.
maxAge	Integer	No	72	Maximum retention time in hours. Files older than this threshold are pruned.
maxCount	Integer	No	1000	Maximum number of stored image files in the target directory. When exceeded, the oldest files are removed.

Examples

Storing Frame with Dynamic Path and Custom Name

Writes frames from camera streams into device-specific directories with custom file names:

{
  "id": "rule_camera_save",
  "sql": "SELECT deviceId, image, ts FROM cameraStream",
  "actions": [
    {
      "image": {
        "path": "/data/captures/{{.deviceId}}",
        "format": "png",
        "imageField": "image",
        "fileName": "{{.deviceId}}_{{.ts}}.png",
        "maxAge": 24,
        "maxCount": 500
      }
    }
  ]
}