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@camera.ui/sdk / sensor / LicensePlateDetectorSensor

Abstract Class: LicensePlateDetectorSensor<TStorage> ​

Defined in: sensor/licensePlate.ts:157

License plate detector that receives video frames from the backend pipeline. Extend this class and implement detectLicensePlates for plate detection and OCR.

Extends ​

Type Parameters ​

TStorage ​

TStorage extends object = Record<string, any>

Constructors ​

Constructor ​

new LicensePlateDetectorSensor<TStorage>(name?): LicensePlateDetectorSensor<TStorage>

Defined in: sensor/licensePlate.ts:60

Parameters ​

name? ​

string = 'License Plate Sensor'

Returns ​

LicensePlateDetectorSensor<TStorage>

Inherited from ​

LicensePlateSensor.constructor

Properties ​

_requiresFrames ​

_requiresFrames: boolean = true

Defined in: sensor/licensePlate.ts:158

Overrides ​

LicensePlateSensor._requiresFrames

category ​

readonly category: Sensor = SensorCategory.Sensor

Defined in: sensor/licensePlate.ts:58

Inherited from ​

LicensePlateSensor.category

id ​

readonly id: string

Defined in: sensor/base.ts:190

Inherited from ​

Sensor.id

name ​

readonly name: string

Defined in: sensor/base.ts:189

Inherited from ​

Sensor.name

onAssignmentChanged ​

readonly onAssignmentChanged: Observable<boolean>

Defined in: sensor/base.ts:209

Inherited from ​

ClipDetectorSensor.onAssignmentChanged

onCapabilitiesChanged ​

readonly onCapabilitiesChanged: Observable<string[]>

Defined in: sensor/base.ts:200

Observable for capability changes. Emits the full capabilities array when capabilities change.

Inherited from ​

LicensePlateSensor.onCapabilitiesChanged

onPropertyChanged ​

readonly onPropertyChanged: Observable<PropertyChangeOf<LicensePlateSensorProperties>>

Defined in: sensor/base.ts:198

Observable for property changes. Emits { property, value, timestamp } when any property changes.

Inherited from ​

LicensePlateSensor.onPropertyChanged

type ​

readonly type: LicensePlate = SensorType.LicensePlate

Defined in: sensor/licensePlate.ts:57

Inherited from ​

LicensePlateSensor.type

Accessors ​

cameraId ​

Get Signature ​

get cameraId(): string

Defined in: sensor/base.ts:257

Camera ID this sensor belongs to. Throws if sensor not yet added to a camera.

Returns ​

string

Inherited from ​

ClipDetectorSensor.cameraId

capabilities ​

Get Signature ​

get capabilities(): TCapability[]

Defined in: sensor/base.ts:277

Optional feature flags advertised by this sensor (e.g., PTZ pan/tilt/zoom)

Returns ​

TCapability[]

Set Signature ​

set capabilities(value): void

Defined in: sensor/base.ts:282

Set capabilities and notify the backend. Automatically deduplicates.

Parameters ​
value ​

TCapability[]

Returns ​

void

Inherited from ​

LicensePlateSensor.capabilities

detected ​

Get Signature ​

get detected(): boolean

Defined in: sensor/licensePlate.ts:70

Whether any license plate is currently detected.

Returns ​

boolean

Inherited from ​

LicensePlateSensor.detected

detections ​

Get Signature ​

get detections(): LicensePlateDetection[]

Defined in: sensor/licensePlate.ts:75

Current detection list.

Returns ​

LicensePlateDetection[]

Inherited from ​

LicensePlateSensor.detections

displayName ​

Get Signature ​

get displayName(): string

Defined in: sensor/base.ts:233

Returns ​

string

Inherited from ​

Sensor.displayName

isAssigned ​

Get Signature ​

get isAssigned(): boolean

Defined in: sensor/base.ts:252

Whether this sensor has been assigned to a camera in the backend

Returns ​

boolean

Inherited from ​

ClipDetectorSensor.isAssigned

modelSpec ​

Get Signature ​

get abstract modelSpec(): ModelSpec

Defined in: sensor/licensePlate.ts:161

Declares the expected input dimensions and trigger labels. The backend scales frames to match.

Returns ​

ModelSpec

pluginId ​

Get Signature ​

get pluginId(): string | undefined

Defined in: sensor/base.ts:264

Returns ​

string | undefined

Inherited from ​

Sensor.pluginId

props ​

Get Signature ​

get protected props(): Readonly<TProperties>

Defined in: sensor/base.ts:295

Read-only access to the internal property store. Subclasses use this to read current state when implementing semantic methods (e.g., if (this.blocked) return).

Returns ​

Readonly<TProperties>

Inherited from ​

LicensePlateSensor.props

storage ​

Get Signature ​

get storage(): DeviceStorage<TStorage>

Defined in: sensor/base.ts:269

Per-sensor persistent storage. Throws if sensor not yet added to a camera.

Returns ​

DeviceStorage<TStorage>

Inherited from ​

LicensePlateSensor.storage

storageSchema ​

Get Signature ​

get storageSchema(): JsonSchema[]

Defined in: sensor/base.ts:216

Override to provide a JSON schema for per-sensor storage settings UI

Returns ​

JsonSchema[]

Inherited from ​

ClipDetectorSensor.storageSchema

Methods ​

clearDetections() ​

clearDetections(): void

Defined in: sensor/licensePlate.ts:122

Explicitly clear license plate state (detected = false, detections = []).

Returns ​

void

Example ​

ts
sensor.clearDetections();

Inherited from ​

LicensePlateSensor.clearDetections

detectLicensePlates() ​

abstract detectLicensePlates(frames): Promise<LicensePlateResult[]>

Defined in: sensor/licensePlate.ts:168

Detect license plates in batch. Each frame is a pre-cropped, pre-scaled vehicle region produced by the upstream object detector. Must return exactly one LicensePlateResult per input frame, in the same order.

Parameters ​

frames ​

VideoFrameData[]

Returns ​

Promise<LicensePlateResult[]>

getValue() ​

Call Signature ​

getValue<K>(property): LicensePlateSensorProperties[K] | undefined

Defined in: sensor/base.ts:303

Get the current value of a sensor property. Type-safe via the generic overload — call with a property enum value to get a properly typed result.

Type Parameters ​
K ​

K extends keyof LicensePlateSensorProperties

Parameters ​
property ​

K

Returns ​

LicensePlateSensorProperties[K] | undefined

Inherited from ​

LicensePlateSensor.getValue

Call Signature ​

getValue(property): unknown

Defined in: sensor/base.ts:304

Get the current value of a sensor property. Type-safe via the generic overload — call with a property enum value to get a properly typed result.

Parameters ​
property ​

string

Returns ​

unknown

Inherited from ​

LicensePlateSensor.getValue

getValues() ​

getValues(): Readonly<TProperties>

Defined in: sensor/base.ts:320

Get a read-only snapshot of all property values.

Returns ​

Readonly<TProperties>

Frozen view of every property currently held by the sensor.

Example ​

ts
const snapshot = sensor.getValues();
console.log(snapshot);

Inherited from ​

LicensePlateSensor.getValues

hasCapability() ​

hasCapability(capability): boolean

Defined in: sensor/base.ts:423

Parameters ​

capability ​

string

Returns ​

boolean

Inherited from ​

LicensePlateSensor.hasCapability

onAssigned() ​

protected onAssigned(): void | Promise<void>

Defined in: sensor/base.ts:473

Lifecycle hook: the sensor just became assigned to a camera. Override to start background work that should only run while this sensor is live — polling loops, event subscriptions, timers, external connections.

Called AFTER cameraId, storage, and RPC channels are wired up, so the override can safely access this.cameraId, this.storage, and publish properties via the semantic helper methods.

Errors thrown here are caught and logged — they will NOT break assignment bookkeeping. If your work can fail, handle it inside the override.

Paired 1:1 with onDeassigned — for every onAssigned call there is exactly one matching onDeassigned later (on deassignment or cleanup).

Default: no-op. Most sensors don't need lifecycle hooks.

Returns ​

void | Promise<void>

Example ​

ts
protected override async onAssigned(): Promise<void> {
  this._timer = setInterval(() => this.poll(), 5_000);
}

Inherited from ​

LicensePlateSensor.onAssigned

onDeassigned() ​

protected onDeassigned(): void | Promise<void>

Defined in: sensor/base.ts:493

Lifecycle hook: the sensor is being deassigned. Override to tear down whatever was started in onAssigned — clear timers, close subscriptions, release external resources.

Always called exactly once for each prior onAssigned. Also called from _cleanup if the sensor is being removed while still assigned, so you can rely on this as the single teardown point.

Default: no-op.

Returns ​

void | Promise<void>

Example ​

ts
protected override onDeassigned(): void {
  if (this._timer) clearInterval(this._timer);
}

Inherited from ​

LicensePlateSensor.onDeassigned

reportDetections() ​

reportDetections(detected, detections?): void

Defined in: sensor/licensePlate.ts:106

Report detected license plates.

  • reportDetections(true) — plate detected without specifics. The SDK synthesizes a single full-frame detection with empty plateText.
  • reportDetections(true, [...]) — explicit plate detections with OCR text.
  • reportDetections(false) — clear.

Parameters ​

detected ​

boolean

Whether any license plate is currently detected.

detections? ​

LicensePlateDetection[]

Optional explicit plate detections to publish.

Returns ​

void

Example ​

ts
import type { LicensePlateDetection } from '@camera.ui/sdk';
sensor.reportDetections(true, [
  {
    label: 'vehicle',
    confidence: 0.93,
    box: { x: 0.2, y: 0.5, width: 0.2, height: 0.08 },
    attribute: 'license_plate',
    plateText: 'ABC 1234',
  } satisfies LicensePlateDetection,
]);
sensor.reportDetections(false);

Inherited from ​

LicensePlateSensor.reportDetections

setDisplayName() ​

setDisplayName(value): void

Defined in: sensor/base.ts:247

Set the display name (the only mutable identifier on a sensor).

Parameters ​

value ​

string

Human-readable label shown in the UI.

Returns ​

void

Example ​

ts
sensor.setDisplayName('Front Door Motion');

Inherited from ​

LicensePlateSensor.setDisplayName