react-native-vision-camera/docs/docs/api/index.md

id	title	sidebar_label	sidebar_position	custom_edit_url
index	VisionCamera	Overview	0.5	null

Classes

• Camera
• CameraCaptureError
• CameraRuntimeError

Interfaces

• CameraDevice
• CameraDeviceFormat
• CameraProps
• ErrorWithCause
• PhotoFile
• Point
• RecordVideoOptions
• TakePhotoOptions
• TemporaryFile
• VideoFile

Type Aliases

AutoFocusSystem

Ƭ AutoFocusSystem: "contrast-detection" | "phase-detection" | "none"

Indicates a format's autofocus system.

• "none": Indicates that autofocus is not available
• "contrast-detection": Indicates that autofocus is achieved by contrast detection. Contrast detection performs a focus scan to find the optimal position
• "phase-detection": Indicates that autofocus is achieved by phase detection. Phase detection has the ability to achieve focus in many cases without a focus scan. Phase detection autofocus is typically less visually intrusive than contrast detection autofocus

Defined in

CameraDevice.ts:53

---

CameraDevices

Ƭ CameraDevices: { [key in CameraPosition]: CameraDevice | undefined }

Defined in

hooks/useCameraDevices.ts:7

---

CameraPermissionRequestResult

Ƭ CameraPermissionRequestResult: "granted" | "denied"

Defined in

Camera.tsx:15

---

CameraPermissionStatus

Ƭ CameraPermissionStatus: "granted" | "not-determined" | "denied" | "restricted"

Defined in

Camera.tsx:14

---

CameraPosition

Ƭ CameraPosition: "front" | "back" | "unspecified" | "external"

Represents the camera device position.

• "back": Indicates that the device is physically located on the back of the system hardware
• "front": Indicates that the device is physically located on the front of the system hardware

iOS only

• "unspecified": Indicates that the device's position relative to the system hardware is unspecified

Android only

• "external": The camera device is an external camera, and has no fixed facing relative to the device's screen. (Android only)

Defined in

CameraPosition.ts:13

---

CaptureError

Ƭ CaptureError: "capture/invalid-photo-format" | "capture/encoder-error" | "capture/muxer-error" | "capture/recording-in-progress" | "capture/no-recording-in-progress" | "capture/file-io-error" | "capture/create-temp-file-error" | "capture/invalid-video-options" | "capture/create-recorder-error" | "capture/recorder-error" | "capture/no-valid-data" | "capture/inactive-source" | "capture/insufficient-storage" | "capture/file-size-limit-reached" | "capture/invalid-photo-codec" | "capture/not-bound-error" | "capture/capture-type-not-supported" | "capture/video-not-enabled" | "capture/photo-not-enabled" | "capture/aborted" | "capture/unknown"

Defined in

CameraError.ts:31

---

DeviceError

Ƭ DeviceError: "device/configuration-error" | "device/no-device" | "device/invalid-device" | "device/torch-unavailable" | "device/microphone-unavailable" | "device/pixel-format-not-supported" | "device/low-light-boost-not-supported" | "device/focus-not-supported" | "device/camera-not-available-on-simulator"

Defined in

CameraError.ts:8

---

FormatError

Ƭ FormatError: "format/invalid-fps" | "format/invalid-hdr" | "format/invalid-low-light-boost" | "format/invalid-format" | "format/invalid-color-space"

Defined in

CameraError.ts:18

---

FrameProcessor

Ƭ FrameProcessor: Object

Type declaration

Name	Type
frameProcessor	(frame: Frame) => void
type	"frame-processor"

Defined in

CameraProps.ts:7

---

LogicalCameraDeviceType

Ƭ LogicalCameraDeviceType: "dual-camera" | "dual-wide-camera" | "triple-camera"

Indentifiers for a logical camera (Combinations of multiple physical cameras to create a single logical camera).

• "dual-camera": A combination of wide-angle and telephoto cameras that creates a capture device.
• "dual-wide-camera": A device that consists of two cameras of fixed focal length, one ultrawide angle and one wide angle.
• "triple-camera": A device that consists of three cameras of fixed focal length, one ultrawide angle, one wide angle, and one telephoto.

Defined in

CameraDevice.ts:21

---

ParameterError

Ƭ ParameterError: "parameter/invalid-parameter" | "parameter/unsupported-os" | "parameter/unsupported-output" | "parameter/unsupported-input" | "parameter/invalid-combination"

Defined in

CameraError.ts:2

---

PermissionError

Ƭ PermissionError: "permission/microphone-permission-denied" | "permission/camera-permission-denied"

Defined in

CameraError.ts:1

---

PhysicalCameraDeviceType

Ƭ PhysicalCameraDeviceType: "ultra-wide-angle-camera" | "wide-angle-camera" | "telephoto-camera"

Indentifiers for a physical camera (one that actually exists on the back/front of the device)

• "ultra-wide-angle-camera": A built-in camera with a shorter focal length than that of a wide-angle camera. (focal length between below 24mm)
• "wide-angle-camera": A built-in wide-angle camera. (focal length between 24mm and 35mm)
• "telephoto-camera": A built-in camera device with a longer focal length than a wide-angle camera. (focal length between above 85mm)

Defined in

CameraDevice.ts:12

---

SessionError

Ƭ SessionError: "session/camera-not-ready" | "session/camera-cannot-be-opened" | "session/camera-has-been-disconnected" | "session/audio-session-setup-failed" | "session/audio-in-use-by-other-app" | "session/audio-session-failed-to-activate"

Defined in

CameraError.ts:24

---

SystemError

Ƭ SystemError: "system/camera-module-not-found" | "system/no-camera-manager" | "system/frame-processors-unavailable" | "system/view-not-found"

Defined in

CameraError.ts:53

---

UnknownError

Ƭ UnknownError: "unknown/unknown"

Defined in

CameraError.ts:58

---

VideoStabilizationMode

Ƭ VideoStabilizationMode: "off" | "standard" | "cinematic" | "cinematic-extended" | "auto"

Indicates a format's supported video stabilization mode. Enabling video stabilization may introduce additional latency into the video capture pipeline.

• "off": No video stabilization. Indicates that video should not be stabilized
• "standard": Standard software-based video stabilization. Standard video stabilization reduces the field of view by about 10%.
• "cinematic": Advanced software-based video stabilization. This applies more aggressive cropping or transformations than standard.
• "cinematic-extended": Extended software- and hardware-based stabilization that aggressively crops and transforms the video to apply a smooth cinematic stabilization.
• "auto": Indicates that the most appropriate video stabilization mode for the device and format should be chosen automatically

Defined in

CameraDevice.ts:64

Variables

VisionCameraProxy

• Const VisionCameraProxy: TVisionCameraProxy = proxy

Defined in

FrameProcessorPlugins.ts:95

Functions

createFrameProcessor

▸ createFrameProcessor(frameProcessor, type): FrameProcessor

Create a new Frame Processor function which you can pass to the <Camera>. (See "Frame Processors")

Make sure to add the 'worklet' directive to the top of the Frame Processor function, otherwise it will not get compiled into a worklet.

Also make sure to memoize the returned object, so that the Camera doesn't reset the Frame Processor Context each time.

Parameters

Name	Type
frameProcessor	(frame: Frame) => void
type	"frame-processor"

Returns

FrameProcessor

Defined in

hooks/useFrameProcessor.ts:13

---

isErrorWithCause

▸ isErrorWithCause(error): error is ErrorWithCause

Checks if the given error is of type ErrorWithCause

Parameters

Name	Type	Description
error	unknown	Any unknown object to validate

Returns

error is ErrorWithCause

true if the given error is of type ErrorWithCause

Defined in

CameraError.ts:176

---

parsePhysicalDeviceTypes

▸ parsePhysicalDeviceTypes(physicalDeviceTypes): PhysicalCameraDeviceType | LogicalCameraDeviceType

Parses an array of physical device types into a single PhysicalCameraDeviceType or LogicalCameraDeviceType, depending what matches.

Method

Parameters

Name	Type
physicalDeviceTypes	PhysicalCameraDeviceType[]

Returns

PhysicalCameraDeviceType | LogicalCameraDeviceType

Defined in

CameraDevice.ts:27

---

runAsync

▸ runAsync(frame, func): void

Runs the given function asynchronously, while keeping a strong reference to the Frame.

For example, if you want to run a heavy face detection algorithm while still drawing to the screen at 60 FPS, you can use runAsync(...) to offload the face detection algorithm to a separate thread.

Example

const frameProcessor = useFrameProcessor((frame) => {
  'worklet'
  console.log('New Frame')
  runAsync(frame, () => {
    'worklet'
    const faces = detectFaces(frame)
    const face = [faces0]
    console.log(`Detected a new face: ${face}`)
  })
})

Parameters

Name	Type	Description
frame	Frame	The current Frame of the Frame Processor.
func	() => void	The function to execute.

Returns

void

Defined in

FrameProcessorPlugins.ts:177

---

runAtTargetFps

▸ runAtTargetFps<T>(fps, func): T | undefined

Runs the given function at the given target FPS rate.

For example, if you want to run a heavy face detection algorithm only once per second, you can use runAtTargetFps(1, ...) to throttle it to 1 FPS.

Example

const frameProcessor = useFrameProcessor((frame) => {
  'worklet'
  console.log('New Frame')
  runAtTargetFps(5, () => {
    'worklet'
    const faces = detectFaces(frame)
    console.log(`Detected a new face: ${faces[0]}`)
  })
})

Type parameters

Name
T

Parameters

Name	Type	Description
fps	number	The target FPS rate at which the given function should be executed
func	() => T	The function to execute.

Returns

T | undefined

The result of the function if it was executed, or undefined otherwise.

Defined in

FrameProcessorPlugins.ts:136

---

sortDevices

▸ sortDevices(left, right): number

Compares two devices by the following criteria:

• wide-angle-cameras are ranked higher than others
• Devices with more physical cameras are ranked higher than ones with less. (e.g. "Triple Camera" > "Wide-Angle Camera")

Note that this makes the sort() function descending, so the first element ([0]) is the "best" device.

Example

const devices = camera.devices.sort(sortDevices)
const bestDevice = devices[0]

Method

Parameters

Name	Type
left	CameraDevice
right	CameraDevice

Returns

number

Defined in

utils/FormatFilter.ts:18

---

sortFormats

▸ sortFormats(left, right): number

Sort formats by resolution and aspect ratio difference (to the Screen size).

Note that this makes the sort() function descending, so the first element ([0]) is the "best" device.

Parameters

Name	Type
left	CameraDeviceFormat
right	CameraDeviceFormat

Returns

number

Defined in

utils/FormatFilter.ts:72

---

tryParseNativeCameraError

▸ tryParseNativeCameraError<T>(nativeError): CameraCaptureError | CameraRuntimeError | T

Tries to parse an error coming from native to a typed JS camera error.

Method

Type parameters

Name
T

Parameters

Name	Type	Description
nativeError	T	The native error instance. This is a JSON in the legacy native module architecture.

Returns

CameraCaptureError | CameraRuntimeError | T

A CameraRuntimeError or CameraCaptureError, or the nativeError itself if it's not parsable

Defined in

CameraError.ts:202

---

useCameraDevices

▸ useCameraDevices(): CameraDevices

Gets the best available CameraDevice. Devices with more cameras are preferred.

Throws

CameraRuntimeError if no device was found.

Example

const device = useCameraDevice()
// ...
return <Camera device={device} />

Returns

CameraDevices

The best matching CameraDevice.

Defined in

hooks/useCameraDevices.ts:29

▸ useCameraDevices(deviceType): CameraDevices

Gets a CameraDevice for the requested device type.

Throws

CameraRuntimeError if no device was found.

Example

const device = useCameraDevice('wide-angle-camera')
// ...
return <Camera device={device} />

Parameters

Name	Type	Description
deviceType	PhysicalCameraDeviceType | LogicalCameraDeviceType	Specifies a device type which will be used as a device filter.

Returns

CameraDevices

A CameraDevice for the requested device type.

Defined in

hooks/useCameraDevices.ts:44

---

useCameraFormat

▸ useCameraFormat(device?): CameraDeviceFormat | undefined

Returns the best format for the given camera device.

This function tries to choose a format with the highest possible photo-capture resolution and best matching aspect ratio.

Parameters

Name	Type	Description
device?	CameraDevice	The Camera Device

Returns

CameraDeviceFormat | undefined

The best matching format for the given camera device, or undefined if the camera device is undefined.

Defined in

hooks/useCameraFormat.ts:14

---

useFrameProcessor

▸ useFrameProcessor(frameProcessor, dependencies): FrameProcessor

Returns a memoized Frame Processor function wich you can pass to the <Camera>. (See "Frame Processors")

Make sure to add the 'worklet' directive to the top of the Frame Processor function, otherwise it will not get compiled into a worklet.

Example

const frameProcessor = useFrameProcessor((frame) => {
  'worklet'
  const qrCodes = scanQRCodes(frame)
  console.log(`QR Codes: ${qrCodes}`)
}, [])

Parameters

Name	Type	Description
frameProcessor	(frame: Frame) => void	The Frame Processor
dependencies	DependencyList	The React dependencies which will be copied into the VisionCamera JS-Runtime.

Returns

FrameProcessor

The memoized Frame Processor.

Defined in

hooks/useFrameProcessor.ts:49