48821d50ca
* Move Guides to docs/guides directory * Rename sidebar * Fix api/ links * Update SETUP.mdx
117 lines
5.3 KiB
Plaintext
117 lines
5.3 KiB
Plaintext
---
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id: capturing
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title: Taking Photos/Recording Videos
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sidebar_label: Taking Photos/Recording Videos
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---
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import useBaseUrl from '@docusaurus/useBaseUrl';
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<div>
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<svg xmlns="http://www.w3.org/2000/svg" width="283" height="535" style={{ float: 'right' }}>
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<image href={useBaseUrl("img/demo_capture.gif")} x="18" y="33" width="247" height="469" />
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<image href={useBaseUrl("img/frame.png")} width="283" height="535" />
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</svg>
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</div>
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## Camera Actions
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The Camera provides certain actions using member functions which are available by using a [ref object](https://reactjs.org/docs/refs-and-the-dom.html):
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```tsx
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function App() {
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const camera = useRef<Camera>(null)
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// ...
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return (
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<Camera
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ref={camera}
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{...cameraProps}
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/>
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)
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}
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```
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The most important actions are:
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* [Taking Photos](#taking-photos)
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- [Taking Snapshots](#taking-snapshots)
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* [Recording Videos](#recording-videos)
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* [Focussing](#focussing)
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## Taking Photos
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To take a photo, simply use the Camera's [`takePhoto(...)`](../api/classes/camera.camera-1#takephoto) function:
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```ts
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const photo = await camera.current.takePhoto({
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flash: 'on'
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})
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```
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You can customize capture options such as [automatic red-eye reduction](../api/interfaces/photofile.takephotooptions#enableautoredeyereduction), [automatic image stabilization](../api/interfaces/photofile.takephotooptions#enableautostabilization), [combining images from constituent physical camera devices](../api/interfaces/photofile.takephotooptions#enablevirtualdevicefusion) to create a single high quality fused image, [enable flash](../api/interfaces/photofile.takephotooptions#flash), [prioritize speed over quality](../api/interfaces/photofile.takephotooptions#qualityprioritization) and more using the `options` parameter. (See [`TakePhotoOptions`](../api/interfaces/photofile.takephotooptions))
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This function returns a [`PhotoFile`](../api/interfaces/photofile.photofile-1) which contains a [`path`](../api/interfaces/photofile.photofile-1#path) property you can display in your App using an `<Image>` or `<FastImage>`.
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:::note
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This will change with the upcoming React Native Re-Architecture, so that instead of writing a temporary file which you have to read again, this function will immediately return an Image HostObject on which you can directly interop with the underlying `UIImage`/`Bitmap` for faster image capture. See [issue #69](https://github.com/cuvent/react-native-vision-camera/issues/69)
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:::
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### Taking Snapshots
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Compared to iOS, Cameras on Android tend to be slower in image capture. If you care about speed, you can use the Camera's [`takeSnapshot(...)`](../api/classes/camera.camera-1#takesnapshot) function (Android only) which simply takes a snapshot of the Camera View instead of actually taking a photo through the Camera lens.
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```ts
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const snapshot = await camera.current.takeSnapshot({
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quality: 85,
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skipMetadata: true
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})
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```
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:::note
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While taking Snapshots is faster than taking Photos, the resulting image has way lower quality. You can combine both functions to create a Snapshot for presenting to the User at first, then deliver the actual Photo afterwards.
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:::
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## Recording Videos
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To start a video recording, use the Camera's [`startRecording(...)`](../api/classes/camera.camera-1#startrecording) function:
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```ts
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camera.current.startRecording({
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flash: 'on',
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onRecordingFinished: (video) => console.log(video),
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onRecordingError: (error) => console.error(error),
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})
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```
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For any error that occured _while recording the video_, the `onRecordingError` callback will be invoked with a [`CaptureError`](../api/classes/cameraerror.cameracaptureerror) and the recording is therefore cancelled.
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:::note
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Due to limitations of the React Native Bridge, this function can not be awaited. This means, any errors thrown while trying to start the recording (e.g. `capture/recording-in-progress`) can only be caught synchronously (`isBlockingSynchronousMethod`). This will change with the upcoming React Native Re-Architecture.
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:::
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To stop the video recording, you can call [`stopRecording(...)`](../api/classes/camera.camera-1#stoprecording):
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```ts
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await camera.current.stopRecording()
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```
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Once a recording has been stopped, the `onRecordingFinished` callback passed to the `startRecording` function will be invoked with a [`VideoFile`](../api/interfaces/videofile.videofile-1) which you can then use to display in a [`<Video>`](https://github.com/react-native-video/react-native-video) component.
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## Focussing
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To focus the camera to a specific point, simply use the Camera's [`focus(...)`](../api/classes/camera.camera-1#focus) function:
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```ts
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await camera.current.focus({ x: tapEvent.x, y: tapEvent.y })
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```
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The focus function expects a [`Point`](../api/interfaces/point.point-1) parameter which represents the location relative to the Camera View where you want to focus the Camera to. If you use react-native-gesture-handler, this will consist of the [`x`](https://docs.swmansion.com/react-native-gesture-handler/docs/api/gesture-handlers/tap-gh#x) and [`y`](https://docs.swmansion.com/react-native-gesture-handler/docs/api/gesture-handlers/tap-gh#y) properties of the tap event payload.
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So for example, `{ x: 0, y: 0 }` will focus to the upper left corner, while `{ x: CAM_WIDTH, y: CAM_HEIGHT }` will focus to the bottom right corner.
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Focussing adjusts auto-focus (AF) and auto-exposure (AE).
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<br />
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#### 🚀 Next section: [Frame Processors](frame-processors)
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