react-native-vision-camera/docs/FRAME_PROCESSORS.md

README	DEVICES	FORMATS	FRAME_PROCESSORS	ANIMATED	ERRORS

Frame Processors

What are frame processors?

Frame processors are functions that are written in JavaScript (or TypeScript) which can be used to process frames the camera "sees".

For example, you might want to create a QR code scanner without ever writing native code while still achieving almost-native performance. Since you can write the scanning part yourself, you can implement a custom QR code system like the one Snapchat uses for Snap-codes.

Frame processors are by far not limited to QR code detection, other examples include:

• AI for facial recognition
• AI for object detection
• Using Tensorflow, MLKit Vision or other libraries (if they provide React Native JSI bindings in the form of "react-native-vision-camera plugins")
• Creating realtime video-chats since you can directly send the camera frames over the network
• Creating snapchat-like filters, e.g. draw a dog-mask filter over the user's face (WIP)
• Creating color filters with depth-detection
• Using custom C++ processors exposed to JS for maximum performance

Technical

Frame processors are JS functions that will be workletized using react-native-reanimated. They are created on a separate thread using a separate Hermes/JSC Runtime and are invoked synchronously (using JSI) without ever going over the bridge.

Example

function App() {
  const frameProcessor = useFrameProcessor((frame) => {
    const qrCodes = scanQrCodes(frame)
    console.log(qrCodes)
  }, [])

  return (
    <Camera frameProcessor={frameProcessor} {...cameraProps} />
  )
}

FRAME PROCESSORS ARE STILL WIP