README.md

vision-camera-cropper

A react native vision camera frame processor for cropping

react-native-vision-camera-cropper.mp4

Versions

For Vision Camera v3, use versions 0.x.

For Vision Camera v4, use versions >= 1.0.0.

Installation

yarn add vision-camera-cropper
cd ios && pod install

Add the plugin to your babel.config.js:

module.exports = {
   plugins: [['react-native-worklets-core/plugin']],
    // ...

Note: You have to restart metro-bundler for changes in the babel.config.js file to take effect.

Usage

1. Crop a frame and return its base64 or path.

   import { crop } from 'vision-camera-cropper';
   
   // ...
   const frameProcessor = useFrameProcessor((frame) => {
     'worklet';
     //coordinates in percentage
     const cropRegion = {
       left:10,
       top:10,
       width:80,
       height:30
     }
     const result = crop(frame,{cropRegion:cropRegion,includeImageBase64:true,saveAsFile:false});
     console.log(result.base64);
   }, []);

2. Rotate an image.

   const rotated = await rotateImage(base64,degree);

Get Bitmap/UIImage via Reflection

If you are developing a plugin to get the camera frames, you can use reflection to get it as Bitmap or UIImage on the native side.

Java:

Class cls = Class.forName("com.visioncameracropper.CropperFrameProcessorPlugin");
Method m = cls.getMethod("getBitmap",null);
Bitmap bitmap = (Bitmap) m.invoke(null, null);

Objective-C:

- (UIImage*)getUIImage{
    UIImage *image = ((UIImage* (*)(id, SEL))objc_msgSend)(objc_getClass("CropperFrameProcessorPlugin"), sel_registerName("getBitmap"));
    return image;
}

You have to pass {saveBitmap: true} for the crop function.

Blog

How to Create a React Native Vision Camera Plugin to Crop Frames

Contributing

See the contributing guide to learn how to contribute to the repository and the development workflow.

License

MIT

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Made with create-react-native-library