@infinitered/react-native-mlkit-core

Description

This is a shared library for RNMLKit that contains helper functions and shared code for various packages. It offers some helpful methods that are used by many apps on the React Native (JS) side and includes functionality to work with images and bounding boxes.

Installation

Use the following command to install the package:

npm install @infinitered/react-native-mlkit-core

Usage

RNMLKitImage

Swift

Use this class in Swift to create and manage images with MLKitVision. It provides utility methods for loading images and managing their vision representations.

import RNMLKitCore
let image = RNMLKitImage(imagePath: imagePath)
// ...

• imagePath - should be the localUri of the image to process. i.e. Asset.localUri from an Expo Asset or Image.uri from an ImagePickerAsset.

Kotlin

Use this class in Kotlin to create and manage images with MLKitVision. It provides utility methods for loading images and managing their vision representations.

import com.infinitered.reactnativemlkitcore.RNMLKitImage

val imageUri = Uri.parse(imagePath)
var image:InputImage = RNMLKitImage(imagePath, appContext.reactContext!!).image
// ...

• imagePath is the localUri of the image to process. Asset.localUri from an Expo Asset or Image.uri from an Expo ImagePickerAsset.
• appContext is the AppContext from your expo module -- it's accessible as a property on the Module class.

React Components

BoundingBoxView

Renders a bounding box based on the specified dimensions and scale.

import { BoundingBoxView } from "@infinitered/react-native-mlkit-core";
// ...
<BoundingBoxView box={box} scale={scale} />;

• box is the bounding box to render of type BoundingBox

/**
 * Represents a bounding box with origin, size, color, label, and width properties.
 */
export interface BoundingBox {
  origin: { x: number; y: number };
  size: { x: number; y: number };
  color?: string;
  label?: string;
  width?: number;
}

ImageWithBoundingBoxes

Renders an image with bounding boxes drawn over specified regions.

import { ImageWithBoundingBoxes } from "@infinitered/react-native-mlkit-core";
// ...
<ImageWithBoundingBoxes image={image} boundingBoxes={boundingBoxes} />;

• boundingBoxes is an array of BoundingBox objects to render over the image.
• image is the image to render. Accepts an Image from expo-image

Hooks

Several hooks are included to assist with layout and scaling:

• useBoundingBoxStyle: Calculates the style object for a bounding box.
• useImageScale: Calculates the image scale based on the provided parameters.
• useLayout: Handles layout change events.