vision-camera-ocr-plugin

A VisionCamera Frame Processor Plugin to preform text detection on images using MLKit Vision Text Recognition. This module can be used only with React Native Vision Camera >= v4.x.x

Installation

``sh
yarn add vision-camera-ocr-plugin
cd ios && pod install
`

Add the plugin to your babel.config.js:

`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

`js
import {OCRFrame, scanOCR} from 'vision-camera-ocr-plugin';
import {
useFrameProcessor,
Camera,
useCameraDevice,
} from 'react-native-vision-camera';
import {Worklets} from 'react-native-worklets-core';

export default ({onTextClicked}: VisionCameraPlateProps) => {
const [hasPermission, setHasPermission] = React.useState(false);
const [ocr, setOcr] = React.useState();
const isFocused = useIsFocused();
const device = useCameraDevice('back');

const onCodeDetected = Worklets.createRunInJsFn((data: any) => {
setOcr(data);
});

const frameProcessor = useFrameProcessor(frame => {
'worklet';
const data = scanOCR(frame);
onCodeDetected(data);
}, []);

React.useEffect(() => {
(async () => {
const status = await Camera.requestCameraPermission();
setHasPermission(status === 'granted');
})();
}, []);


return (
<>
{device !== undefined && hasPermission ? (
frameProcessor={frameProcessor}
device={device}
isActive={isFocused}
pixelFormat="yuv"
/>
) : (

No available cameras

)}

);
};

`

Data

scanOCR(frame) returns an OCRFrame with the following data shape. See the example for how to use this in your app.

` jsx
OCRFrame = {
result: {
text: string, // Raw result text
blocks: Block[], // Each recognized element broken into blocks
;
};
`

The text object closely resembles the object documented in the MLKit documents.


`
The Text Recognizer segments text into blocks, lines, and elements. Roughly speaking:

a Block is a contiguous set of text lines, such as a paragraph or column,

a Line is a contiguous set of words on the same axis, and

an Element is a contiguous set of alphanumeric characters ("word") on the same axis in most Latin languages, or a character in others
``

Contributing

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

License

MIT