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react-native-document-scanner

Demo gif

React Native Document Scanner (iOS only)

Live document detection library. Returns either a URI or a base64 encoded string of the captured image, allowing you to easily store it or use it as you wish !

Features :

  • Live detection
  • Perspective correction and crop of the image
  • Live camera filters (brightness, saturation, contrast)
  • Flash
  • Easy to use base64 image

#### Can be easily plugged with react-native-perspective-image-cropper

Demo crop gif

Getting started

Use version >=1.4.1 if you are using react-native 0.48+

$ npm install react-native-document-scanner --save

$ react-native link react-native-document-scanner

Edit the info.plist file in XCode and add the following permission : NSCameraUsageDescription

Remember, this library uses your device camera, you can't run it on a simulator.

With Cocoapods

If you want to use Cocoapods insteads of react-native link, add the following to your Podfile

  pod 'RNPdfScanner', :path => '../node_modules/react-native-document-scanner/ios'

Usage

import React,{ Component } from 'react';
import { View, Image } from 'react-native';
 
import DocumentScanner from 'react-native-document-scanner';
 
class YourComponent extends Component {
  render() {
    return (
      <View>
        <DocumentScanner
          useBase64
          onPictureTaken={data => this.setState({
            image: data.croppedImage,
            initialImage: data.initialImage,
            rectangleCoordinates: data.rectangleCoordinates,
          })}
          overlayColor="rgba(255,130,0, 0.7)"
          enableTorch={false}
          brightness={0.3}
          saturation={1}
          contrast={1.1}
          quality={0.5}
          onRectangleDetect={({ stableCounter, lastDetectionType }) => this.setState({ stableCounter, lastDetectionType })}
          detectionCountBeforeCapture={5}
          detectionRefreshRateInMS={50}
        />
        <Image source={{ uri: `data:image/jpeg;base64,${this.state.image}`}} resizeMode="contain" />
      </View>
    );
  }
}
 

Properties

Prop Default Type Description
overlayColor none string Color of the detected rectangle : rgba recommended
detectionCountBeforeCapture 5 integer Number of correct rectangle to detect before capture
detectionRefreshRateInMS 50 integer Time between two rectangle detection attempt
enableTorch false bool Allows to active or deactivate flash during document detection
useFrontCam false bool Allows you to switch between front and back camera
brightness 0 float Increase or decrease camera brightness. Normal as default.
saturation 1 float Increase or decrease camera saturation. Set 0 for black & white
contrast 1 float Increase or decrease camera contrast. Normal as default
quality 0.8 float Image compression. Reduces both image size and quality
useBase64 false bool If base64 representation should be passed instead of image uri's
captureMultiple false bool Keeps the scanner on after a successful capture

Manual capture

  • First get component ref
<DocumentScanner ref={(ref) => this.scanner = ref} />
  • Then call :
this.scanner.capture();

Each rectangle detection

Props Params Type Description
onRectangleDetect { stableCounter, lastDetectionType } object See below

The returned object includes the following keys :

  • stableCounter

Number of correctly formated rectangle found (this number triggers capture once it goes above detectionCountBeforeCapture)

  • lastDetectionType

Enum (0, 1 or 2) corresponding to the type of rectangle found 0. Correctly formated rectangle

  1. Wrong perspective, bad angle
  2. Too far

Returned image

Prop Params Type Description
onPictureTaken data object Returns the captured image in an object { croppedImage: ('URI or BASE64 string'), initialImage: 'URI or BASE64 string', rectangleCoordinates: 'object of coordinates' }

If you prefer manual installation

  1. In XCode, in the project navigator, right click LibrariesAdd Files to [your project's name]
  2. Go to node_modulesreact-native-pdf-scanner and add RNPdfScanner.xcodeproj
  3. In XCode, in the project navigator, select your project. Add libRNPdfScanner.a to your project's Build PhasesLink Binary With Libraries
  4. Run your project (Cmd+R)<

Credits

This repo is a React Native implementation of the following native library : https://github.com/mmackh/IPDFCameraViewController Special thank to Mark Peysale :)