# rn-ocr-lib React native library to perform OCR on images. This library uses Tesseract library for image processing in android and vision library for iOS. [![Npm package version](https://badgen.net/npm/v/rn-ocr-lib)](https://npmjs.com/package/rn-ocr-lib) [![Npm package monthly downloads](https://badgen.net/npm/dm/rn-ocr-lib)](https://npmjs.com/package/rn-ocr-lib) [![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://opensource.org/licenses/MIT) ![React Native](https://img.shields.io/badge/react_native-%2320232a.svg?style=for-the-badge&logo=react&logoColor=%2361DAFB) ![Android](https://img.shields.io/badge/Android-3DDC84?style=for-the-badge&logo=android&logoColor=white) ![iOS](https://img.shields.io/badge/iOS-000000?style=for-the-badge&logo=ios&logoColor=white) ## Showcase Demo ## Installation ```sh npm install rn-ocr-lib # or yarn add rn-ocr-lib ``` ## Setup ### Android Create folder `app/src/main/assets/tessdata`. Inside `tessdata` place `${lang}.traineddata`. You can get the train data files from [here](https://tesseract-ocr.github.io/tessdoc/Data-Files.html). ### iOS Vision library is present in iOS from version 13 or above. So update `ios/Podfile`. ```ruby platform :ios, '13.0' ``` ## Usage Kindly refer the [example](example/) project for usage for Android and iOS. ## API Reference ### Methods ```javascript import { getText, useOCREventListener } from 'rn-ocr-lib'; ``` **getText** Call this method to initiate image processing ```typescript getText(data: string, dataInputType: DataInputType, options?: Partial): void; ``` **useOCREventListener** Call this hook to setup listener to listen to progress, result and error. ```typescript useOCREventListener( (event: OCREventType, ocrEventResponse: OCREventResponse) => { switch (event) { case OCREvent.FINISHED: return; case OCREvent.PROGRESS: return; case OCREvent.ERROR: return; default: return; } } ); ``` ### Parameters **dataInputType** | Input type | Value | Description | | ---------- | ------ | ------------------ | | file | FILE | Path to image file | | base64 | BASE64 | Base64 string | \ **options** | Option | Type | iOS | Android | Default | Description | | ------------- | ------------- | --- | ------- | ------------ | --------------------------------------------------- | | ocrEngineMode | OCREngineMode | Yes | Yes | FAST | Type of mode between fast or accurate recognization | | pageSegMode | PageSegMode | No | Yes | PSM_OSD_ONLY | Page seg mode of tesseract | | lang | string[] | Yes | Yes | ["eng"] | Languages for which recognization is needed | \ **ocrEngineMode** | Engine Mode | Value | Description | | ------------- | ----- | ----------------------------------------------------------------------------------------------------------------------------------------------------- | | FAST | 0 | Fast mode where recognization will be faster but mismatch of words is possible | | ACCURATE | 1 | Accurate mode where time to process is more but more accurate text will be obtained | | FAST_ACCURATE | 2 | Relavant for android tesseract where train data is provided for accurate and fast results but traindata file may be bigger compared to previous modes | \ **pageSegMode (Android)** By default Tesseract expects a page of text when it segments an image. If you’re just seeking to OCR a small region, try a different segmentation mode. | Segmentation Mode | Value | Description | | -------------------------- | ----- | --------------------------------------------------------------------------------------------- | | PSM_OSD_ONLY | 0 | Orientation and script detection (OSD) only. | | PSM_AUTO_OSD | 1 | Automatic page segmentation with OSD. | | PSM_AUTO_ONLY | 2 | Automatic page segmentation, but no OSD, or OCR. | | PSM_AUTO | 3 | Fully automatic page segmentation, but no OSD. (Default) | | PSM_SINGLE_COLUMN | 4 | Assume a single column of text of variable sizes. | | PSM_SINGLE_BLOCK_VERT_TEXT | 5 | Assume a single uniform block of vertically aligned text. | | PSM_SINGLE_BLOCK | 6 | Assume a single uniform block of text. | | PSM_SINGLE_LINE | 7 | Treat the image as a single text line. | | PSM_SINGLE_WORD | 8 | Treat the image as a single word. | | PSM_CIRCLE_WORD | 9 | Treat the image as a single word in a circle. | | PSM_SINGLE_CHAR | 10 | Treat the image as a single character. | | PSM_SPARSE_TEXT | 11 | Sparse text. Find as much text as possible in no particular order. | | PSM_SPARSE_TEXT_OSD | 12 | Sparse text with OSD. | | PSM_RAW_LINE | 13 | Raw line. Treat the image as a single text line, bypassing hacks that are Tesseract-specific. | \ **event** | Event type | Value | Description | | ---------- | -------- | ---------------------------------------------------- | | FINISHED | finished | Event when OCR completes | | PROGRESS | progress | Progress event when OCR is processing | | ERROR | error | Error event OCR fails and some error is being thrown | \ **ocrEventResponse** | Key | Type | Description | | -------- | ------ | ---------------- | | text | string | Result text | | progress | number | Progress percent | | error | string | Error message | ## Language Support ### Android [Here](https://tesseract-ocr.github.io/tessdoc/Data-Files-in-different-versions.html) is the list of supported languages for android. ### iOS Vision library currently has limited language support. It supports the following languages. | Language | Code | | ------------------- | ------- | | English | eng | | France | fra | | Italian | ita | | German | deu | | Spanish | spa | | Portuguese | por | | Chinese Simplified | chi_sim | | Chinese Traditional | chi_tra | ## Contributing See the [contributing guide](CONTRIBUTING.md) to learn how to contribute to the repository and the development workflow. ## License MIT --- Made with [create-react-native-library](https://github.com/callstack/react-native-builder-bob)