sagawrr/react-native-nitro-vision-kit

Features

removeBackground Subject cutout — trim, export PNG/JPEG, optional mask classifyImage Ranked labels — offline on both platforms readText OCR — Latin / CJK / Devanagari on Android; Vision on iOS 18+ analyzeImage All three from a single decode Cutout and OCR results live on the native side until you export them. Call dispose() when done.

Install

npm install react-native-nitro-vision-kit react-native-nitro-modules
cd ios && pod install

	Minimum
React Native	0.75
react-native-nitro-modules	0.36.0
iOS	13 · cutouts 17+ · OCR 18+
Android	API 24

Requires the New Architecture.

Usage

import { VisionKit } from 'react-native-nitro-vision-kit'

Cutout:

if (!VisionKit.capabilities.supportsBackgroundRemoval) {
  throw new Error(VisionKit.capabilities.backgroundRemovalUnavailableReason)
}

const cutout = await VisionKit.removeBackground(imagePath, { trim: true })
const path = await cutout.saveToTemporaryFile('png', 100)
cutout.dispose()

Labels:

const labels = await VisionKit.classifyImage(imagePath, {
  maxResults: 5,
  minConfidence: 0.5,
})

OCR:

const ocr = await VisionKit.readText(imagePath)
console.log(ocr.text)
ocr.dispose()

All three at once:

const result = await VisionKit.analyzeImage(imagePath, {
  removeBackground: { trim: true },
  classify: { maxResults: 5 },
  readText: {},
})

result.segmentation?.dispose()
result.text?.dispose()

API

Capabilities

VisionKit.capabilities

Field	Meaning
supportsBackgroundRemoval	Cutouts available
backgroundRemovalUnavailableReason	Why not
supportsImageClassification	Labels available
supportsTextRecognition	OCR available
supportedTextLanguages	Language tags you can request

removeBackground(path, options?)

Returns a cutout HybridObject. iOS 17+, Android API 24+ with Play Services (ML Kit subject segmentation, beta).

Export via saveToTemporaryFile(format, quality), toArrayBuffer(), or toMaskBuffer().

Options & result fields

Option	Default	Meaning
trim	true	Crop to the subject
maxPixels	6_000_000	Cap when loading the image
retainMask	false	Keep mask for toMaskBuffer()

Result: width, height, bounds (VisionRect, 0–1), pixelBounds, foregroundCoverage, centroid, instanceCount, hasMask, sourceWidth, sourceHeight, trimOrigin.

classifyImage(path, options?)

Returns { label, confidence, index }[], highest confidence first. iOS 13+; on Android the model ships with the library.

Options

Option	Default	Meaning
maxResults	0	0 keeps all above the score floor
minConfidence	0.5	Lowest score to keep
region	full image	VisionRect (0–1)

readText(path, options?)

Returns a text HybridObject. Prefer text and blockAt(i) — blocks copies everything into JS. iOS 18+ (RecognizeTextRequest); Android uses Play Services script models (Latin, Chinese, Japanese, Korean, Devanagari).

Image load cap: 4M pixels on both platforms; on Android the longest side is also capped at 2048.

Options & platform quirks

Option	Default	Platform
languages	auto / Latin	Both
recognitionLevel	accurate	iOS
region	full image	Both (VisionRect)
minTextHeightFraction	unset	Both
usesLanguageCorrection	true	iOS
customWords	unset	iOS
maxCandidates	1	iOS (1–10)

Android: languages selects script models. Non-Latin models also read Latin; multiple non-Latin scripts can run together. A block may contain many lines.

iOS: each block is one line.

analyzeImage(path, options)

One decode. Pass at least one of removeBackground, classify, or readText.

• No subject found → segmentation omitted; labels and text still run.
• If classify/OCR omit region and a cutout ran → subject bounds are used.

Platform notes

Model download (Android)

classifyImage works offline out of the box (model is packaged). removeBackground and readText download a Play Services model once — allow up to ~2 minutes online on first use; offline with no model fails immediately. iOS ships its models with the OS.

Paths

Absolute paths and file:// work everywhere. content:// is Android-only.

Only pass paths created by your app — native code opens the path and returns pixels/text to JavaScript.

Example

cd example
npm install
cd ios && bundle install && bundle exec pod install && cd ..
npm run ios    # or: npm run android

After a cutout, Keep saves to Photos.

License

MIT · Security · Changelog