React Native - Image Resize¶

Install¶

npm install --save react-native-image-resizer
react-native link react-native-image-resizer

Note: on latest versions of React Native, you may have an error during the Gradle build on Android (com.android.dex.DexException: Multiple dex files define Landroid/support/v7/appcompat/R$anim). Run cd android && ./gradlew clean to fix this.

Usage¶

import ImageResizer from 'react-native-image-resizer';

let compressFormat = 'JPEG' // or 'PNG'
let quality = 80 // out of 100

ImageResizer.createResizedImage(imageUri, newWidth, newHeight, compressFormat, quality).then((resizedImageUri) => {
  // resizeImageUri is the URI of the new image that can now be displayed, uploaded...
}).catch((err) => {
  // Oops, something went wrong. Check that the filename is correct and
  // inspect err to get more details.
});

WARNING: On Android, file: will be prepended to the returned

string. This allows it to be displayed as an image, but it also means you won’t be able to access the file directly when using a utility like fs. To do so, you can simply use rawPath = originalPath.replace('file:', '') to get the raw path.

Option	Description
path	Path of image file, or a base64 encoded image string prefixed with ‘data:image/imagetype;base64,’ where imagetype is jpeg or png.
maxWidth	Image max width (ratio is preserved)
maxHeight	Image max height (ratio is preserved)
compressFormat	JPEG, PNG, or WEBP (Android only)
quality	A number between 0 and 100 used for JPEG compression
rotation	Rotation to apply to the image, in degrees, for android. On iOS, rotation is limited (and rounded) to multiples of 90 degrees.
outputPath	The resized image path. If null, resized image will be stored in cache folder. To set outputPath make sure to add option for rotation too (if no rotation is needed, just set it to 0).

Example¶

ImageResizer.createResizedImage(datauri, 640, 480, 'JPEG', 80).then((resizedImageUri) => {
    let i = new Izzati("http://192.168.1.17:5020/")
    i.send({text: {hello: 'me'}, file: {uri: resizedImageUri, filename: 'photo.jpg'}, response: {base64: false}}, (out) => {
        this.setState(previous => {
            return {uri: i.prefixPath(out.path)}
      })
    })
}).catch((err) => {
    console.log(err)
})