A way to crop an image from an image stream in flutter to always have a 4:3 aspect ratio

resize.dart

// For FlutterNativeImage, see: https://github.com/btastic/flutter_native_image

// Takes the absolute file path
Future<String> resizeImage(String filePath) async {
    ImageProperties properties = await FlutterNativeImage.getImageProperties(filePath);

    int imageWidth;
    int imageHeight;
    switch (properties.orientation) {
      case ImageOrientation.rotate90:
      case ImageOrientation.rotate270:
        imageWidth = properties.height;
        imageHeight = properties.width;
        break;
      default:
        imageWidth = properties.width;
        imageHeight = properties.height;
    }

    int aspectHeight = ((imageWidth / 3) * 4).round();
    // Make sure cropping is required and possible
    if (aspectHeight >= imageHeight) {
      return filePath;
    }
    double offset = (imageHeight - aspectHeight) / 2;
   
    File croppedFile;
    switch (properties.orientation) {
      case ImageOrientation.rotate90:
      case ImageOrientation.rotate270:
        croppedFile = await FlutterNativeImage.cropImage(
          filePath, offset.round(), 0, aspectHeight, imageWidth);
        break;
      default:
        croppedFile = await FlutterNativeImage.cropImage(
          filePath, 0, offset.round(), imageWidth, aspectHeight);
    }

    return croppedFile.path;
}