How to retrieve the exif orientation value in flutter

Question

I am developing an app using Flutter and I want to retrieve the exif orientation value of an image that I selected using the image_picker plugin.

When I run the code below and select an image that I have rotated beforehand, I get null for the orientation value and an empty Map for the exif data.

File file = await ImagePicker.pickImage(
  source: ImageSource.gallery,
);
img.Image decodedImage = img.decodeImage(file.readAsBytesSync());
print("decodedImage.exif.orientation ${decodedImage.exif.orientation}"); // null
print("decodedImage.exif.data ${decodedImage.exif.data}"); // {}

I send the image that I used with this code to my mac book through google drive to see the orientation value and this is what I got:

I am using the newest available version of the image_picker plugin. How can I retrieve the exif orientation value of an image in Flutter?

Solution

I used this function:

  needRotation(String path) async {
    Map<String, IfdTag> data =
        await readExifFromBytes(await new File(path).readAsBytes());
    return data['EXIF ExifImageWidth'].values[0] >
        data['EXIF ExifImageLength'].values[0];
  }

using import 'package:exif/exif.dart';

Explain: given the path of an image it will return if need rotation (i.e. is in landscape mode)

I also hadthe null orientation problem that u mentioned and uses the width/height to figure it out my self...

It seems weired I know... hope someone comes with a better solution.