[Bug] Xamarin Android can't read EXIF data from the rotated image to check whether the image rotated or not

[jeyakasipandi]

Description

To check whether the image is rotated or not by reading the EXIF meta data based on the orientation rotate then create the new bitmap and set to ImageView control.

[C#]

    protected override void OnCreate(Bundle savedInstanceState)
        {
            base.OnCreate(savedInstanceState);
            Xamarin.Essentials.Platform.Init(this, savedInstanceState);
            ImageView image = new ImageView(this);
            var bitmap = BitmapFactory.DecodeResource(Resources, Resource.Drawable.test);
            ExifInterface originalMetadata;
            using (var stream = new MemoryStream())
            {
                bitmap.Compress(Bitmap.CompressFormat.Jpeg, 0, stream);
                originalMetadata = new ExifInterface(stream);
            }

            int orientation = GetRotation(originalMetadata);

            Matrix matrix = new Matrix();
            if (orientation != 0)
            {
                matrix.PreRotate(orientation);
                bitmap = Bitmap.CreateBitmap(bitmap, 0, 0, bitmap.Width, bitmap.Height, matrix, true);
            }
            image.SetImageBitmap(bitmap);

            // Set our view from the "main" layout resource
            SetContentView(Resource.Layout.activity_main);
        }

Expected Behavior

To read the rotated image ExifData to get the orientation. Based on the orientation rotate then create the new bitmap and set to ImageView control.

Actual Behavior

Getting the ExifData orientation value as 0.

Basic Information

Tested device are Huawei PRA, Infinix Pro

Environment

Visual Studio 2019

Screenshots

[![enter image description here][1]][1]

Sample Link

ImageDemo.zip

Uploading Image_CameraAndGallery.zip…

[jpobst]

I the core issue is that Android's BitmapFactory does not respect EXIF data:
https://stackoverflow.com/questions/45552108/is-it-possible-to-make-bitmapfactory-decodefile-respect-exif

Thus when you try to save the Bitmap you received from it the EXIF data is already lost, so it's not in the JPEG you create.

You will need to either find a way to get a direct stream or path to the resource so you can pass it to new ExifInterface (...), or since these are resource files you may find it easier to just actually rotate your resource image files so they no longer rely on EXIF data for rotation.