iOS UIImagePickerController result image orientation after upload

Question

I am testing my iPhone application on an iOS 3.1.3 iPhone. I am selecting/capturing an image using a UIImagePickerController:

UIImagePickerCont         


        

Answer 1

I transposed this into Xamarin:

private static UIImage FixImageOrientation(UIImage image)
    {
        if (image.Orientation == UIImageOrientation.Up)
        {
            return image;
        }

        var transform = CGAffineTransform.MakeIdentity();

        float pi = (float)Math.PI;

        switch (image.Orientation)
        {
            case UIImageOrientation.Down:
            case UIImageOrientation.DownMirrored:
                transform = CGAffineTransform.Translate(transform, image.Size.Width, image.Size.Height);
                transform = CGAffineTransform.Rotate(transform, pi);
                break;

            case UIImageOrientation.Left:
            case UIImageOrientation.LeftMirrored:
                transform = CGAffineTransform.Translate(transform, image.Size.Width, 0);
                transform = CGAffineTransform.Rotate(transform, pi / 2);
                break;

            case UIImageOrientation.Right:
            case UIImageOrientation.RightMirrored:
                transform = CGAffineTransform.Translate(transform, 0, image.Size.Height);
                transform = CGAffineTransform.Rotate(transform, -(pi / 2));
                break;
        }

        switch (image.Orientation)
        {
            case UIImageOrientation.UpMirrored:
            case UIImageOrientation.DownMirrored:
                transform = CGAffineTransform.Translate(transform, image.Size.Width, 0);
                transform = CGAffineTransform.Scale(transform, -1, 1);
                break;

            case UIImageOrientation.LeftMirrored:
            case UIImageOrientation.RightMirrored:
                transform = CGAffineTransform.Translate(transform, image.Size.Height, 0);
                transform = CGAffineTransform.Scale(transform, -1, 1);
                break;
        }

        var ctx = new CGBitmapContext(null, (nint)image.Size.Width, (nint)image.Size.Height, image.CGImage.BitsPerComponent,
            image.CGImage.BytesPerRow, image.CGImage.ColorSpace, image.CGImage.BitmapInfo);

        ctx.ConcatCTM(transform);

        switch (image.Orientation)
        {
            case UIImageOrientation.Left:
            case UIImageOrientation.LeftMirrored:
            case UIImageOrientation.Right:
            case UIImageOrientation.RightMirrored:
                ctx.DrawImage(new CGRect(0, 0, image.Size.Height, image.Size.Width), image.CGImage);
                break;

            default:
                ctx.DrawImage(new CGRect(0, 0, image.Size.Width, image.Size.Height), image.CGImage);
                break;
        }

        var cgimg = ctx.ToImage();
        var img = new UIImage(cgimg);

        ctx.Dispose();
        ctx = null;
        cgimg.Dispose();
        cgimg = null;

        return img;
    }