insertingImageControl_RotatedImage2.cs

using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Media;
...
FileInfo imgInfo = new FileInfo(path_to_img)
  
// Create rotate transform that will be applied to our image.
RotateTransform transform = new RotateTransform(90); // 90-degree rotation transform.

// Control type
Image myImage = new Image();

BitmapImage bitmapImg = new BitmapImage();

// Create a Transformed Bitmap
TransformedBitmap bitmapImgTransform = new TransformedBitmap();

bitmapImg.BeginInit()
bitmap.UriSource = new Uri(imgInfo.FullName);
bitmap.EndInit();

// Setting the properties of our transformed bitmap.
bitmapImgTransform.BeginInit();
bitmapImgTransform.Source = bitmap;
bitmapImgTransform.Transform = transform; // Transform is applied through the 
bitmapImgTransform.EndInit();

myImage.Source = bitmapImgTransform; // Setting our image's source as the transformed bitmap.

// Create our BlockUIContainer
BlockUIContainer container = new BlockUIContainer();
container.Child = myImage;

// Insert container with image into the document.
FlowDocument doc = new FlowDocument();
doc.Blocks.Add(container);