Class ImagePlacement

public sealed class ImagePlacement

// Open document
Document doc = new Document(@"D:\Tests\input.pdf");

// Create ImagePlacementAbsorber object to perform image placement search
ImagePlacementAbsorber abs = new ImagePlacementAbsorber();

// Accept the absorber for first page
doc.Pages[1].Accept(abs);

// Retrieve images with visible dimensions
foreach (ImagePlacement imagePlacement in abs.ImagePlacements)
{
    Bitmap scaledImage;
    using (MemoryStream imageStream = new MemoryStream())
    {
        // Retrieve image from resources
        imagePlacement.Image.Save(imageStream, ImageFormat.Png);
        Bitmap resourceImage = (Bitmap) Bitmap.FromStream(imageStream);
        // Create new bitmap with actual dimensions
        scaledImage = new Bitmap(resourceImage, (int)imagePlacement.Rectangle.Width, (int)imagePlacement.Rectangle.Height);
    }
}