title: Validate Image type for IFormFile in ASP.Net Core
body: <p>I have an ASP.NET Core application and I need to validate that the uploaded file is an image and not a non-image file which has an image extension....
  All solutions that I found and makes sense use System.Drawing.Image or similar classes that aren't available in ASP.NET Core.
  Can you kindly suggest an alternative?
  *Please note that I'm not trying to check the extension but the contents.</p>
  
  <p>Thank you</p>