title: Passing System.Drawing.Common.Bitmap (.NET Standard 2.0) to class expecting System.Dwawing.Bitmap (.NET 4.7.2)
body: <p>I am wokring on converting some class libraries from .NET 4.7.2 over to .NET Standard (so that other Standard/Core assemblies can better use them), and I'm running into a problem with a particular third party library. This library performs image processing, and many of it's classes' methods take <code>Image</code> or <code>Bitmap</code> objects from the classic <code>System.Drawing</code> namespace.</p>
  
  <p>I have found the .NET Standard package <code>System.Drawing.Common</code> that has the compatibility classes in it, so that my own uses of those classes in my source code is working fine. But when I try to pass one of these classes into this library, I get an error:</p>
  
  <blockquote>
    <p>Reference to type 'Bitmap' claims it is defined in 'System.Drawing', but it could not be found </p>
  </blockquote>
  
  <p>I think I understand what's going on here (the types are defined in assemblies with different names, so they are different types). But is there any way to make these work as-is? Or will it require the vendor of the third-party library to make changes on their side to support .NET Standard?</p>