title: Initialize image in django admin add form from another model image
body: <p>I have a model,</p>
  
  <pre><code>class Abc(models.Model):
      .
      .
      pic = models.ImageField(upload_to = path,default = 'images/nophoto.jpg')
      .
      .
  </code></pre>
  
  <p>And in admin list view for this model, have an Add button column which will load add form of another model admin (Xyz) which also have an image field. What I want is to initialize image in Xyz add form with image in selected Abc instance.</p>
  
  <p>I have tried </p>
  
  <pre><code>def add_view(self, request, form_url='', extra_context=None):
          .
          .
      g = request.GET.copy()
      g.update({
          'image': abc_instance.image,
       })
      request.GET = g
          .
          .
  </code></pre>
  
  <p>In Xyz admin, and it shows image in form but on saving image is not getting saved. </p>
  
  <p>What can I do to accomplish this?</p>