Django: Display image in admin interface

UPDATE 2020

Because this answer is getting a lot of traction recently, I decided to make small edit. According to django doc it is recommended to use function format_html. As @chem1st suggested, if you need it only for admin, everything can be made in admin.py only.

My models.py

from django.db import models

class Product(models.Model):
    title = models.CharField(max_length=120)
    description = models.TextField()
    price = models.DecimalField(decimal_places = 2, max_digits = 20, default = 00.00)
    image = models.ImageField(upload_to=change_image_name, null=True, blank=True)

    def __str__(self):
        return self.title

My admin.py

from django.contrib import admin
from django.utils.html import format_html

from .models import Product

class ProductAdmin(admin.ModelAdmin):
    list_display = ('title', 'description', 'price', 'image_tag')

    def image_tag(self,obj):
        return format_html('<img src="{0}" style="width: 45px; height:45px;" />'.format(obj.image.url))

admin.site.register(Product, ProductAdmin)

UPDATE django 2.0.6

I was solving this problem in latest django 2.0.6. I wanted have an image thumbnail in a list view in the django-admin.

Picture below is my default admin listview.

This is my models.py:

from django.db import models
from django.utils.safestring import mark_safe

# Create your models here.

class Product(models.Model):
    title = models.CharField(max_length=120)
    description = models.TextField()
    price = models.DecimalField(decimal_places = 2, max_digits = 20, default = 00.00)
    image = models.ImageField(upload_to=change_image_name, null=True, blank=True)

    def image_tag(self):
        if self.image:
            return mark_safe('<img src="%s" style="width: 45px; height:45px;" />' % self.image.url)
        else:
            return 'No Image Found'
    image_tag.short_description = 'Image'
    

    def __str__(self):
        return self.title

Please notice I had to use mark_safe() on the image string, otherwise you will get escaped html code instead of a thumbnail in the django-admin

Finally, this is my admin.py

from django.contrib import admin

from .models import Product
# Register your models here.
class ProductAdmin(admin.ModelAdmin):
    list_display = ('title', 'description', 'price', 'image_tag')

admin.site.register(Product, ProductAdmin)

Here we have to register the ProductAdmin class too, I didn't know that and it didn't work.

This is result:

You can create a model instance method with another name, allow HTML tags for its output and add this method as a list field. Here is an example:

First add a new method returning the HTML for the image inclusion:

class Article(models.Model):
    ...
    def admin_image(self):
        return '<img src="%s"/>' % self.img
    admin_image.allow_tags = True

Then add this method to the list:

class ArticleAdmin(admin.ModelAdmin):    
    ...
    list_display = ('url', 'title', 'admin_image')