undefined method `image' in my view

I am using Paperclip, and my only problem is that in my image tag, I have an undefined method "image".

<%= image_tag @posts.image.url(:medium) %>

is where my error is occurring. When I loaded a new migration, I accidentally did "rails g paperclip user image" instead of "rails g paperclip posts image" so I went into my code and changed "user" to "posts." I asked something similar and someone mentioned that it was with my schema.rb file(?).

Just to be safe, this is my post_params:

private
    def post_params
        params.require(:post).permit(:title, :body, :image)
    end

but here is my migration file:

class AddAttachmentImageToUsers < ActiveRecord::Migration
  def self.up
    change_table :posts do |t|
      t.attachment :image
    end
  end

  def self.down
    remove_attachment :posts, :image
  end
end