redundant image when use with jquery upload Edit

I'm newbie in carrierwave, maybe i'm too hasty in doing that so correct me if i wrong
when i combine carrierwave with jquery file upload, i face a problem. Here is my case. 
I use jquery file upload in client to post create images event in rails and when user submit i attach these images to my object(like gallaries) but sometimes, user add images and they don't submit then these images already upload to server and become redundant. So I think we should upload to tmp folder and when user submit we handle in different action to move these images into correct folder. Here are my commit to fix that problem
```
class ImageUploader < CarrierWave::Uploader::Base
def store_dir
    "uploads/tmp/#{model.class.to_s.underscore}/#{model.id}"
  end

  def retrieve_dir
    "uploads/#{model.class.to_s.underscore}/#{model.id}"
  end
```
and in controller
```
class Gallaries
  def create
      \\move these images from tmp to correct folder in retrieve_dir
  end
```