Retrieving images stored in mongodb

I have tried to retrieve images I uploaded and saved to mongodb but I am not able to retrieve back the image directly from db. There seems to be a lot of information about uploading files but not a lot of information about retrieving the uploaded images from the db.

I would really appreciate your help. Thanks in advance.

This is part of what is saved in mongodb:

{
    "_id": {
        "$oid": "58e9aba1cc06152fd0d3bc56"
    },
    "img": {
        "data": "<Binary Data>",
        "contentType": "image/png"
    }
}

Schema:

var mongoose = require('mongoose');

var ImageSchema = new mongoose.Schema({
  img: { data: Buffer, contentType: String }
});

module.exports = mongoose.model('Image', ImageSchema);

router.js

router.post('/blog/article/addPost', upload.single('image'), function(req, res, err) {
      var image = new Image ({
        img: {
          data: req.file.filename,
          contentType: 'image/png'
        }
      });
    image.save(function(err, image) {
          //other code
        });
});

Part of ejs to upload file

<form action="/blog/article/addPost" method="post" enctype="multipart/form-data">
        <div class="form-group">
          <label="name">Add a picture for your article</label>
          <input id="upload-input" type="file" class="form-control" name="image"/>
        </div>
</form>

ejs to retrieve file:

<div class="col-md-4">
        <form method="GET" action="/blog/article/<%= image.id %>">
          <img src="<%= image.img %>" style="width:304px;height:228px;">
        </form>
</div>

via CODI