Simple json file upload in rails api

client.rb

#!/home/rahul/.rbenv/shims/ruby

require 'rest_client'
require 'base64'

image_data = Base64.encode64(File.open("/home/rahul/Pictures/download.jpg", "rb").read)

url = "http://myapiserver.com/api/user_profile/454-Rahul-Chaudhari?auth_token=XXXXXXXXXXXXXXX"
data = { user_profile: { picture: { content_type: "image/jpeg", filename: "DSCN436xxx0.JPG", data: image_data}}}
header = {content_type: "json", accept: "json", Authorization: "Token token=\"e4be11da6efca91461d4fd8fc5edb175\""}

RestClient.put( url, data, header)

UserProfile.rb

class UserProfile < ActiveRecord::Base
  has_attached_file :picture,
    styles: {
      original: {geometry: '1000x0>'},
      thumb: '100x100#',
      large: '300x200>',
    },
    convert_options: {large: "-quality 80 -strip -interlace Plane"},
    default_url: "http://s3-ap-southeast-1.amazonaws.com/#{ENV["S3_BUCKET"]}/user_profiles/placeholder.png",
    path: (Rails.env == 'test' || Rails.env == 'development') ? ":rails_root/public/images/:class/:id/:style/:filename" : "/:class/:id/:style/:filename",
    url: '/images/:class/:id/:style/:basename.:extension'

  validates_attachment_size :picture, less_than: 5.megabytes
  validates_attachment_content_type :picture, content_type: ['image/jpeg', 'image/png'], message: 'file type is not acceptable'
end

UserProfileController.rb

module Api
  module V1
    class UserProfileController < ApiController
      load_and_authorize_resource :user, parent: false

      def show
        @user_profile = @user.user_profile
        respond_with @user_profile, serializer: Api::V1::UserProfileSerializer
      end

      def update
        @user_profile = @user.user_profile
        if @user_profile.update(user_profile_params)
          render json: {success: true, profile: Api::V1::UserProfileSerializer.new(@user_profile)}, status: :ok
        else
          render json: {success: false, errors: @user_profile.errors}, status: :unprocessable_entity
        end
      end

      private
      def user_profile_params
        process_picture()
        params.require(:user_profile).permit( :first_name, :last_name, :picture)
      end

      def process_picture
        if params[:user_profile] && params[:user_profile][:picture]
          data = StringIO.new(Base64.decode64(params[:user_profile][:picture][:data]))
          data.class.class_eval { attr_accessor :original_filename, :content_type }
          data.original_filename = params[:user_profile][:picture][:filename]
          data.content_type = params[:user_profile][:picture][:content_type]
          params[:user_profile][:picture] = data
        end
      end
    end
  end
end