Image not show in pdf (pdfkit)

I am using Carrierwave to upload images in rails4.

In the view page the uploaded image is showing. But, when generating the
from this view, the image is not showing.Instead , a blank box is
showing.from many from frorums i got a suggestion that use the absolute
url to display images in pdf

From the view, while inspecting the path is showing as below:

Small images

The code i used is:

<%=image_tag Student.find(id).image_url(:small) %>

Can u pls help…