I am creating a visualforce page that renders as pdf and I am trying to include an image but am running into an issue.  I have tried to store the image in the static resources, as well as in a document folder but neither option works. 

When I am logged in as the system admin the image appears on the PDF, but if I log in as any other user it appears broken. 

Below is the code on the visualforce page for image:

From Document library:

<center>
     <apex:image value="/servlet/servlet.FileDownload?file=015S000000Hz2u" width="262" height="50"/>
</center>

From Static Resources:

<center>
     <apex:image value="{!resources.logo}" width="262" height="50"/>
</center>

Any help would be great!