Bulk Import of User Pictures

Hello,

        I am am trying to complete a bulk import of pictures into our exchange. I have currently upgraded my environment from Exch 2007 to a clustered 2013 as well as upgraded to Lync 2013. I am using this cmd below to manualy import image by image but i have 500 end users and i would like to figure out how to complete this on a larger scale. Any help or Guidance is greatly appreciated.

Set-UserPhoto "John Doe" -PictureData ([System.IO.File]::ReadAllBytes("\\files\employeepcitures\JohnDoe.jpg"))

Thank you,

Peter