             # get the new sha1 hashes
             (cb) =>
                 @_exec
-                    command : "sha1sum *.png"
+                    command : "sha1sum *.png *.jpg"
                     bash    : true
                     path    : "#{@path}/#{tmp}"
                     cb      : (err, output) =>

                    console.log("tmp dir = ", tmp)
                    cb(err)
            (cb) =>
                args = ['-dBATCH', '-dNOPAUSE',
                               "-sDEVICE=png#{opts.device}",
                               "-sOutputFile=#{tmp}/%d.png",
                               "-r#{opts.resolution}",

                            else
                                p = @page(n)
                                p.sha1 = obj.sha1
                                p.url = result.url
                                changed_pages.push(n)
                                cb()
                async.mapSeries(sha1_changed, update, cb)
        ], (err) =>
            opts.cb?(err, changed_pages)
        )
