asciihex (PDF::Reader::Filter)

    # File lib/pdf/reader/filter.rb, line 82
        def asciihex(data)
          data.chop! if data[-1,1] == ">"
          data = data[1,data.size] if data[0,1] == "<"
          data.gsub!(/[^A-Fa-f0-9]/,"")
          data << "0" if data.size % 2 == 1
          data.scan(/.{2}/).map { |s| s.hex.chr }.join("")
        rescue Exception => e
          # Oops, there was a problem decoding the stream
          raise MalformedPDFError, "Error occured while decoding an ASCIIHex stream (#{e.class.to_s}: #{e.to_s})"
        end