 
   initialize: (attrs, options) ->
     super(attrs, options)
-    @palette       = @_build_palette(@get('palette'))
-    @little_endian = @_is_little_endian()
+    @_palette       = @_build_palette(@get('palette'))
+    @_little_endian = @_is_little_endian()
     if @get('reserve_color')?
-      @reserve_color = parseInt(@get('reserve_color').slice(1), 16)
-      @reserve_val   = @get('reserve_val')
+      @_reserve_color = parseInt(@get('reserve_color').slice(1), 16)
+      @_reserve_val   = @get('reserve_val')
 
   v_map_screen: (data) ->
     buf = new ArrayBuffer(data.length * 4)

    else
      for i in [0...data.length]
        d = data[i]
        if (d == @reserve_val)
          value = @reserve_color
        else
          if (d > high)
            d = high
          if (d < low)
            d = low
          value = @palette[Math.floor(d*scale+offset)] # rgb

        color[i] = (value << 8) | 0xff               # alpha


    low = @get('low') ? _.min(data)
    high = @get('high') ? _.max(data)

    N = @_palette.length - 1
    scale = N/(high-low)
    offset = -scale*low

    if @_little_endian
      for i in [0...data.length]
        d = data[i]

        if (d == @_reserve_val)
          value = @_reserve_color
        else
          if (d > high)
            d = high
          if (d < low)
            d = low
          value = @_palette[Math.floor(d*scale+offset)]

        color[i] =
          (0xff << 24)               | # alpha
