     r: zero new Array 256
     g: zero new Array 256
     b: zero new Array 256
+    a: zero new Array 256
     y: zero new Array 256
     h: zero new Array 361 # degrees [0,0, 360.0] -> [0, 361]
     s: zero new Array 101 # [0.0, 1.0] -> [0, 101]

  normalize res.r, pixels
  normalize res.g, pixels
  normalize res.b, pixels
  normalize res.y, pixels
  normalize res.h, pixels
  normalize res.s, pixels

  imageData = ctx.getImageData 0, 0, canvas.width, canvas.height
  data = imageData.data
  for i in [0...data.length] by 4
    [r, g, b, a] = [data[i], data[i+1], data[i+2], data[i+3]]
    y = cie_y601 r/255, g/255, b/255
    y = Math.floor y*255
    res.r[r]+=1
    res.g[g]+=1
    res.b[b]+=1
    res.a[a]+=1
    res.y[y]+=1

    rgb = chroma(r, g, b, 'rgb')
