title: Display Bitmap in gray scale of one color space component value only
body: <p>I would like to know how can I display color Bitmap in gray-scale. It must be done for each color space components separately. Probably it is not clear, therefore I uploaded images to visualize it: 
  <a href="http://imgur.com/T6gWZbD&amp;x0RrRU6&amp;ezpj8gV&amp;YSn0ylD#0" rel="nofollow">Grey-scale images visualisation</a>
  These Bitmaps are displayed after color conversion into one color space component: B, G, R, S (blue, green red, saturation). I want to repeat it in Android. I tried something like this:</p>
  
  <pre><code>case 'blue': pixels[i]=Color.argb(alpha,0,0,blue);
  </code></pre>
  
  <p>But it does not work at all. How to remove unnecessary components and present a Bitmap in gray-scale with a value of one color space component?</p>