title: AS3:How to change a colored Bitmap's BitmapData to black and white?
body: <p>How can I change the bitmapdata of a coloured Bitmap to <strong>Black and White</strong> in <strong>AS3</strong> ? 
  I'm developing a simple image editor tool for a CMS in flash. </p>
  
  <p>People should be able to switch the colour of the uploaded Bitmap to black and white. <strong>I want the bitmapdata itself to change</strong> So I can write it to a ByteArray with Adobe's JPGEncoder Class afterwards. </p>