title: how to get setScaleType(ImageView.ScaleType.FIT_CENTER) effect using setScaleType(ImageView.ScaleType.MATRIX)
body: <p>In Android using ImageView and Matrix, I want to scale an image to fit in the display area.
  Then using pinch, a user can zoom the image.
  Using <code>setScaleType(ImageView.ScaleType.FIT_CENTER)</code> I can fit my image in display area. But when I use <code>setScaleType(ImageView.ScaleType.MATRIX)</code>, to start zooming the image, the image gets reset to default size.</p>
  
  <p>So my question is how to find a scale matrix which will give same effect as 
  <code>setScaleType(ImageView.ScaleType.FIT_CENTER)</code>.</p>