title: Imagick center text over image in specified area
body: <p>I am using Imagick library to add text over image.
  I have defined area over image <code>from x:280 to x:400</code> 
  i am writing text in that area and i want to align that text in center the following code in centering text x:1 and x:400</p>
  
  <pre><code>$draw = new ImagickDraw();
  $draw-&gt;setFillColor('white');
  $draw-&gt;setFont($tffFile);
  
  $draw-&gt;setTextAlignment(Imagick::ALIGN_CENTER);
  $draw-&gt;setFontSize( 14 );
  $image-&gt;annotateImage($draw, 280, 80, 0, 'Hey there');
  </code></pre>