Description:
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It would be nice if identifyImage() can return the mime type.

Currently, it does not do that, so, I need to save the image to a temporary place and run getimagesize() on it, which is part of GD.

Test script:
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<?php 
$img = new Imagick('https://www.google.com.au/images/srpr/logo4w.png');
var_dump($img->identifyImage());

Expected result:
----------------
array (size=7)
  'format' => string 'PNG (Portable Network Graphics)' (length=31)
  'geometry' => 
    array (size=2)
      'width' => int 550
      'height' => int 190
  'units' => string 'Undefined' (length=9)
  'type' => string 'Palette' (length=7)
  'colorSpace' => string 'sRGB' (length=4)
  'compression' => string 'Zip' (length=3)
  'fileSize' => string '18.9KB' (length=6)
  'mimeType' => 'image/png'

Actual result:
--------------
array (size=7)
  'format' => string 'PNG (Portable Network Graphics)' (length=31)
  'geometry' => 
    array (size=2)
      'width' => int 550
      'height' => int 190
  'units' => string 'Undefined' (length=9)
  'type' => string 'Palette' (length=7)
  'colorSpace' => string 'sRGB' (length=4)
  'compression' => string 'Zip' (length=3)
  'fileSize' => string '18.9KB' (length=6)