iOS: Get displayed image size in pixels : <p>In my app, I'm displaying an image of a rectangle from the assets library.  The image is 100x100 pixels.  I'm only using the 1x slot for this asset.</p>

<p>I want to display this image at 300x300 pixels.  Doing this using points is quite simple but I can't figure out how to get UIImageView to set the size in pixels.</p>

<p>Alternatively, if I can't set the size in pixels to display, I'd like to get the size in pixels that the image is being displayed.</p>

<p>I have tried using <code>.scale</code> on the UIImageView and UIImage instances, but it's always 1.  Even though I have set constraints to 150 and 300.</p>
