Create blank image in Imagemagick : <p>How to create a blank new image in Imagemagick via command line?</p>

<p>Using <code>-background</code> doesn't work:</p>

<pre><code>$ convert -size 800x800 -background white x.png
convert: no images defined `x.png' @ error/convert.c/ConvertImageCommand/3257.
</code></pre>
