This is a continuation of the previous article "Finite Field Arithmetic and Reed-Solomon Coding"[1]<p>[1]: <a href="http://research.swtch.com/field" rel="nofollow">http://research.swtch.com/field</a>
Regarding the portrait used in many of the example QR codes:<p><pre><code> For some reason, the portrait of Peter Weinberger has always been
our most popular target for picture editing experiments. [1]
</code></pre>
[1]: <a href="http://swtch.com/pjw" rel="nofollow">http://swtch.com/pjw</a>