Yes Awstats is a very good stat compiler...however unless you've backdoored my site and account you're just assuming without any actual figures. And I don't just use Quantcast, Quantcast is just an added/extra way I track statistics. I don't rely simply upon one source.
Thumbs are not counted as views, they are counted as hits. This is laid out in the stats information. Plus, when I was using phpThumb the server was being hit with literally millions of image requests from a problem related to phpThumb, again my site was shut down, while the host cleaned up their servers, they limited the requests re-instated my site and advised me to change templates as soon as possible, which I did a couple months ago. The stat page views did not reflect the image requests.