Xerox Parc has a patent on a type of filter viewer that acts like a looking glass to see the effect of the filter. Every year, someone reinvents it and presents it at some HCI conference, only to be told they can't use it. They are sitting on it, not building it, and also enforcing it.<p>SIFT is a vision technique that is patented and works very well. Patents are getting in the way of commercial progress
<a href="http://en.wikipedia.org/wiki/Scale-invariant_feature_transform" rel="nofollow">http://en.wikipedia.org/wiki/Scale-invariant_feature_transfo...</a><p>Amazon Onc-Click is an absurd patent. If we grew to scale, Tipjoy would probably have had to pay them money, like Apple does.