SAN JOSE, Calif. — Vendors demonstrated technologies for adding gesture recognition and social networking to cable TV services at the annual CableLabs Summer Conference.

Startup PrimeSense (Tel-Aviv, Israel) won an informal poll of cable TV executives as having the best new product at the event. The company showed a modified Web camera that could recognize gestures and project a virtual touch screen using a modified Web camera with a $20 bill of materials.

The PrimeSense system adds an infrared projector and a proprietary controller chip to a Web cam that links to a cable set-top box via USB. The resulting system tracks motions to a centimeter resolution from viewers seated ten feet away.

"We are essentially projecting a touch screen out in front of you so you can reach out from the sofa and touch buttons or navigate using simple hand gestures with or without remote control," said Suneil Mishra, vice president of sales and marketing for PrimeSense.

PrimseSense hopes to announce OEMs using its chip before the end of the year to create interactive interfaces for a range of consumer systems. The chip will be in production soon, Mishra said.

Competitors include Canesta Inc., demonstrated by Hitachi earlier this year, and 3DV Systems, reportedly acquired by Microsoft in early June.

Of 11 total demonstrations at the CableLabs showcase this week, there were "two or three examples of social networking that could be deployed in the near term on cable platforms," said David Reed, chief strategy officer of CableLabs.

The demos included a so-called cloud-casting demo from Alcatel-Lucent using the protocols for the cable operators' Tru2Way network. It showed a way of letting users upload personal videos to share with friends over a cable-TV infrastructure.

In addition, AudioCodes showed a voice over IP system that could offer audio quality higher than standard phones. Ceton Corp. showed a multi-channel cable card that could receive six HDTV streams on a Windows 7 PC.

In other demos, Elemental Technologies showed a video transcoding server based on graphics processors. Openet, the Tandberg division of Ericsson and Verivue showed separate products that let cable operators send content to multiple devices in the home.

The vendor demos showed "even in tough economic times there is a robust development effort behind cable operators," said Reed of CableLabs.