摘要 |
A secondary sensor is provided that senses the same scene as a video camera. The image from the secondary sensor is used to identify areas of the video image corresponding to objects of interest. The identified areas of interest can then be encoded at a finer level of detail than the other areas in the video image. A preferred secondary sensor for detecting animate objects, such as humans in a videoconference scene, is a conventional infrared heat sensor matrix. By encoding the areas of the video image corresponding to ambient temperature regions of the heat sensor matrix at a generally lower level of detail, the available bandwidth can be allocated for transmitting the higher temperature regions at a finer level of detail or a higher frame rate. The secondary image may also be used as a "front end filter" to conventional object recognition applications, thereby increasing the efficiency and accuracy of these applications. |