Plextek (Great Chesterford, UK) has developed a suite of image processing functions that allow video to be sent over data links with widely-varying bit rates, such as wireless links deployed in demanding environments. By identifying objects and areas of interest in the image and intelligently assigning different amounts of image compression, video quality can be maintained for important image areas while reducing it in others.
Together with real-time motion and target tracking to identify important elements of the scene, the system can adapt dynamically as the link quality varies, allowing users freedom to concentrate on the important aspects of a scene. “Many image compression techniques are designed to compress the entire area of the scene at a fixed level of quality -- but when the data link varies, the severe compression may not give enough quality to evaluate important objects in the scene,” says Graham Tootell, project engineer in Plextek’s Image Processing group. “Our processing provides better resolution for specific areas while trading it in others, giving better overall system performance. This has advantages, for example for cameras deployed in the field for video and security surveillance.”
Plextek’s software processing can be applied to a range of cameras and sensors, including cameras incorporating megapixel sensors. In this situation the processing can maintain the higher definition in specific areas but allow the use of standard video channels.