Embedded systems can already capture data produced at high rates, and embedded CPU and sensor performance are still rapidly improving. Radio technology, however, can not keep pace, and will not in the future due to known physical limits of shared communication channels. This leads to a fundamental gap between the data a sensor network node can collect and the data it can transmit back for analy...

Motion description of objects time evolution is often bit-rate wasting even if computed at a low fixed ffame rate. Bit-rate reduction can be achieved taking advantage of the inactivity periods: in such time intervals there is no need for motion coding, as an accurate description of the scene can be obtained only considering the frame diflerence information. We propose to estimate the motion bet...

A double stimulus subjective evaluation was performed to determine preferred frame rates at a fixed bit rate for low bit rate video. Stimuli consisted of eight reference color video sequences of size 352 × 240 pixels. These were compressed at rates of 100, 200 and 300 kbps for low, medium, and high motion sequences, respectively, using three encoders and frame rates of 10, 15 and 30 frames per ...

This paper presents a variable-rate CELP codec which achieves good communications speech quality at an average rate of about 3 kb/s. The codec operates as a source-controlled variable rate coder with rates of 4.9 kb/s for voiced and transition sounds, 3.0 kb/s for unvoiced sounds and 670 b/s for silent frames. New techniques used in the codec include prediction of the xed codebook target vector...