Energy and Distortion Analysis of Video Compression Schemes in Multi-Hop Wireless Video Sensor Networks

Abstract

Rapid advances in Micro-Electro-Mechanical Systems (MEMS) technology have made possible the existence of tiny sensor nodes equipped with sensing, communication and processing capabil- ities. When sprayed in an area, they are capable of forming a multi-hop wireless network known as Wireless Sensor Network (WSN). Wireless Video Sensor Network (WVSN) - a type of WSNs - comprises of sensor nodes that can capture, process and communicate video frames. However, sensor nodes have limited hardware resources while video processing and commu- nication is a hardware intensive task i.e. requires large memory and bandwidth and high-end processors. Video encoding is a popular method used to reduce the communication overhead in low-energy WVSN. However, it is an inherently complex pro- cess and therefore results in high processing and energy over- head. Several video encoding schemes have been proposed in the recent past which are rather simple to execute. However, an independent, unbiased and thorough empirical analysis of these video encoding techniques has never been done before and hence is a subject of this thesis. In this work, we consider two widely used video encoding paradigms for wireless sensor networks { Predictive Video Cod- ing (PVC) and Distributed Video Coding (DVC). These two paradigms are empirically evaluated using Intel-mote2 which is a state-of-the-art WVSN platform. The analysis has been carried out to characterize the performance of both paradigms in terms of energy e±ciency, compression e±ciency and video distortion. We perform experiments in multi-hop scenarios using video se- quences of di®erent characteristics. Each video sequence has been evaluated using both the inter-frame encoding and intra- frame encoding. The empirical analysis reveals that none of the existing solutions can be readily adopted in all possible scenar- ios. Rather, the codec selection should be based on a particular WVSN application and available resources. We also formulate detailed guidelines to facilitate the selection process.