Publications de Zichong Chen | EPFL Graph Search

Cooperative Visual Monitoring in Energy-Constrained Wireless Sensor Networks

EPFL2013

How is the Weather: Automatic Inference from Images

Martin Vetterli, Guillermo Barrenetxea Kobas, Albrecht Johannes Lindner, Feng Yang, Zichong Chen

Low-cost monitoring cameras/webcams provide unique visual information. To take advantage of the vast image dataset captured by a typical webcam, we consider the problem of retrieving weather information from a database of still images. The task is to autom ...

2012

Event-Driven Video Coding for Outdoor Wireless Monitoring Cameras

Martin Vetterli, Guillermo Barrenetxea Kobas, Zichong Chen

Reducing communication cost is crucial for outdoor wireless monitoring cameras which are constrained by limited energy budgets. From event detection point of view, traditional video coding schemes such as H.264 are inefficient as they ignore the "meaning" ...

2012

Distributed Successive Refinement of Multiview Images Using Broadcast Advantage

Martin Vetterli, Guillermo Barrenetxea Kobas, Zichong Chen

In environmental monitoring applications, having multiple cameras focus on common scenery increases robustness of the system. To save energy based on user demand, successive refinement image coding is important, as it allows us to progressively request bet ...

Institute of Electrical and Electronics Engineers2012

Share Risk and Energy: Sampling and Communication Strategies for Multi-Camera Wireless Monitoring Networks

Martin Vetterli, Guillermo Barrenetxea Kobas, Zichong Chen

In the context of environmental monitoring, outdoor wireless cameras are vulnerable to natural hazards. To benefit from the inexpensive imaging sensors, we introduce a multi-camera monitoring system to share the physical risk. With multiple cameras focusin ...

Ieee2012

Sensorcam: An Energy-Efficient Smart Wireless Camera for Environmental Monitoring

Martin Vetterli, Paolo Prandoni, Guillermo Barrenetxea Kobas, Zichong Chen

Reducing energy cost is crucial for energy-constrained smart wireless cameras. Existing platforms impose two main challenges: First, most commercial smart phones have a closed platform, which makes it impossible to manage low-level circuits. Since the samp ...

Assoc Computing Machinery2012

Distributed Successive Approximation Coding using Broadcast Advantage: the Two-Encoder Case

Martin Vetterli, Guillermo Barrenetxea Kobas, Zichong Chen

Traditional distributed source coding rarely considers the possible link between separate encoders. However, the broadcast nature of wireless communication in sensor networks provides a free gossip mechanism which can be used to simplify encoding/decoding ...

2010