Camera Networks

Book description

As networks of video cameras are installed in many applications like security and surveillance, environmental monitoring, disaster response, and assisted living facilities, among others, image understanding in camera networks is becoming an important area of research and technology development. There are many challenges that need to be addressed in the process. Some of them are listed below:

- Traditional computer vision challenges in tracking and recognition, robustness to pose, illumination, occlusion, clutter, recognition of objects, and activities;

- Aggregating local information for wide area scene understanding, like obtaining stable, long-term tracks of objects;

- Positioning of the cameras and dynamic control of pan-tilt-zoom (PTZ) cameras for optimal sensing;

- Distributed processing and scene analysis algorithms;

- Resource constraints imposed by different applications like security and surveillance, environmental monitoring, disaster response, assisted living facilities, etc.

In this book, we focus on the basic research problems in camera networks, review the current state-of-the-art and present a detailed description of some of the recently developed methodologies. The major underlying theme in all the work presented is to take a network-centric view whereby the overall decisions are made at the network level. This is sometimes achieved by accumulating all the data at a central server, while at other times by exchanging decisions made by individual cameras based on their locally sensed data.

Chapter One starts with an overview of the problems in camera networks and the major research directions. Some of the currently available experimental testbeds are also discussed here. One of the fundamental tasks in the analysis of dynamic scenes is to track objects. Since camera networks cover a large area, the systems need to be able to track over such wide areas where there could be both overlapping and non-overlapping fields of view of the cameras, as addressed in Chapter Two: Distributed processing is another challenge in camera networks and recent methods have shown how to do tracking, pose estimation and calibration in a distributed environment. Consensus algorithms that enable these tasks are described in Chapter Three. Chapter Four summarizes a few approaches on object and activity recognition in both distributed and centralized camera network environments. All these methods have focused primarily on the analysis side given that images are being obtained by the cameras. Efficient utilization of such networks often calls for active sensing, whereby the acquisition and analysis phases are closely linked. We discuss this issue in detail in Chapter Five and show how collaborative and opportunistic sensing in a camera network can be achieved. Finally, Chapter Six concludes the book by highlighting the major directions for future research.

Table of Contents: An Introduction to Camera Networks / Wide-Area Tracking / Distributed Processing in Camera Networks / Object and Activity Recognition / Active Sensing / Future Research Directions

Table of contents

  1. Preface
  2. An Introduction to Camera Networks
    1. Research directions
      1. Camera Network Topology
      2. Wide Area Tracking
      3. Distributed Processing
      4. Camera Network Control (ACTIVE vision)
      5. Mobile Camera Networks
      6. Simulation in Camera Networks
      7. Experimental Testbeds
      8. Application Domains
    2. Organization of the book
  3. Wide-Area Tracking
    1. Review of Multi-Target Tracking Approaches
      1. Kalman Filter-Based Tracker
      2. Particle Filter-Based Tracker
      3. Multi-Hypothesis Tracking (MHT)
      4. Joint Probabilistic Data Association Filters (JPDAF)
    2. Tracking in a Camera Network - Problem Formulation
    3. A Review on Camera Network Tracking
    4. On-Line Learning Using Affinity Models
    5. Tracklet Association Using Stochastic Search
    6. Person Reidentification
    7. Learning a Camera Network Topology
    8. Consistent Labeling with Overlapping Fields of View
    9. Conclusions
  4. Distributed Processing in Camera Networks
    1. Consensus Algorithms for Distributed Estimation
    2. Decentralized and Distributed Tracking
      1. Decentralized Tracking
      2. Distributed Tracking
    3. Consensus Algorithms for Distributed Tracking
      1. Mathematical Framework
      2. Extended Kalman-Consensus Filter for a Single Target
      3. JPDA-EKCF for Tracking Multiple Targets
      4. Handoff in Consensus Tracking Algorithms
      5. Example of Distributed Tracking using EKCF
      6. Sparse Networks and Naive Nodes - The Generalized Kalman Consensus Filter
    4. Camera Network Calibration
      1. Distributed Data Association
      2. Distributed Calibration
      3. Distributed Pose Estimation
    5. Conclusions
  5. Object and Activity Recognition
    1. Object Recognition
      1. Object Recognition Under Resource Constraints
    2. Time-Delayed Correlation Analysis
      1. Scene Decomposition and Activity Representation
      2. Cross Canonical Correlation Analysis
      3. Applications
    3. Activity Analysis Using Topic Models
      1. Probabilistic Model
      2. Labeling Trajectories into Activities
    4. Distributed Activity Recognition
      1. Consensus for Activity Recognition
    5. Conclusions
  6. Active Sensing
    1. Problem Formulation
      1. Active Sensing of Dynamical Processes
    2. Review of Existing Approaches
    3. Collaborative Sensing in Distributed Camera Networks
      1. System Modeling
      2. Distributed Optimization Framework
      3. Choice of Utility Functions
      4. Negotiation Mechanisms
      5. Example Scenarios
      6. Results in Example Scenarios
    4. Opportunistic sensing
      1. Global Utility
      2. Experiments
    5. Conclusions (1/2)
    6. Conclusions (2/2)
  7. Future Research Directions
  8. Bibliography (1/3)
  9. Bibliography (2/3)
  10. Bibliography (3/3)
  11. Authors' Biographies

Product information

  • Title: Camera Networks
  • Author(s): Amit Roy-Chodhury, Bi Song
  • Release date: January 2012
  • Publisher(s): Morgan & Claypool Publishers
  • ISBN: 9781608456758