AER Emu

an Address-Event Imager Emulator for Sensor Networks.


XYZ with Aloha AER		XYZ with COTs camera (emulation platform)

Introduction

Address-Event Respresentation (AER) consists of a way of representing data by an ordered train of addresses, each of them related to the occurrence of an event. AER was first introduced with the intent of approximating the spike trains by which neurons communicate. AER explores the fact that while, on one hand, it is prohibitive for integrated circuits to mimic the massively parallelism of biological systems (a single neuron can make hundreds of thousands of connections), on the other hand ICs can operate at speeds that are several orders of magnitude higher than the typical spike rates.

We argue that AER imagers is a good candidate technology for wireless sensor networks for various reasons:

AER imagers consume μWatts of power;
Image features are extracted at pixel-level, yielding simpler data processing;
Data is automatically prioritized according to relevancy, and irrelevant data is filtered out of the stream;
Due to the nature of the data, reconstruction of an image can be made substantially hard — thus AER imagers are privacy preserving.

Why emulate AER?

AER imagers are not easy to find, especially not in a commercial, off-the-shelf (COTS) manner. Therefore, to study AE imaging in a sensor network context, it is advantageous to employ COTS cameras to emulate AER imagers. Part of our research aims to create a detailed behavioral model for an AER imager architecture. Using this model we are in the process of developing a realistic AER emulator that will allow us to study different architectural alternatives before they are put into silicon. In order to promote the development of AER sensor specifications, and to solicit community feedback on AER architectures and applications, we plan to distribute our AER emulator to the community in two forms: 1) as a desktop tool and 2) as part of a wireless sensor node. Validated design specifications are used to design and fabricate the CMOS AER imagers at E-Lab, led by Eugenio Culurciello at Yale.

Building an AER Emulator

The diagram below illustrates the data flow of the ENALAB AER Emulator software. An input from a COTS USB camera is filtered using traditional image processing techniques and transformed into a stream of events. This is then either saved to a text file, or used to reconstruct an image stream that can be displayed and saved as AVI.

Data flow diagram of AER emulation.

The program's interface allows customization of each step of the data flow above, as can be seen on the screenshot (below). The parameters for each stage is displayed in a column underneath the corresponding stage. Documentation will be available shortly.

Software screenshot.

Emulator Demo Software Download

Enalab AER Emulator v1 beta1

Compatible with Windows 2000 or newer. The user may have to download VideoOCX drivers.

Links and References

ENALAB main page
E-Lab website
T. Teixeira, E. Culurciello, J. H. Park, D. Lymberopoulos, A. Barton-Sweeney, A. Savvides, Address-Event Imagers for Sensor Networks: Evaluation and Modeling, to appear in Information Processing in Sensor Networks, IPSN 2006, SPOTS track

People

Thiago Teixeira, Ph.D. Student - ENALAB
Zhengming Fu, Ph.D. Student -E-LAB
Dimitrios Lymberopoulos, Ph.D. Student - ENALAB
Andrew Barton-Sweeny, Postgraduate Researcher - ENALAB
Eugenio Culurciello, EE Faculty - E-LAB
Andreas Savvides, EE Faculty - ENALAB

ENALAB Presents