A survey of visual sensor network platforms <s> Other platforms <s> eCAM is an ultra-compact, high data-rate wireless sensor node(WSN) with a miniature camera. It is constructed by interfacing a VGA quality digital video camera with the Eco node. The purpose of this demo is to show that Eco is not only one of the world's smallest self-contained WSNs, but its expansion capability facilitates the construction of new sensing systems over its expansion port. The results show that Eco is not only ultra-compact but also much higher performance than sensor nodes in its class. <s> BIB001 </s> A survey of visual sensor network platforms <s> Other platforms <s> We introduce Meerkats, a wireless network of batteryoperated camera nodes that can be used for monitoring and surveillance of wide areas. One distinguishing feature of Meerkats (when compared, for example, with systems like Cyclops [10]) is that our nodes are equipped with sufficient processing and storage capabilities to be able to run relatively sophisticated vision algorithms (e.g., motion estimation) locally and/or collaboratively. In previous work [9, 8, 7] we analyzed the energy consumption characteristics of the Meerkats nodes under different duty cycles, involving different power states of the system’s components. In this paper we present an analysis of the performance of the surveillance system as a function of the image acquisition rate and of the synchronization between cameras nodes. Our ultimate goal is to optimally balance the trade-off between application-specific performance requirements (e.g., event miss rate) and network lifetime (as a function of the energy consumption characteristics of each node). <s> BIB002 </s> A survey of visual sensor network platforms <s> Other platforms <s> This paper describes a new smart camera mote with a high performance SIMD (single-instruction multiple-data) processor. Previous versions of our camera mote were equipped with IC3D, a line-based processor. The mote described in this paper is equipped with Xetal-II, a processor designed for frame-based real-time video analysis. The processor uses 320 processing elements in parallel to achieve performance figures of more than 100 GOPS with a power consumption of 600 mWatt at peak performance. The IC has a 10 Mbit internal memory cache to store and work on 4 VGA frames. The internal bandwidth to this memory is more than 1.5 Tbit/s allowing multiple passes over the images within frametime. Augmented with hardware tools for object processing, the new mote opens the door for embedded active vision applications and other iterative techniques such as watershedding and distance transforms in collaborative camera networks. <s> BIB003 </s> A survey of visual sensor network platforms <s> Other platforms <s> Sensor networks have been a very active area of research in recent years. However, most of the sensors used in the development of these networks have been local and non-imaging sensors such as acoustics, seismic, vibration, temperature, humidity, etc. The development of emerging video sensor networks poses its own set of unique challenges, including high bandwidth and low latency requirements for real-time processing and control. This paper presents a systematic approach for the design, implementation, and evaluation of a large-scale, software-reconfigurable, wireless camera network, suitable for a variety of practical real-time applications. We take into consideration issues related to the hardware, software, control, architecture, network connectivity, performance evaluation, and data processing strate-gies for the network. We perform multi-objective optimization on settings such as video resolution and compression quality to provide insight into the performance trade-offs when configuring such a network. <s> BIB004
In addition to the nine aforementioned VSN platforms, there are several other platforms with imaging and wireless communications capabilities such as eCAM BIB001 , WiCa BIB003 and VideoWeb BIB004 . However, these platforms are either not sufficiently characterized or do not satisfy our criteria to be a VSN platform (e.g., VideoWeb is not battery-operated). In this subsection we provide summarized information for these platforms. BIB002 eCAM BIB001 is a miniature platform (total size of the platform is less than 1 cm 3 ) created by integrating a VGA video camera with the Eco networking platform. The camera module (C328-7640) can operate as a video camera or as a still camera with built-in JPEG compression capability. The image sensor within the camera is OmniVision OV7640. The camera module supports various image resolutions (GVA/CIF/160×128/80×64) and it can capture up to 30 fps. Network platform includes a wireless radio (Nordic VLSI nRF24E1), which operates at 2.4 GHz range and can transmit up to 1 Mbps data rate. eCAM is designed for applications that require very small form factor platforms; therefore, it has very limited in-node processing capabilities. Hence it is not in the same class with the aforementioned VSN platforms. WiCa BIB003 is a wireless smart camera based on an SIMD (Single Instruction Multiple Data) processor, which is a technique employed to achieve data level parallelism. WiCa has four main components: VGA color image sensor, SIMD processor (IC3D-a Xetal family of SIMD processor) for low level image processing suitable for parallel processing, a general purpose processor for higher level operations (ATMEL 8051), and a communications module (Phillips Aquis Grain ZigBee module developed around ChipCon CC2420). Both processors have access to a dual port RAM that enables them to share a common workspace, which enables both processors to collectively use the data and even pipeline the processing of data in a flexible manner. The software for IC3D is written in C++ and they are designed in such a way that any image processing operation performed on each image line is completed within a single clock cycle. Such an approach is necessary to utilize the full capacity of an SIMD processor. WiCa platform is used in several applications including distributed face detection. WiCa is promising VSN platform with its unique design and its use of an SIMD processor rather than an FPGA chip for low-level image processing operations. However, energy dissipation characteristics of WiCa (i.e., energy dissipation measurements for the whole platform) are not reported, thus, we do not include WiCa among the VSN platforms we use for platform categorization. VideoWeb BIB004 is a software-reconfigurable high-bandwidth wireless network architecture using IP cameras and wireless bridges and routers. No on-camera processing is performed in VideoWeb approach; instead tiered-processing of the video data is achieved with low-level processing servers (e.g., for detecting moving objects) and high-level processing servers (e.g., for face recognition). Multi-objective optimization on video resolution and compression quality are performed to provide insights on performance trade-offs. The designers of VideoWeb choose to use power adapters considering that for long-term applications batterypowered cameras are not appropriate.