Visual Sensors Hardware Platforms: A Review

In the last two decades, visual sensor networks have been developed to gather visual data from different monitoring scenarios, directly contributing to the maturation of the Internet of Things (IoT) applications landscape. Such developments have evolved according to the releasing of new hardware platforms for the construction of sensor nodes, as well as the availability of low-power compatible cameras. Since sensor networks deployed for visual data sensing are inherently complex and resource-demanding, knowing how visual sensors have been created can give a better perception of how those networks have evolved and which innovations are expected for the next years. This article reviews past developments of visual sensors concerning the employed hardware platforms and cameras, providing a taxonomy for them and discussing how to choose the most appropriate hardware when designing and implementing modern (wireless) visual sensor networks.