Energy-Efficient Image Recognition System for Marine Life

This article focuses on designing an energy-efficient image recognition system for marine monitoring. One of the main challenges of an underwater imaging system is the strict power consumption constraints due to the limited on-site resources. Considering the need for continuous operation in different water turbidity levels and background illumination conditions, an energy-efficient approach is needed for the effective utilization of the resources. In this work, we propose a recognition framework that will adaptively adjust the system parameters, such as camera frame rate and LED illumination level, based on the environmental conditions to optimize the energy consumption while ensuring a high recognition accuracy. The first part of the proposed decision system contains the convolutional neural network (CNN)-based animal recognition block which is used for obtaining the confidence level for a single frame. The second part is the adaptive decision block that dynamically changes the system parameters and combines the results of the recognition block for multiple frames based on the environmental conditions. In our experiments, we have used nearly 8000 underwater images for training and testing the single frame recognition block and used nearly 200 different video sequences for training and testing the adaptive decision block. Based on measurements of a hardware framework composed of a Raspberry Pi 3 Model B, a Pi NoIR Camera v2.1, and 850 nm LEDs, the proposed system achieves up to 92.7% energy savings with a comparable recognition performance by dynamically changing the frame rate and emitted light intensity based on water turbidity and background illumination level.