Towards Objection Detection under IoT Resource Constraints: Combining Partitioning, Slicing and Compression

Abstract

We consider deploying an object detection pipeline over a heterogeneous IoT network. We consider a setting where a camera-equipped IoT edge node communicates wirelessly with a cloud server. In many real-world domains, the bandwidth of this connection is constrained and variable, while the edge node may have insufficient compute resources to perform complex machine learning tasks such as object detection. Building on prior work in the image classification space, we propose an approach for detection that first partitions a deep neural network model at a given layer and then applies progressive transmission of intermediate convolutional filter maps. This capability can be exercised in response to dynamically varying network bandwidth. Further, we consider the application of lossy compression to the filter maps themselves, exposing a broader set of communication compression trade-offs that includes a choice for the representation size transmitted as well as the lossy compression level applied. The model is trained specifically to optimize distributed operation including the need for the cloud stage to decode and process a variable size representation. We investigate the performance of this approach in terms of a detection accuracy-communication cost trade-off. We compare to approaches that compress images and perform detection using cloud offload. Our results show that our approach achieves a significantly better detection accuracy-communication cost trade-off compared to cloud offload of JPEG compressed images.