Starfish: Resilient image compression for AIoT cameras

Abstract

Cameras are key enablers for a wide range of IoT use cases including smart cities, intelligent transportation, AI-enabled farms, and more. These IoT applications require cloud software (including models) to act on the images. However, traditional task oblivious compression techniques are a poor fit for delivering images over low power IoT networks that are lossy and limited in capacity. The key challenge is their brittleness against packet loss; they are highly sensitive to small amounts of packet loss requiring retransmission for transport, which further reduces the available capacity of the network. We propose Starfish, a design that achieves better compression ratios and is graceful with packet loss. In addition to that, Starfish features content-awareness and task-awareness, meaning that we can build specialized codecs for each application scenario and optimized for task objectives, including objective/perceptual quality as well as AI tasks directly. We carefully design the DNN architecture and use an AutoML method to search for TinyML models that work on extremely low power/cost AIoT accelerators. Starfish is not only the first image compress framework that works on a $3 AIoT accelerators but also outperforms JPEG, a well-established baseline, by up to 3x, in terms of bandwidth efficiency and up to 2.5x as efficient in energy consumption. It also features graceful and gradual performance degradation in the presence of packet loss. The application-level simulation indicates that Starfish could deliver 3.7x images while providing better image quality.