CamTuner: Reinforcement-Learning based System for Camera Parameter Tuning to enhance Analytics

Complex sensors like video cameras include tens of configurable parameters, which can be set by end-users to customize the sensors to specific application scenarios. Although parameter settings significantly affect the quality of the sensor output and the accuracy of insights derived from sensor data, most end-users use a fixed parameter setting because they lack the skill or understanding to appropriately configure these parameters. We propose CamTuner, which is a system to automatically, and dynamically adapt the complex sensor to changing environments. CamTuner includes two key components. First, a bespoke analytics quality estimator, which is a deep-learning model to automatically and continuously estimate the quality of insights from an analytics unit as the environment around a sensor change. Second, a reinforcement learning (RL) module, which reacts to the changes in quality, and automatically adjusts the camera parameters to enhance the accuracy of insights. We improve the training time of the RL module by an order of magnitude by designing virtual models to mimic essential behavior of the camera: we design virtual knobs that can be set to different values to mimic the effects of assigning different values to the camera's configurable parameters, and we design a virtual camera model that mimics the output from a video camera at different times of the day. These virtual models significantly accelerate training because (a) frame rates from a real camera are limited to 25-30 fps while the virtual models enable processing at 300 fps, (b) we do not have to wait until the real camera sees different environments, which could take weeks or months, and (c) virtual knobs can be updated instantly, while it can take 200-500 ms to change the camera parameter settings. Our dynamic tuning approach results in up to 12% improvement in the accuracy of insights from several video analytics tasks.