ReSFlow: A Remote Sensing Imagery Data-Flow for Improved Model Generalization
Dalton Lunga, Jacob Arndt, Jonathan Gerrand, Robert Stewart · IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing · 2021
As satellite imagery collections continue to grow at an astonishing rate, so is the demand for automated and scalable object detection and segmentation. Scaling computational activities demand models that generalize well across various challenges that can hamper progress, including 1) diverse imaging and geographic conditions, 2) sampling bias in training data, 3) manual ground truth collection, 4) tooling for model reuse and accountability assessment, and 5) poor model training strategies. A great deal of progress has been made on these challenges. We contribute to the improvement through further development of ReSFlow, a workflow that breaks the problem of model generalization into a collection of specialized exploitations. ReSFlow partitions imagery collections into homogeneous buckets equipped with exploitation models trained to perform well under each bucket's specific context. Essentially ReSFlow aims for generalization through stratification. Therefore, within a bucket, exploitation is a homogeneous process that mitigates heterogeneity challenges, including the number of training data and data biases that can occur over varied conditions. Furthermore, custom model architectures and rich training strategies effective for within bucket conditions can be developed. Meanwhile, across bucket performance metrics support systematic views of the workflow leading to optimal data labeling allocations and indications that further specialization (and retooling of models) is warranted. Herein, we discuss the formation of models during the framework's "Offline Initialization" stage. Lastly, we exploit the inherent parallelism due to bucketing to introduce model reuse and demonstrate efficacy by reducing an 89-day manual data labeling cost to zero-days in a new area of interest.