Improving Recognition of Complex Aerial Scenes Using a Deep Weakly Supervised Learning Paradigm

Categorizing highly complex aerial scenes is quite strenuous due to the presence of detailed information with a large number of distinctive objects. Recognition happens by first deriving a joint relationship within all these distinguishing objects, distilling finally to some meaningful knowledge that is subsequently employed to label the scene. However, something intriguing is whether all this captured information is actually relevant to classify such a complex scene? What if some objects just create uncertainty with respect to the target label, thereby causing ambiguity in the decision-making? In this letter, we investigate these questions and analyze as to which regions in an aerial scene are the most relevant and are inhibiting in determining the image label accurately. However, for such aerial scene classification (ASC) task, employing supervised knowledge of experts to annotate these discriminative regions is quite costly and laborious, especially when the data set is huge. To this end, we propose a deep weakly supervised learning (DWSL) technique. Our classification-trained convolutional neural network learns to identify discriminative region localizations in an aerial scene solely by utilizing image labels. Using the DWSL model, we significantly improve the recognition accuracies of highly complex scenes, thus validating that extra information causes uncertainty in decision-making. Moreover, our DWSL methodology can also be leveraged as a novel tool for concrete visualization of the most informative regions relevant to accurately classify an aerial scene. Finally, our proposed framework yields a state-of-the-art performance on the existing ASC data sets.