Multi-Temporal Scene Classification and Scene Change Detection with Correlation based Fusion.

Classifying multi-temporal scene land-use categories and detecting their semantic scene-level changes for remote sensing imagery covering urban regions could straightly reflect the land-use transitions. Existing methods for scene change detection rarely focus on the temporal correlation of bi-temporal features, and are mainly evaluated on small scale scene change detection datasets. In this work, we proposed a CorrFusion module that fuses the highly correlated components in bi-temporal feature embeddings. We first extract the deep representations of the bi-temporal inputs with deep convolutional networks. Then the extracted features will be projected into a lower-dimensional space to extract the most correlated components and compute the instance-level correlation. The cross-temporal fusion will be performed based on the computed correlation in CorrFusion module. The final scene classification results are obtained with softmax layers. In the objective function, we introduced a new formulation to calculate the temporal correlation more efficiently and stably. The detailed derivation of backpropagation gradients for the proposed module is also given. Besides, we presented a much larger scale scene change detection dataset with more semantic categories and conducted extensive experiments on this dataset. The experimental results demonstrated that our proposed CorrFusion module could remarkably improve the multi-temporal scene classification and scene change detection results.