Superpixel-Oriented Thick Cloud Removal Method for Multitemporal Remote Sensing Images

Since the information across all bands of the cloud-contaminated region is missing, thick cloud removal for remote sensing images (RSIs) is still a challenging problem. Recently, the availability of rich spatial-spectral-temporal information for multitemporal RSIs provides the possibility for addressing the thick cloud removal problem. However, existing methods explore the holistic redundancy of multitemporal RSIs and neglect the important semantic clue of multitemporal images. In this letter, we propose a superpixel-oriented thick cloud removal (STORM) model for multitemporal images, where the multitemporal superpixel as the generic unit allows us to exploit redundancy with semantic clue in a low-rank optimization problem. To harness the resultant irregular fourth-order tensor (i.e., multitemporal superpixels) in the optimization problem, we cleverly introduce the weighted tensor to transform the irregular tensor into the regular tensor, which naturally leads to a standard low-rank tensor optimization problem. To tackle the tensor optimization problem, we develop a proximal alternating minimization (PAM)-based algorithm. Extensive simulated and real experiments on multitemporal RSIs acquired by Sentinel-2 and Landsat-8 satellites demonstrate the superior performance of the proposed method over the comparison methods.