Robust Band-Dependent Spatial-Detail Approaches for Panchromatic Sharpening

Pansharpening refers to the fusion of a multispectral (MS) image with a finer spectral resolution but coarser spatial resolution than a panchromatic (PAN) image. The classical pansharpening problem can be dealt with component substitution or multiresolution analysis techniques. One of the most notable approaches in the former class is the band-dependent spatial-detail (BDSD) method. It has been shown state-of-the-art performance, in particular, when the fusion of four band data sets is addressed. However, new sensors, such as the WorldView-2/-3 ones, usually acquire MS images with more than four spectral bands to be fused with the PAN image. The BDSD method has shown limitations in performance in these cases. Thus, in this paper, several BDSD-based approaches are provided to solve this issue getting a robustness of the BDSD with respect to the spectral bands to be fused. The experimental results conducted both at reduced and at full resolutions on four real data sets acquired by the IKONOS, the QuickBird, the WorldView-2, and the WorldView-3 sensors demonstrate the validity of the proposed approaches against the benchmark.

I. Introduction

Since several decades, satellites acquire a huge amount of images of crucial importance for many human tasks. These data are used both as intermediate products or for visual interpretation. The growing needs of very high-resolution products have pushed toward the design of high-performance acquisition devices. Nevertheless, due to physical constraints (PS), very fine spatial and spectral resolutions cannot be achieved exploiting a sole acquisition device. Thus, image fusion techniques represent a viable solution to overcome this issue by fusing high spatial resolution wide spectrum images with multichannel data.