COMPONENT SUBSTITUTION NETWORK FOR PAN-SHARPENING VIA SEMI-SUPERVISED LEARNING
Pan-sharpening refers to the technology which fuses a low resolution multispectral image (MS) and a high resolution panchromatic (PAN) image into a high resolution multispectral image (HRMS). In this paper, we propose a Component Substitution Network (CSN) for pan-sharpening. By adding a feature exchange module (FEM) to the widely used encoder-decoder framework, we design a network following the general procedure of the traditional component substitution (CS) approaches. Encoder of the network decomposes the input image into spectral feature and structure feature. The FEM regroups the extracted features and combines the spectral feature of the MS image with the structure feature of the PAN image. The decoder is an inverse process of the encoder and reconstructs the image. The MS and the PAN image share the same encoder and decoder, which makes the network robust to spectral and spatial variations. To reduce the burden of data preparation and improve the performance on full-resolution data, the network is trained through semi-supervised learning with image patches at both reduced-resolution and full-resolution. Experiments performed on GeoEye-1 data verifies that the proposed network has achieved state-of-the-art performance, and the semi-supervised learning stategy further improves the performance on full-resolution data.