1. INTRODUCTION
With the launch of satellites, the satellite imagery has played an important role in agriculture, environment and mining. The satellite is usually equipped with two kinds of imaging devices, multispectral (MS) sensors and panchromatic (PAN) sensors. MS images are with high spectral resolution and low spatial resolution, while PAN images are with low spectral resolution and high spatial resolution. To obtain the images with both high spectral and high spatial resolutions, pansharpening that fuses the low resolution MS (LRMS) images and PAN images has received much attention from the remote sensing field.