说明：  In remote sensing applications, image acquired from space borne satellites are of diverse spatial, spectral and temporal resolutions. Several situations in image interpretation require high spatial information and high spectral information in a single image. But the existing sensors do not have the ability to provide such information either by design or because of observational constraints. Thus the complementary information different sensors are integrated using the technique called image fusion to get a resultant fused image which is more informative than any of the given input images.