With the development of spaceborne imaging sensors, a unified image fusion approach suitable for all employed imaging sources becomes necessary. In this work, we first investigate the recently proposed hyperspherical color sharpening (HCS) method which is specifically designed for the WorldView-2 imagery. It can then be shown that the HCS method is indeed a Brovey-transform-like (BT) approach. In this paper, the performance analysis of BT-like and intensity-hue-saturation-like (IHS) methods is provided. In addition, to solve the problem of spectral mismatch, viable solutions are proposed and rigorously tested. For controlling the trade-off between the spectral and spatial information in fused images, smoothing-filter-based intensity modulation (SFIM) technique is incorporated into the IHS-BT-SFIM fusion approach with five different modules. It is demonstrated that this adjustable approach is capable of quickly merging the massive volume of data and providing a satisfactory control of color and spatial information for a wide variety of input scenes.