1. A method for creating a fused image from an image pair comprising a high resolution panchromatic image and lower resolution multi-spectral image, comprising: obtaining image data defining a first image of a panchromatic image type, said first image having a first spatial resolution and a first spectral resolution; obtaining image data defining a second image of a multi-spectral image type, said second image having a second spatial resolution lower than said first spatial resolution and a second spectral resolution higher than said first spectral resolution; concurrently calculating a point-spread function for down-sampling said first image to said second spatial resolution, and a set of weights for down-sampling said second image to said first spectral resolution; using said set of weights, forming a fused image having said first spatial resolution and said second spectral resolution; wherein said point-spread function and said set of weights are specifically optimized to the unique characteristics of the image pair.