System and method for combining color information with spatial information in multispectral images

摘要

An image processing system combines higher-resolution panchromatic images and lower resolution multispectral images using a hyperspherical color space pan-sharpening technique. By converting the multispectral images into a hyperspherical color space, the intensities of the multispectral images can be intensity matched to the intensities of the panchromatic image and then retransformed back to the original color space. The intensity matching can utilize a number of techniques, including, but not limited to, direct substitution of the intensities of the panchromatic image for the intensities of the multispectral images, modification of the intensities of the multispectral images based on predefined statistical models and modification of the intensities of the multispectral images based on dynamically generated statistical models and a selected sharpening parameter β.

主权项

1. An image processing system for combining at least a portion of a panchromatic image block at a first resolution with at least corresponding cogeolocated portions of n spectral band image blocks of a second resolution lower than the first resolution, the system comprising:
circuitry for upsampling the corresponding portions of the n spectral band image blocks at the second resolution to form n upsampled spectral band image blocks, where n is an integer that is at least as large as four; circuitry for transforming the n upsampled spectral band image blocks to a hyperspherical color space to form hyperspherical color space image blocks including, for each pixel in the hyperspherical color space image block, a hyperspherical intensity and n−1 hyperspherical angles; circuitry for intensity matching the intensities of the hyperspherical color space image blocks with intensities of corresponding pixels in the panchromatic image block to form intensity adjusted hyperspherical color space image blocks; and circuitry for reverse transforming the intensity adjusted hyperspherical color space image blocks into n reverse transformed spectral band image blocks, wherein the circuitry for upsampling comprises circuitry for performing a zero order hold on the n spectral band image blocks of a second resolution to generate pixels at the first resolution.