Optical image data fusion by using intensity operation on HSI transformation

The studies on merging satellite images have been done and some new methods were suggested. Especially, merged multispectral images such as Landsat/TM data with SPOT PA data are available for remote sensing application, for example, land cover classification. The most popular method for merging satellite images is a technique by using RGB-HSI transformation. The authors actually attempted to merge images by using this method, but it caused some problems. An obtained fused image contains high resolution information which comes from a panchromatic image. But the density level of the obtained fused image is different from that of original color image. Especially, this problem was caused when a color composite image contains the near infrared band. This is because panchromatic images do not have the information of near infrared band. The authors pay attention to the intensity of satellite images to solve these problems. Two methods, “Intensity Preserved Method” and “Intensity Adjusted Method”, were proposed and compared. The authors have obtained an effective result for both methods