Most of the recent remote sensing sensors produce higher radiometric resolution than those display devices showing images. Therefore DRC (Dynamic Range Compression) is applied to accommodate original image with large bit-depth to the showing device with less bit-depth. Common stretch methods achieve the DRC with linear line or non-linear curve mapping. The linear stretch loses the details of the highest and lowest luminance area, and the non-linear stretch causes the color distortion issue after the fusion of panchromatic (Pan) and multi-spectrum (MS) image. This paper develops an approach to enhance unapparent features in the Pan image using wavelet fusion method which combine sub-images coming from the same original Pan image. Those sub-image formed by different stretch method for enhancing the radiometric visualization and keeping better correlation with the original color information. According to the experimental result, this approach can apply to not only the airborne but the spaceborne image to produce ideal pan-sharpened product.
The image fusion technique is to maximize the information in images at same area or object taken by different sensors. It
enhances unapparent features at each image and wildly applied at remote sensing, medical image, machine vision, and
military identification. In remote sensing, the latest sensors usually provide 11-bit panchromatic data which compose
more radiometric information; however the standard visual equipment can only produce 8-bit resolution content that
limits the analysis of imagery on the screen or paper. This paper shows how to preserve the original 11-bit information
after the DRA (Dynamic Range Adjustment) approaches and keep the output from color distortion during the following
pan/multi-spectrum image fusion process. We propose a good dynamic range compression method converting the
original IKONOS panchromatic image into high, low luminance and typical linear stretched images and using wavelet
fusion to enhance the radiometric visualization and keeping good correlation with the multi-spectrum images in order to
produce fine pan-sharpened product.