Brightness and Resolution Enhancement of Satellite Images using SVD and DWT

摘要

A new satellite image resolution and brightness enhancement technique based on the discrete wavelet transform (DWT) and singu lar value decomposition (SVD) has been proposed. Satellite images are used in many applications such as geosciences studies, astronomy, and geographical information systems. One of the most important quality factors in images comes from its resolution. The technique decomposes the input image into the four frequency sub bands by using DWT and estimates the singular value matrix of the low – low sub band image, and, then, it reconstructs the enhanced image by applying inverse DWT. The technique also estimates the singular value matrix of the low – low sub band of histogram equalized image and normalize both singular value matrices to obtain brightness enhanced image. The technique is compared with conventional image equalization techniques such as standard gener al histogram equalization and local histogram equalization, as well as state of the art techniques such as brightness preserving dynamic histogram equalization and singular value equalization. The experimental results show the superiority of the proposed m ethod over conventional and state of the art technique.