Image contrast enhancement using singular value decomposition for gray level images

In this letter analysis the satellite images by using discrete wavelet transform and singular value decomposition. The input image is decomposes into the four frequency subbands by using DWT and estimates the singular value matrix of the low-low subband image and then it reconstructs the enhanced image by applying inverse DWT. The technique is compared with conventional image equalization techniques such as standard general histogram equalization and local histogram equalization as well as state-of-the art techniques such as brightness preserving dynamic histogram equalization. The experimental results show the superiority of the proposed method over conventional methods.