DWT based Satellite Image Resolution Enhancement Technique

Satellite images are being used in many fields of research. One of the major issues of these types of images is their resolution. So it is essential to have high resolution satellite images. Resolution enhancement of these images has always been a major issue to extract more information from them. Wavelet domain based methods have proved as most efficient technique serving for the required purpose. Interpolation in image processing is a well-known method to increase the resolution of a digital image. Many interpolation techniques have been developed to increase the image resolution. The three different types of interpolation techniques are nearest neighbor, bilinear and bicubic interpolation .several image enhancement techniques have been proposed. In this paper, I propose a new satellite image resolution enhancement technique based on the interpolation of the high-frequency sub bands obtained by discrete wavelet transform (DWT) and the input image. The proposed resolution enhancement technique uses DWT to decompose the input image into different sub bands. Then, the high-frequency sub band images and the input low-resolution image have been interpolated, followed by combining all these images to generate a new resolution-enhanced image by using inverse DWT. In order to achieve a sharper image, an intermediate stage for estimating the high-frequency sub bands has been proposed. The proposed technique has been tested on satellite benchmark images. The quantitative (peak signal-to-noise ratio and root mean square error) and visual results show the superiority of the proposed technique over the conventional and state-of-art image resolution enhancement techniques.