EVALUATION OF DWT BASED IMAGE FUSION WITH THREE DIFFERENT RESAMPLING METHODS

Abstract: The science of satellite observation is called remote sensing. In optical remote sensing, the multispectral (MS) image which contains color information is produced by three sensors covering the red, green and blue spectral wavelengths. Because of the trade-off imposed by the physical constraint between spatial and spectral resolutions, the MS image has poor spatial resolution. On the contrast, the panchromatic (PAN) images has high spatial resolution but without color information. Image fusion can combine the geometric detail of the PAN image and the color information of the MS image to produce a high-resolution MS image. - Image fusion is powerful tool to include the detail information into single image from many images taken from different sensors at different instants This study is carried out using Cartosat-2 Panchromatic image with 1m spatial resolution and Resource sat-1 Liss-IV sensor of 3 bands b2 , b3 and b4 with 5.8 m spectral resolution. The images are to be pre-processed to accommodate the fusion algorithm requirements. This pre-processing may include registration and resampling of the MS and PAN images. Image Resampling is the mathematical technique used to alter the scale of an image. Popularly known basic interpolation techniques are nearest neighbor, bilinear and bicubic. These resampled MS and PAN images are fused by using Discrete Wavelet Transformations (DWT) technique. Fusion results are evaluated numerically; and quality metrix are calculated between the fused image and MS image.  

Keywords: Resampling, DWT, Image Fusion, Image Processing