Proposed an algorithm to fuse the multispectral image with the corresponding Panchromatic Image using different methods. The Multispectral images and their corresponding Panchromatic images are collected. Initially the registration process are performed. For registration process, consider Panchromatic image as the reference image and the MS image as the sensed image. The transformation from MS image to PAN image represented by estimation of transformation parameters. To calculate the transformation parameter by affine transformation model. After that image fusing of multispectral and PAN images are fused using iteratively upadate the objective function. In fusing process, initially construct the objective function in order to improve the fusion quality. To analyze the fusion quality by estimating the ERGAS index, with the help of resolution of the high resolution of PAN image and low resolution of MS image. When the ERGAS index obtains the minimum value, the corresponding transformation parameters are the solution of the joint optimization process. This estimation of objective function performed by iteratively Optimization Algorithm.