Image fusion is the process to combine two or more images such that the enhanced output image contains all the relevant information. This paper aims to evaluate algorithms that fuses multi-focus images. With an aim to enhance the sharpness of the final fused image and also to reduce the computational complexity, a novel method is proposed that uses the Sobel operator. This method is evaluated using mean squared error, peak signal to noise ratio, structural similarity index, entropy, mutual information, image quality index and run time. The optimum weights required to fuse two images are calculated from image statistics using genetic algorithm (GA). The results show that this superposition method performs at par with discrete wavelet transform (DWT) with reduction in run time. © 2016 IEEE.