Abstract: The smoothing of images is a very important step in the stitching process of images. An improved seamless image stitching algorithm based on the wavelet direction contrast is presented by the analysis of some available smoothing algorithms. The improved algorithm makes the luminance of the two images same first, then the multiresolution decomposition of the two images is implemented by using wavelet transformation and the images are smoothed by an improved wavelet direction contrast algorithm. The simulation results were assessed with some objective evaluation standards. The results show that this algorithm can make two images smoothly in despite of a great gray difference between the two images. Therefore, it is independent of the ambient light and can make the details of images clear.