This paper deals with the computation of homographies from two views in a multi-plane scene. In the general case, homographies can be determined using four matched points or lines belonging to planes. We propose an alternative method when a first homography has been obtained, and then three matches are sufficient to compute a second homography. This process is based on the geometric constraint introduced by the first homography. In this work, the extraction and matching of features, points or lines, is automatically performed using robust techniques. Experimental results with synthetic data and real images show the advantages of this approach. Besides, the performance using points or lines as image features is compared.