1. A seismic imaging method that comprises: obtaining partial images of a survey region; stacking the partial images to produce a reference image; and combining the partial images to form an enhanced image, wherein the combining includes: measuring at each point the reference image's similitude to each of the partial images; and determining at each point an enhanced image value from a weighted combination of corresponding values in the partial images, the weighted combination using weights derived from the reference images' similitude at that point to each partial image.