A method for depth mapping includes receiving an image of a pattern of spots that has been projected onto a scene, which includes a feature having dimensions that are less than twice an average distance between the spots in the pattern that is projected onto the feature. The image is processed so as to find a 3D location of the feature by computing three-dimensional (3D) coordinates of points on the feature based on transverse shifts of the spots in the image. The spots appearing on the feature in the 3D location are connected in order to find depth coordinates of the points on the feature with a resolution finer than a depth increment corresponding to a transverse shift equal to the average distance between the spots in the image.