The subject matter of this specification can be implemented in, among other things, a computer-implemented method including detecting positions of objects of a specific type within an ordered sequence of images. The method includes estimating one or more intermediate positions of one or more intermediate instances of an object in one or more intermediate images within the ordered sequence of images between an initial image and a subsequent image based on an initial position of an initial instance of the object in the initial image and a subsequent position of a subsequent instance of the object in the subsequent image. The method includes providing a list of the objects for presentation. The method includes receiving a selection of the object from the list. The method includes performing an operation on the initial instance, the intermediate instances, and the subsequent instance of the object.