1. A method for imaging a portion of a body of a subject that undergoes motion, the method comprising: using an image-acquisition device, acquiring a plurality of image frames of the portion of the subject's body; using a processor, generating an enhanced movie of the portion of the subject's body, in which a vicinity of a given feature of the image frames is enhanced, by: automatically identifying the given feature in each of the plurality of acquired image frames, aligning at least some of the image frames of the plurality of acquired image frames by aligning the given feature in the at least some of the image frames, and averaging respective sets of two or more of the aligned frames to generate a plurality of averaged image frames, in which the vicinity of the given feature in the averaged image frames is enhanced, by components of the aligned frames that are not in the vicinity of the given feature being at least partially averaged out; and using a display, displaying the enhanced movie of the portion of the subject's body, by displaying, as a stream of image frames, the plurality of averaged image frames, wherein acquiring the plurality of image frames comprises acquiring, sequentially, first and second image frames of the portion of the subject's body, wherein generating the enhanced movie of the portion of the subject's body comprises: generating a first moving-average image frame, in which the vicinity of a given feature is enhanced, using frames of the portion of the subject's body that were acquired prior to the acquisition of the first and second acquired image frames; aligning the given feature in the first acquired image frame with the given feature in the first moving-average image frame; when the given feature in the first acquired image frame is aligned with the given feature in the first moving-average image frame, averaging the first acquired image frame with the first moving-average image frame to generate a second moving average image frame in which the vicinity of the given feature is enhanced; aligning the given feature in the second moving-average image frame with the given feature in the second acquired image frame; and when the given feature in the second moving-average image frame is aligned with the given feature in the second acquired image frame, averaging the second acquired image frame with the second moving-average image frame to generate a third moving-average image frame in which the vicinity of the given feature is enhanced, and wherein displaying the enhanced movie of the portion of the subject's body comprises displaying, in an image stream, the first, second, and third moving-average image frames.