1. A method of communicating an image sequence rendered by a host computer, the method comprising: determining, by the host computer and after performing a progressive encoding of a constant image at a constant spatial location in the image sequence, a lossless motion of the constant image in the image sequence, wherein the progressive encoding comprises generating, in absence of a lossless match of the constant image to a previous image, a lossy encoded state of the constant image comprising a lossy encoding of a frequency transform of the constant image and a first refinement encoding of the frequency transform, wherein determining the lossless motion comprises detecting the constant image at a new spatial location in the image sequence, wherein the constant image comprises exact pixel value matches between frames of a period of the constant image; generating, by the host computer, a lossless motion vector as an encoding of the lossless motion; communicating, from the host computer to a remote computer, the lossy encoding, the first refinement encoding, and the lossless motion vector; determining, subsequent to communicating the lossless motion vector, persistence of the constant image at the new spatial location; and communicating, to the remote computer, a lossless re-encoding of the constant image at the new spatial location in response to the persistence and the lossy encoded state.