1. A method of estimating jitter between two video frames in a digital video sequence, comprising: comparing a pixel subset of one video frame to candidate pixel subsets within a search area in the other video frame to determine a preliminary matching pixel subset from the candidate pixel subsets; determining an actual matching pixel subset from the other video frame based on the location of the preliminary matching pixel subset relative to said search area; and calculating a global jitter vector based on the pixel subset and the actual matching pixel subset thereby to estimate the jitter.