In a global motion estimation, profiles (Prof1, Prof2, ProO, Prof4) are determined of frames (FR1, FR2, FR3, FR4) of an input video signal. Each profile comprises a value, for each pixel in a first direction of the frame, which is obtained by combining pixels in a second direction of the frame. The profiles are updated (Upd Prof) with a first shift (Δx′12, Δx′2, Δx′34) to obtain updated profiles (Prof1′, Prof2′, Pro3′), and the updated profiles are matched (S/M) to obtain a secondary shift (Δx′12, Δx′23). Preferably, the first shift is a zero shift. The updating may be effected by shifting one of the profiles over the first shift to obtain a shifted profile, and subtracting another one of the profiles from the shifted profile. If the second direction is the vertical direction, the profile may comprise a vertically combined (e.g. averaged) pixel value for each pixel in the horizontal direction.