A portion of an image, belonging to a current encoding unit, is encoded by motion compensation with respect to a reference image portion indicated by an item of motion information. A motion information predictor is selected from among a set of motion information predictors and the item of motion information is encoded with respect to said motion information predictor. The set of motion information predictors used is permitted to include at least one temporal motion information predictor associated with an image portion of a previous image of said sequence but is not permitted to include any spatial motion information predictor that is unobtainable from encoded data of said current encoding unit, for example a spatial motion information predictor that was itself encoded with respect to a temporal motion information predictor.