1. A method ( 100 ) for processing video data comprising a plurality of images, the plurality of images having an earlier and later frame of a video sequence, having a label for at least a first region or patch in the earlier and at least a second region or patch in the later frame, the method ( 100 ) comprising: obtaining a model of the plurality of images, and using the model to propagate the label of the first and/or second region or patch to at least one other image of the sequence, the propagating being by a probabilistic method for estimating the label in the other image by a directed graphical method.