A method of detecting the reliability of a field of movement vectors of one image in a sequence of video images. The method includes a stage of calculating a stability parameter, Det_Stab(t), for the field. The parameter is based on a comparison (4), over two successive images, of the number of occurrences of the majority vectors of the movement-vectors fields of each of these images. A field is defined as stable if the variation in the number of occurrences lies within a predefined bracket. Reliability (7) is decided on the basis of this stability parameter.
A motion compensation deinterlacer for producing a progressive scan signal from an interlaced signal includes a motion compensation unit that derives missing lines in an interlaced field from at least one other field in the interlaced signal. The deinterlacer includes a device that derives a first confidence measure for the accuracy of the motion compensation unit using known lines of the field for which missing lines are to be derived. Another device derives a second confidence measure for the accuracy of the motion compensation unit using known lines of at least two other fields. The first and second confidence measures are combined. An output unit selects outputs for display from at least the motion compensation unit and one other deinterlacing device in dependence on the combined confidence measures.
