Upsampling filter for a down conversion system

An apparatus for forming a third set of low resolution down-sampled predicted pixel values corresponding to a current frame of a video signal from a second set of low resolution pixel values corresponding to a residual image of the current frame of the video signal and from a first set of down-sampled low resolution pixel values corresponding to at least one reference frame of the video signal, the apparatus comprising:

• memory means for storing the first set of down-sampled low resolution pixel values;
• up-sampling means for receiving the first set of down-sampled low resolution reference pixel values from the memory means and using Lagrangian interpolation to convert the first set of down-sampled low resolution pixel values into a set of up-sampled low resolution pixel values corresponding to the at least one reference frame of the video signal;
• summing means for adding the second set of low resolution pixel values corresponding to the residual image of the current frame of the video signal to the set of up-sampled low resolution pixel values corresponding to the at least one reference frame of the video signal to form a set of low resolution predicted pixel values corresponding to the current frame of the video signal;
• and
• decimating means for deleting selected ones of the set of low resolution pixel values corresponding to the current frame of the video signal to generate the third set of low resolution down-sampled predicted pixel values corresponding to the current frame of the video signal for storage in the memory means as farther reference pixel values to be used to generate further predicted frames of video signals in a sequence of predicted frames;
• wherein the sequence of predicted frames of video signals generated using the Lagrangian interpolation exhibits substantially uniform motion racking.