1. A halo-reducing frame rate converter comprising: a forward motion vector generator, receiving a current frame of graphics data and a next frame of graphics data, and generating forward motion vectors for the current frame, the forward motion vectors each pointing to a best-matching block in the next frame; a backward motion vector generator, receiving the current frame of graphics data and generating backward motion vectors, the backward motion vectors each pointing to a best matching block in an earlier frame in a sequence of frames; wherein the forward motion vectors each have a block-matching error to the best-matching block in the next frame; wherein the backward motion vectors each have a block-matching error to the best-matching block in the earlier frame; a hybrid direction motion vector generator, receiving the forward motion vectors for the current frame, and receiving backward motion vectors for the current frame, the hybrid direction motion vector generator generating hybrid direction motion vectors for the current frame that include the forward motion vectors and the backward motion vectors, wherein forward motion vectors having block-matching errors above a threshold are deleted from the hybrid direction motion vectors for the current frame, wherein backward motion vectors having block-matching errors above the threshold are deleted from the hybrid direction motion vectors for the current frame; a covered region detector that projects a forward trajectory for each forward motion vector in the hybrid direction motion vectors for a prior frame, and that projects a backward trajectory for each backward motion vector in the hybrid direction motion vectors for the current frame, the covered region detector indicating a covered region in an interpolated frame between the prior frame and the current frame, wherein the covered region has at least one forward trajectory but not any backward trajectory intersecting the covered region; an interpolated motion vector refiner, that generates refined motion vectors for the interpolated frame by bi-directional motion estimation using the hybrid direction motion vectors for the prior frame and for the current frame; wherein the refined motion vectors include faulty motion vectors in the covered region; and a motion vector corrector that assigns hybrid direction motion vectors from the prior frame to replace the faulty motion vectors in the covered region detected by the covered region detector to generate corrected motion vectors for the interpolated frame, whereby faulty motion vectors in the covered region are replaced by hybrid direction motion vectors from an original frame after the covered region is detected by intersection of least one forward trajectory but not any backward trajectory.