  In this paper, a framework of video face replacement is proposed and it deals
with the flicker of swapped face in video sequence. This framework contains two
main innovations: 1) the technique of image registration is exploited to align
the source and target video faces for eliminating the flicker or jitter of the
segmented video face sequence; 2) a fast subpixel image registration method is
proposed for farther accuracy and efficiency. Unlike the priori works, it
minimizes the overlapping region and takes spatiotemporal coherence into
account. Flicker in resulted videos is usually caused by the frequently changed
bound of the blending target face and unregistered faces between and along
video sequences. The subpixel image registration method is proposed to solve
the flicker problem. During the alignment process, integer pixel registration
is formulated by maximizing the similarity of images with down sampling
strategy speeding up the process and sub-pixel image registration is a
single-step image match via analytic method. Experimental results show the
proposed algorithm reduces the computation time and gets a high accuracy when
conducting experiments on different data sets.
