An adaptive pre-processing technique is provided to reduce perceptually
unimportant information in a frame (such as some of the high frequency
information) so as to optimize compression efficiency and to maximize
perceived video quality of a compressed video sequence for a given bit
rate. This pre-processing includes a combination of performing
pre-filtering of video data to remove high frequency components and to
smooth out high frequency texture information within object boundaries,
based at least in part on human visual system characteristics. The
technique is adaptive in that feedback regarding the current state of the
encoder is used to change the filtering strength or region of support for
subsequent frames, as needed, in order to maintain the bit budget while
still generating visually acceptable video quality.