1. A video processing apparatus for enhancing presentation characteristics of a raster-scanned image signal, comprising: processing means responsive to an input signal representative of a raster-scanned image and to a statistical signal representative of a statistical value of said input signal for combining said input signal and said statistical signal to produce an output signal representing an enhancement of said raster-scanned image by increasing the contrast in the image; plural-order filter means responsive to said input signal and to a filter variable signal for producing said statistical signal during a first image raster field defined by said input signal, said statistical signal produced by two-dimensional filtration of said input signal within a horizontal filter bandwidth and a vertical filter bandwidth, at least one of said filter bandwidths being determined by said filter variable signal; and phase adjustment means coupled between said processing means and said plural-order filter means for adjusting the phase of said statistical signal to substantially equal the phase of said input signal by producing said filter variable signal based upon two-dimensional filtration of a second image raster field defined by said input signal, said second image raster field corresponding to, but preceding, said first image raster field.