Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
134 words
A television standards converter for converting an input digital video signal from one television standard to another, the standards converter comprising: a high-pass filter for filtering said input video signal horizontally and vertically; a plurality of parallel processing channels comprising respective means for determining, pixel by pixel of the high-pass filtered video signal, motion vector magnitudes and correlation magnitudes for a range of horizontal and vertical pixel offsets; respective low-pass filters for filtering said correlation magnitudes; means for determining for each pixel of said video signal, from the relationship between the respective motion vector magnitude and correlation magnitude, a motion vector corresponding to the maximum correlation magnitude; and a temporal interpolator for deriving interpolated fields or frames by combining sample values offset by the motion vectors determined to correspond to the maximum correlation magnitudes.
Claim 2
Dependent Claim
134 words
A television standards converter for converting an input digital video signal from one television standard to another, the standards converter comprising: a high-pass filter for filtering said input video signal horizontally and vertically; a plurality of parallel processing channels comprising respective means for determining, pixel by pixel of the high-pass filtered video signal, motion vector magnitudes and correlation magnitudes for a range of horizontal and vertical pixel offsets; respective low-pass filters for filtering said correlation magnitudes; means for determining for each pixel of said video signal, from the relationship between the respective motion vector magnitude and correlation magnitude, a motion vector corresponding to the maximum correlation magnitude; and a temporal interpolator for deriving interpolated fields or frames by combining sample values offset by the motion vectors determined to correspond to the maximum correlation magnitudes.
Claim 3
Dependent Claim
79 words
A converter according to claim 1 wherein said maximum correlation magnitude is determined by applying scaling and threshold values to said motion vectors; locating the first positive and negative motion vector peaks; if the motion vector magnitude associated with these two peaks is less than a predetermined magnitude, interpolating intermediate samples either side of each of said two peaks; and checking the interpolated samples for a peak larger than said two peaks and, if found, selecting the larger peak.
Claim 4
Dependent Claim
17 words
A converter according to claim 1 wherein said high-pass filter and said low-pass filters are one-dimensional filters.
Claim 5
Dependent Claim
15 words
A converter according to claim 1 wherein said high-pass filter is a Hilbert type filter.
Claim 6
Dependent Claim
26 words
A converter according to claim 1 wherein in determining said motion vectors a scaling factor is applied progressively to attenuate motion vectors of relatively large value.
Claim 7
Dependent Claim
27 words
A converter according to claim 1 wherein in determining said motion vectors a threshold value proportional to the vector magnitude is substracted from each said motion vector.
Claim 8
Dependent Claim
17 words
A converter according to claim 1 wherein said high-pass filter and said low-pass filters are two-dimensional filters.
Claim 9
Dependent Claim
20 words
A converter according to claim 7 wherein said high-pass filter and said low-pass filter are symmetrical finite impulse response filters.
Claim 10
Dependent Claim
32 words
A converter according to claim 1 wherein said input video signal is converted from an interlaced digital video signal to a progressive scan digital video signal before derivation of said motion vectors.
Claim 11
Dependent Claim
123 words
A converter according to claim 9 further comprising: a second high-pass filter for filtering said input interlaced video signal; a second plurality of parallel processing channels comprising respective means for determining, pixel by pixel of the low-pass filtered interlaced video signal, gradient vector magnitudes and correlation magnitudes for a range of pixel offsets; respective second low-pass filters for filtering said correlation magnitudes; means for determining for each pixel of said interlaced video signal, from the relationship between the respective gradient vector magnitude and correlation magnitude, a gradient vector corresponding to the maximum correlation magnitude; and a spatial interpolator for deriving interpolated frames of said progressive scan video signal by combining sample values offset by the gradient vectors corresponding to the maximum correlation magnitudes.