Video signal processing apparatus for reducing aliasing interference

A video signal processing apparatus for reducing aliasing interference comprising:

• an interpolating means which receives a high definition television signal which has been bandwidth-compressed by offset sub-sampling for interpolating a non-sample point from intra-field sample points to a sub-sampled signal;
• a first memory means for delaying a signal thus interpolated for one field period;
• a second memory means for delaying an output signal of said first memory means for a further one field period;
• a first adder means for performing an inter-field averaging process from an input signal of said first memory means and an output signal of said second memory means;
• a second adder means for performing an inter-frame averaging process from an input signal of said first memory means and an output signal of said second memory means;
• a correlation discriminating means for detecting one field difference and one frame difference from input and output signals of said first and second memory means and for outputting a switching signal in accordance with magnitudes of the difference thus detected;
• and
• signal switching means for switching an output signal of said first adder means and an output signal of said second adder means in accordance with the switching signal from said correlation discriminating means.

A video signal processing apparatus for reducing aliasing interference comprising:

• a first memory means for delaying a high definition television signal which has been bandwidth-compressed by offset sub-sampling for one field period;
• a second memory means for delaying an output signal of said first memory means for a further one field period;
• first, second and third interpolating means for interpolating non-sampling points from intra-field sample points of a sub-sampled signal in accordance with input and output signals of said first and second memory means;
• a first adder means for performing an inter-field averaging process from an output signal of said first interpolating means and an output signal of said second interpolating means;
• a second adder means for performing an inter-frame averaging process from an output signal of said first interpolating means and an output signal of said third interpolating means;
• a correlation discriminating means for detecting one field difference and one frame difference from output signals of said first, second and third interpolating means and for outputting a switching signal in accordance with magnitudes of differences thus detected;
• and
• a signal switching means for switching an output signal of said first adder means and an output signal of said second adder means in accordance with the switching signal from said correlation discriminating means.

A video signal processing apparatus for reducing aliasing interference comprising:

• an interpolating means which receives a high definition television signal which has been bandwidth-compressed by offset sub-sampling for interpolating a non-sample point from intra-field sample points of a sub-sampled signal;
• a first memory means for delaying a signal thus interpolated for one field period;
• a second memory means for delaying an output signal of said first memory means for a further one field period;
• a median-value signal selection means for extracting a median-value signal of three adjacent inter-field signals from input and output signals of said first and second adder means;
• a first adder means for averaging an output signal of said first adder means and an output signal of said median-value signal selection means;
• a second adder means for performing an inter-frame averaging process from an input signal of said first memory means and an output signal of said second memory means;
• a correlation discriminating means for detecting one field difference and one frame difference from input and output signals of said first and second memory means and for outputting a switching signal in accordance with magnitudes of differences thus detected;
• and a signal switching means for switching an output signal of said first adder means an output signal of said second adder means in accordance with the switching signal from said correlation discriminating means.

A video signal processing apparatus for reducing aliasing interference comprising:

• a first memory means for delaying a high definition television signal which has been bandwidth-compressed by offset sub-sampling for one field period;
• a second memory means for delaying an output signal of said first memory means for a further one field period;
• a first, second and third interpolating means for interpolating non-sample points from intra-field sample points of a sub-sampled signal in accordance with input and output signals of said first and second memory means;
• a median-value signal selection means for extracting a median-value signal of three adjacent inter-field signals from output signals of said first, second and third interpolating means;
• a first adder means for averaging an output signal of said second interpolating means and an output signal of said median-value signal selection means;
• a second adder means for performing an inter-frame averaging process from an output signal of said first interpolating means and an output signal of said third interpolating means;
• a correlation discriminating means for detecting one field difference and one frame difference from output signals of said first, second and third interpolating circuits and for outputting a switching signal in accordance with the magnitudes of differences thus detected;
• and
• a signal switching means for switching an output signal of said adder means and an output signal of said second adder means in accordance with the switching signal from said correlation discriminating means.