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US 4,393,407 AGranted
Contour correcting apparatus for video signals
AssigneeCanon Kabushiki Kaisha
InventorYoshikazu Yokomizo
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Abstract
A contour correcting arrangement for video signals includes a differentiator to differentiate an input video signal, a delay circuit which delays by a predetermined time period the differentiated waveform resultant from the differentiation and the video signal, and a combining circuit for combining the inverted waveform of the differentiated waveform, delayed differentiated waveform, and delayed video signal.
Claims35
A contour correcting apparatus for video signals, comprising:
- differentiating means for differentiating an input video signal to produce a differentiated waveform;
- delay means for delaying said differentiated waveform and said video signal for a predetermined time period to produce a delayed differentiated waveform and delayed video signal;
- inverting means for phase inverting said differentiated waveform to produce a phase inverted differentiated waveform;
- and
- combining means for combining said phase inverted differentiated waveform, said delayed differentiated waveform and said delayed video signal.
2 more elements
A contour correcting apparatus for video signals, comprising:
- a differentiating circuit for performing primary differentiation of an input video signal;
- an adder for adding an output of said differentiating circuit to said video signal;
- a delay circuit for delaying an output of said adder by a predetermined time period;
- and
- a combining circuit for combining said output of said differentiating circuit and said output of said delay circuit.
2 more elements
A contour correcting apparatus for video signals, comprising:
- video signal generating means for generating a video signal;
- differentiating means for effecting primary differentiation of said video signal to produce a primary differentiated waveform;
- and
- combining means for combining said video signal and said primary differentiated waveform so that a changing portion of said video signal is emphasized.
1 more element
A contour correcting apparatus for video signals, comprising:
- video signal generating means for generating a video signal;
- signal forming means for forming a plurality of change signals which differ from each other in phase and with each change signal being responsive to a change of said video signal;
- amplitude varying means for producing a plurality of amplitude-modified change signals corresponding to said plurality of change signals, with each amplitude-modified change signal differing in amplitude from a corresponding change signal;
- and
- combining means for combining said video signal and said amplitude-modified change signals in such a way that said amplitude-modified change signals do not cancel each other.
2 more elements
A contour correcting apparatus for video signals, comprising:
- video signal generating means for generating a video signal;
- signal forming means for forming a change signal indicating the degree of change of said video signal and having duration varying means for varying the duration of said change signal, said duration varying means including differentiating means for differentiating said video signal to produce a differentiated waveform wherein said differentiating means comprises a differentiating circuit constructed and arranged to effect a time constant T which satisfies the following relationship with respect to the maximum frequency component f.sub.max of said video signal:
- 1/(5.times.f.sub.max).gtoreq.T.gtoreq.1/(10.times.f.sub.max)
- amplitude varying means for producing an amplitude-modified change signal which differs in amplitude from said change signal;
- and
- combining means for combining said amplitude-modified change signal and said video signal.
3 more elements
A contour correcting apparatus for video signals, comprising:
- video signal generating means for generating a video signal;
- signal forming means for forming a change signal indicating the degree of change of said video signal;
- amplitude varying means for producing an amplitude-modified change signal which differs in amplitude from said change signal;
- combining means for combining said amplitude-modified change signal and said video signal to produce a combined signal;
- and
- delay means for producing a signal delayed by a determined time period from said combined signal.
3 more elements
A contour correcting apparatus for video signals, comprising:
- video signal generating means for generating a video signal;
- signal forming means for forming a change signal indicating the degree of change of said video signal;
- amplitude varying means for producing an amplitude-modified change signal which differs in amplitude from said change signal;
- combining means for combining said amplitude-modified change signal and said video signal to produce a combined signal;
- delay means for producing a signal delayed by a determined time period from said combined signal;
- and
- additional combining means for combining said amplitude-modified change signal and said delayed signal.
4 more elements
A contour correcting apparatus for video signals, comprising:
- video signal generating means for generating a video signal;
- differentiating means for differentiating said video signal to produce a differentiated waveform;
- combining means for combining said differentiated waveform and said video signal to produce a combined signal;
- forming means for forming a differentiated waveform which is phase inverted in comparison to said differentiated waveform produced by said differentiating means;
- and
- control means for controlling said combined signal in such a manner that, when said combined signal and said phase-inverted differentiated waveform are combined, said phase-inverted differentiated waveform and a differentiated waveform component in said combined signal do not act to cancel one another.
3 more elements
A contour correcting apparatus for video signals, comprising:
- video signal generating means for generating a video signal;
- signal forming means for forming a change signal indicating the degree of change in said video signal;
- delay means for delaying said video signal by a determined time period;
- and
- combining means for combining said change signal and said delayed video signal so that a changing portion of said video signal is emphasized.
2 more elements
A contour correcting apparatus for video signals, comprising:
- video signal generating means for generating a video signal;
- signal forming means for forming a change signal indicating the degree of change in said video signal, wherein said signal forming means includes differentiating means for differentiating said video signal to produce a differentiated waveform;
- delay means for delaying said video signal by a determined time period;
- and
- combining means for combining said change signal and said delayed video signal, wherein said combining means includes inverting means for inverting the phase of said differentiated waveform.
2 more elements
A contour correcting apparatus for video signals, comprising:
- video signal generating means for generating a video signal;
- correction signal forming means for generating a first correction signal for correcting one time-wise portion of said video signal and a second correction signal for correcting another time-wise portion of said video signal;
- and
- correcting means for combining said video signal and said first correction signal in a delayed state with said second correction signal.
1 more element
Dependencies are inferred from the claim text.