Automatic focusing device employing a frequency domain representation of a digital video signal
First Claim
1. An automatic focusing device comprising:
- an A/D converter for converting a supplied video signal to a digital signal;
orthogonal conversion means for converting the digital signal from the A/D converter to a two-dimensional frequency domain representation;
control means for producing a focusing control output based on a plurality of frequency components included in the two-dimensional frequency domain representation; and
a focusing circuit responsive to the focusing control output for performing a focusing operation such that all of said plurality of frequency components are maximized.
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Abstract
An automatic focusing device has an A/D converter for converting a supplied video signal to a digital signal; an orthogonal converter for converting a video signal transmitted from the A/D converter to a signal indicative of a frequency component region; and a control section for producing a control signal for performing a focusing operation based on information of the frequency component transmitted from the orthogonal converter. The orthogonal converter performs a discrete cosine transformation with respect to the digitally converted video signal. The orthogonal converter transmits low to high frequency components from the digitally converted video signal. The control section transmits the control signal for performing a focusing operation based on an arbitrary component of the frequency components transmitted from the orthogonal converter. A circuit for performing the focusing operation may be constructed on the basis of a plurality of frequency components.
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Citations
6 Claims
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1. An automatic focusing device comprising:
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an A/D converter for converting a supplied video signal to a digital signal; orthogonal conversion means for converting the digital signal from the A/D converter to a two-dimensional frequency domain representation; control means for producing a focusing control output based on a plurality of frequency components included in the two-dimensional frequency domain representation; and a focusing circuit responsive to the focusing control output for performing a focusing operation such that all of said plurality of frequency components are maximized. - View Dependent Claims (2, 3, 4, 5, 6)
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Specification