Image sensing method and apparatus for producing a color video signal and luminance video signal
AssigneeCanon Kabushiki Kaisha
InventorTeruo Hieda
Life of this patent
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Abstract
An image sensing apparatus having a small amount of circuitry and exhibiting little power consumption is characterized in that a required delay line is connected into the circuitry at a point after a gamma-corrector in a digital signal processing system that processes an intensity signal, and another required delay line is connected into the circuitry at a point after a limiter in a corrective-signal generating system, which is for generating a signal that corrects a color signal. As a result, the delay lines are provided in fewer stages and need only have a small bit width. This makes it possible to reduce the amount of circuitry as well as power consumption.
Claims8
An image sensing apparatus for producing a color video signal by subjecting an output video signal from a color image sensing element to digital signal processing, comprising:
- intensity-signal extracting means for extracting an intensity signal from a digital video signal, which is an analog to digital signal converted from the output video signal from the color image sensing element;
- limiting means for limiting an amplitude of the intensity signal;
- color-difference signal extracting means for extracting color-difference signals from the digital video signals:
- synchronization means for synchronizing said intensity signal limited by said limiting means with said color-difference signals extracted by said color difference signal extracting means;
- gain control means for controlling the color-difference signals based upon said synchronized intensity signal;
- and
- video signal producing means for producing a color video signal by cutting predetermined high-frequency components from said color-difference signals controlled by said gain control means into a color video signal.
An image sensing apparatus for producing a luminance video signal by subjecting an output video signal from a color image sensing element to digital signal processing, comprising:
- analog-to-digital converting means for converting the output video signal of the color image sensing element into a digital video signal;
- intensity-signal extracting means for extracting an intensity signal from a digital video signal, which is a signal analog-to-digital converted from the output video signal from the color image sensing element;
- color-difference signal extracting means for extracting color-difference signals from the digital video signal;
- gain control means for controlling the gain of the color difference signals;
- gamma-correcting means for gamma-correcting the intensity signal;
- synchronization means for synchronizing said intensity signal gamma-corrected by said gamma-correcting means with said color-difference signals gain-controlled by said gain control means;
- and
- luminance video signal producing means for correcting said intensity signal synchronized by said synchronization means based upon said color-difference signals gain-controlled by said gain control means, and producing a luminance video signal based upon said corrected intensity signal and a blanking signal.
An image sensing method for producing a color video signal by subjecting an output video signal from a color image sensing element to digital signal processing, comprising:
- an intensity-signal extracting step of extracting an intensity signal from a digital video signal, which is analog-to-digital signal converted from the output video signal from the color image sensing element;
- a limiting step of limiting an amplitude of the intensity signal;
- a color-difference signal extracting step of extracting color-difference signals from the digital video signals;
- a synchronization step of synchronizing said intensity signal limited by said limiting step with said color-difference signals extracted by said color-difference signal extracting step;
- a gain control step of controlling the color-difference signals based upon said synchronized intensity signal:
- a video-signal producing step of producing a color video signal by cutting predetermined high-frequency components from said color difference signals controlled by said gain control step, into a color video signal.
An image sensing method for producing a luminance video signal by subjecting an output video signal from a color image sensing element to digital signal processing, comprising:
- an analog-to-digital converting step of converting the output video signal of the color image sensing element into a digital video signal;
- an intensity-signal extracting step of extracting an intensity signal from digital video signal, which is a signal analog-to-digital convened from the output video signal from the color image sensing element;
- a color-difference signal extracting step of extracting color-difference signals from the digital video signal;
- a gain control step of controlling the gain of the color-difference signals;
- a gamma-correcting step of gamma-correcting the intensity signal;
- a synchronization step of synchronizing said intensity signal gamma-corrected by said gamma-correcting step with said color-difference signals gain-controlled by said gain control step;
- and
- a luminance video signal producing step of correcting said intensity signal synchronized by said synchronization step based upon said color-difference signals gain-controlled by said gain-control step, and producing a luminance video signal based upon said corrected intensity signal and a blanking signal.
Dependencies are inferred from the claim text.