Camera capable of canceling noise in image data and signal processing method thereof
AssigneeCasio Computer Co., Ltd.
InventorsHiroyuki Nakata, Noriysau Murata
Life of this patent
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Abstract
In a camera having a gamma-correction circuit on an output signal processing path of a CCD, an incident light path leading to the CCD is kept opening in a state where nonlinear gamma-correction processing in the gamma-correction processing circuit is prohibited, first image data (CCD output data; DATA1) are generated based on electric signal output from the CCD, incident light path leading to the CCD is kept closing, second image data (CCD output data; DATA2) are generated based on electric signal output from the CCD and lastly, the second image data DATA2 are subtracted from the first image data DATA1, thereby correcting to eliminate dark voltage component included in the first image data DATA1.
Claims19
A camera comprising:
- image pick-up means for outputting image data in accordance with incident light;
- first pick-up control means for obtaining first image data output from the image pick-up means under a condition where an incident light path of the image pick-up means is opened;
- second pick-up control means for obtaining second image data output from the image pick-up means under a condition where the incident light path of the image pick-up means is closed;
- means for correcting the first image data obtained by the first pick-up control means based on the second image data obtained by the second pick-up control means;
- first nonlinear processing means for subjecting the image data output from the image pick-up means to nonlinear processing;
- and
- means for prohibiting the nonlinear processing for the image data by said first nonlinear processing means when the first and second image data are obtained by the first and second pick-up control means, wherein said first pick-up control means and said second pick-up control means obtain the fist image data and the second image data which are not subjected to the nonlinear processing by said first nonlinear processing means.
A camera comprising:
- image pick-up means for outputting image data in accordance with incident light;
- first pick-up control means for obtaining first image data output from the image pick-up means under a condition where an incident light path of the image pick-up means is opened;
- second pick-up control means for obtaining second image data output from the image pick-up means under a condition where the incident light path of the image pick-up means is closed;
- means for determining whether a level of the first image data obtained by the first pick-up control means is saturated;
- and
- means for correcting the first image data obtained by the first pick-up control means based on a result of determination made by the determining means and based on the second image data obtained by the second pick-up control means.
A camera comprising:
- an image sensor which outputs image data in accordance with incident light;
- first pick-up control means for obtaining first image data output from the image sensor under a condition where an incident light path of the image sensor is opened;
- second pick-up control means for obtaining second image data output from the image sensor under a condition where the incident light path of the image sensor is closed;
- means for correcting the first image data obtained by the first pick-up control means based on the second image data obtained by the second pick-up control means;
- a gamma-correction circuit which non-linearly corrects a gamma characteristic of the image data output from the image sensor;
- and
- means for prohibiting the gamma characteristic correction for the image data by said gamma-correction circuit when the first and second image data are obtained by the first and second pick-up control means, wherein said first pick-up control means and said second pick-up control means obtain the fist image data and the second image data which are not subjected to the gamma characteristic correction.
A signal processing method for a camera which carries out nonlinear processing for image data output from an image sensor, comprising steps of:
- prohibiting the nonlinear processing for the image data output from the image sensor under a condition where an incident light path of the image sensor is opened, thereby obtaining first image data which are not subjected to the nonlinear processing;
- step of prohibiting the nonlinear processing for the image data output from the image sensor under a condition where the incident light path of the image sensor is closed, thereby obtaining second image data which are not subjected to the nonlinear processing;
- and
- correcting the first image data based on the second image data.
A signal processing method for a camera, comprising steps of:
- obtaining first image data output from an image sensor under a condition where an incident light path of the image sensor is opened;
- obtaining second image data output from an image sensor under a condition where an incident light path of the image sensor is closed;
- determining whether a level of the first image data is saturated;
- and
- correcting the first image data based on a result of the determination and the second image data.
Dependencies are inferred from the claim text.