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US 6,788,339 B1Granted
Image pickup apparatus
AssigneeCanon Kabushiki Kaisha
InventorEiichiro Ikeda
Life of this patent
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Abstract
An image pickup apparatus is capable of accurately performing white balance control by accurately detecting color temperature without depending on a luminance signal level. In the image pickup apparatus, a color evaluation value is obtained by computation from color signals coming from a plurality of pixels of an image sensor having complementary color filters. It is determined whether the color evaluation value is included within a white determining range. The white determining range is made to vary according to the shooting condition and/or the object condition. The white balance is adjusted on the basis of color signals having color evaluation values included within the white determining range.
Claims35
An image pickup apparatus comprising:
- an image sensor;
- and
- a white balance adjusting device adapted to evaluate a color signal outputted from said image sensor in a value,
- determine whether or not the value of the evaluated color signal is included within a white determining range to regard the color signal corresponding to the included value as white,
- and adjust white balance on the basis of control signal obtained from the color signal corresponding to the value determined to be included in the changed white determining range,
- wherein said white balance adjusting device changes an area of the white determining range smaller as the brightness of a field increases.
3 more elements
An image pickup apparatus comprising:
- an image sensor;
- and
- a white balance adjusting device adapted to perform a first evaluation of a color signal outputted from said image sensor, to perform a first determination of whether or not each value of a first color signal evaluated by the first evaluation is included within a white determining range, and to perform a second determination to determine whether or not each value of averaged color signals, respectively, obtained by averaging color signals in a divided area of one picture and evaluated by a second evaluation is included within the white determining range,
- wherein said white balance adjusting device obtains a first control signal on the basis of the values determined to be included within the white determining range by the first determination, obtains a second control signal on the basis of the values determined to be included within the white determining range by the second determination, obtains a third control signal from the first and second control signals according to a ratio of the number of sample points of the first color signal determined to be included within the white determining range, and the number of sample points of the first color signal not included within the white determining range by the first determination, and adjusts the white balance on the basis of the third control signal.
1 more element
An image pickup apparatus comprising:
- an image sensor;
- and
- a white balance adjusting device adapted to evaluate a color signal outputted from said image sensor and, perform a weighted correction of each value of the evaluated color signals corresponding to each white determining range to determine whether or not each value is available to adjust white balance and to adjust white balance on the basis of the corrected values,
- wherein said white balance adjusting device decreases a weighted-correction coefficient to the color signals according to increasing brightness of a field.
1 more element
An image pickup apparatus comprising:
- an image sensor;
- and
- a white balance adjusting device adapted to evaluate a color signal outputted from said image sensor in a value,
- determine whether or not each value of the evaluated color signal is included within a white determining range to regard the color signal corresponding to the included value as white,
- and adjust white balance on the basis of control signal obtained from the color signal corresponding to the value determined to be included within the changed white determining range,
- wherein said white balance adjusting device changes an area of the white determining range larger as a degrees of effect of flash light to an external light decreases.
3 more elements
An image processing method for processing an image sensed by an image sensor comprising the steps of:
- evaluating a color signal outputted from said image sensor in value;
- determining whether or not a the value of the evaluated color signal is included within a white determining range to regard the color signal corresponding to the included value as white;
- changing an area of the white determining range smaller as a brightness of a field increases;
- and
- adjusting white balance on the basis of control signal obtained from the color signal corresponding to the value determined to be included within the changed white determining range.
2 more elements
An image processing method for processing an image sensed by an image sensor comprising the steps of:
- evaluating a color signal outputted from said image sensor;
- determining whether or not each value of the evaluated color signal is included within a white determining range to regard the color signal corresponding the included value as white;
- changing an area of the white determining range larger as a degrees of effect of flash light to an external light decreases;
- and
- adjusting white balance on the basis of control signal obtained from the color signal corresponding to the value determined to be included within the changed white determining range.
2 more elements
An image processing method for processing an image sensed by an image sensor comprising the steps of:
- performing a first determination whether or not each value of color signals evaluated by a first evaluation is included within a white determining range;
- performing a second determination to determine whether or not each value of averaged color signals, respectively, obtained by averaging color signals in a divided area of one picture and evaluated by a second evaluation is included within said white determining range;
- obtaining a first control signal on the basis of the values determined to be included within said white determining range by said first determination;
- obtaining a second control signal on the basis of the values determined to be included within said white determining range by said second determination;
- obtaining a third control signal from the first and the second control signals according to a ratio of the number of sample points of the first color signal determined to be included within the white determining range and the number of sample points of the first color signal not included within the white determining range by the first determination;
- and
- adjusting white balance on the basis of the third control signal.
4 more elements
An image processing method for processing an image sensed by an image sensor comprising the steps of:
- evaluating color signals outputted from said image sensor;
- performing weighted correction of each value of the evaluated color signals corresponding to each white determining range to determine whether or not each value is available to adjust white balance;
- and
- adjusting the white balance on the basis of the corrected values,
- wherein a weighted-correction coefficient to the color signals is decreased according to increasing brightness of a field.
2 more elements
An image pickup apparatus comprising:
- an image pickup device to produce color signals;
- a white balance adjusting device adapted to adjust gains of said color signals according to a predetermined range of white component of said color signals,
- wherein said predetermined range varies according to the brightness of the object and is made smaller when the brightness of the object increases.
An image processing apparatus comprising:
- an inputting device for inputting color signal;
- a white detecting circuit for detecting white portion in a field, having a white detecting range to regard an output color signal from said inputting device as a white;
- wherein said white detecting range is changed smaller when a brightness of the field is over a predetermined value.
An image processing method for processing an image picked up by an image sensor comprising:
- inputting a color signal;
- detecting white portion in a field, having a white detecting range to regard an output color signal from said inputting device as white;
- wherein said white detecting range is changed smaller when a brightness of the field is over a predetermined value.
Dependencies are inferred from the claim text.