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US 2002/0163587 A1Published application
Image pickup apparatus, exposure decision method, program, and storage medium
AssigneeCanon Kabushiki Kaisha
InventorKenji Takahashi
Life of this patent
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Abstract
The object of this invention is to increase the precision of an exposure value in a scan AE scheme. To achieve this object, an image is picked at a plurality of exposure values. Screen-split brightness values and exposure value differences are obtained for the respective exposure values. Two screen-split brightness values and exposure value differences are selected from the relationship between the exposure value differences. A brightness value is calculated from the selected values to decide an exposure value in actual exposure.
Claims10
An image pickup apparatus comprising:
- an image pickup device that picks up an object;
- and
- a processing device having a brightness value calculation unit that obtains brightness values of an image at respective exposure values from a plurality of image data obtained by picking up an image by said image pickup device at a plurality of different exposure values, an exposure difference value calculation unit that calculates exposure difference values representing differences between the brightness values and a preset target brightness value in actual exposure, and an exposure value calculation unit that calculates an exposure value in actual exposure on the basis of at least two image data out of the plurality of image data in accordance with calculation results of said exposure difference value calculation unit.
An exposure decision method comprising:
- the brightness value calculation step of obtaining brightness values of an image at respective exposure values from a plurality of image data obtained by picking up an image at a plurality of different exposure values;
- the exposure difference value calculation step of calculating exposure difference values representing differences between the brightness values and a preset target brightness value in actual exposure;
- and
- the exposure value calculation step of calculating an exposure value in actual exposure on the basis of at least two image data out of the plurality of image data in accordance with calculation results in the exposure difference value calculation step.
1 more element
Dependencies are inferred from the claim text.