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US 2013/0258175 A1Published application
Image sensing apparatus, exposure control method and recording medium
AssigneeCanon Kabushiki Kaisha
InventorToshifumi Osawa
Life of this patent
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Abstract
An image sensing apparatus obtains the weighted average luminance of an image sensing target that puts weight on a main subject in an obtained luminance distribution of the image sensing target. The image sensing apparatus decides exposure control values based on the average luminance of a region that is lower than the weighted average luminance, out of regions each of a predetermined size contained in the image sensing target, and the weighted average luminance.
Claims20
An image sensing apparatus comprising:
- an obtaining unit configured to obtain information about a luminance distribution of an image sensing target;
- a weighted average unit configured to obtain a weighted average luminance of the image sensing target, that puts weight on a main subject, from the information about the luminance distribution of the image sensing target obtained by said obtaining unit;
- and
- a decision unit configured to decide an exposure control value based on an average luminance of a region that is lower than the weighted average luminance, out of regions each of a predetermined size contained in the image sensing target, and the weighted average luminance.
1 more element
An image sensing apparatus comprising:
- an obtaining unit configured to obtain information about a luminance distribution of an image sensing target;
- a first calculation unit configured to calculate a first average luminance value by performing weighting computation using a larger weight for a region of interest than a weight for another region in the luminance distribution of the image sensing target obtained by said obtaining unit;
- a second calculation unit configured to calculate an average luminance value of a region which is larger than the region of interest and smaller than a region used in the weighting computation;
- and
- a decision unit configured to decide an exposure control value based on a difference between a second average luminance value which is calculated by said second calculation unit and is smaller than the first average luminance value, and the first average luminance value.
2 more elements
An exposure control method comprising:
- a photometry step of causing a photometry unit to obtain a luminance distribution of an image sensing target;
- a weighted average step of causing a weighted average unit to obtain a weighted average luminance of the image sensing target that puts weight on a main subject in the luminance distribution of the image sensing target obtained in the photometry step;
- and
- a decision step of deciding an exposure control value based on an average luminance of a region that is lower than the weighted average luminance, out of regions each of a predetermined size contained in the image sensing target, and the weighted average luminance.
1 more element
An exposure control method comprising:
- an obtaining step of causing an obtaining unit to obtain information about a luminance distribution of an image sensing target;
- a first calculation step of causing a computation unit to calculate a first average luminance value by performing weighting computation using a larger weight for a region of interest than a weight for another region in the luminance distribution of the image sensing target obtained in the obtaining step;
- a second calculation step of calculating an average luminance value of a region which is larger than the region of interest and smaller than a region used in the weighting computation;
- and
- a decision step of deciding an exposure control value based on a difference between a second average luminance value which is calculated in the second calculation step and is smaller than the first average luminance value, and the first average luminance value.
2 more elements
Dependencies are inferred from the claim text.