Imaging control apparatus, imaging control method, and program
In one example, an imaging apparatus includes an exposure controller that performs exposure control on the basis of information of a region of interest detected from a captured image by a region-of-interest detector. The exposure controller performs different exposure control for different cases, such as whether the region of interest is detected from the captured image. It obtains an exposure correction value on the basis of the region-of-interest exposure target value before a time of region-of-interest lost, and then performs exposure control with the exposure control value obtained by correcting the set region exposure target value with the exposure correction value, in a predetermined period in which the region of interest is not detected continuously from the time of the region-of-interest lost in which the region of interest is not detected from the captured image.
1. An imaging control apparatus comprising:
an exposure control unit configured to perform exposure control on a basis of information of a region of interest detected from a captured image by a region-of-interest detection unit,
wherein the exposure control unit is configured to:
perform exposure control in which a region-of-interest exposure target value calculated on a basis of a region-of-interest photometric value obtained from a first photometric region including at least a region of interest in an input frame is set as an exposure control value, in a case where the region of interest is detected from the captured image;
perform exposure control in which a set region exposure target value calculated on a basis of a set region photometric value obtained from a second photometric region determined in advance in the input frame is set as the exposure control value, in a case where the region of interest is not detected from the captured image; and
obtain an exposure correction value on a basis of the region-of-interest exposure target value before a time of region-of-interest lost, and then perform exposure control with the exposure control value obtained by correcting the set region exposure target value with the exposure correction value, in a predetermined period in which the region of interest is not detected continuously from the time of the region-of-interest lost in which the region of interest is not detected from the captured image.
2. The imaging control apparatus according to claim 1 , wherein the exposure correction value is a value indicating a relationship between the set region exposure target value before the time of the region-of-interest lost and the region-of-interest exposure target value before the time of the region-of-interest lost.
3. The imaging control apparatus according to claim 2 , wherein in the predetermined period, the exposure control unit performs exposure control with the exposure correction value obtained so as to make a specific numerical relationship between the set region exposure target value and the set region exposure target value corrected with the exposure correction value equivalent to the specific numerical relationship between the set region exposure target value before the time of the region-of-interest lost and the region-of-interest exposure target value before the time of the region-of-interest lost.
4. The imaging control apparatus according to claim 2 , wherein the exposure correction value is a difference value between the set region exposure target value before the time of the region-of-interest lost and the region-of-interest exposure target value before the time of the region-of-interest lost.
5. The imaging control apparatus according to claim 1 , wherein in a case where regions of interest are detected respectively inside and outside a specific region in the captured image by the region-of-interest detection unit, the exposure control unit calculates the region-of-interest exposure target value used to calculate the exposure correction value on a basis of at least one of a size of a detected region of interest, a number of detected regions of interest, or a position of the detected region of interest.
6. The imaging control apparatus according to claim 5 , wherein in a case where the size of the region of interest detected outside the specific region is greater than a reference size, the exposure control unit uses the region-of-interest exposure target value calculated for the region of interest to calculate the exposure correction value, and in a case where the size of the region of interest detected outside the specific region is not greater than the reference size, the exposure control unit does not use the region-of-interest exposure target value calculated for the region of interest to calculate the exposure correction value.
7. The imaging control apparatus according to claim 6 , wherein the reference size is a size of the region of interest detected inside the specific region.
8. The imaging control apparatus according to claim 5 , wherein in a case where the number of detected regions of interest outside the specific region is greater than a threshold, the exposure control unit uses the region-of-interest exposure target value calculated for the region of interest detected outside the specific region to calculate the exposure correction value, and in a case where the number of detected regions of interest outside the specific region is not greater than the threshold, the exposure control unit does not use the region-of-interest exposure target value calculated for the region of interest detected outside the specific region to calculate the exposure correction value.
9. The imaging control apparatus according to claim 5 , wherein in a case where, as the region of interest detected outside the specific region, there is the region of interest within a certain distance from the region of interest detected inside the specific region, the exposure control unit uses the region-of-interest exposure target value calculated for the region of interest to calculate the exposure correction value, and in a case where there is not the region of interest within a certain distance from the region of interest detected inside the specific region, the exposure control unit does not use the region-of-interest exposure target value calculated for the region of interest detected outside the specific region to calculate the exposure correction value.
10. The imaging control apparatus according to claim 1 , wherein the exposure control unit changes the predetermined period on a basis of a size of the region of interest detected by the region-of-interest detection unit.
11. The imaging control apparatus according to claim 1 , wherein the exposure control unit changes the predetermined period on a basis of a number of regions of interest detected by the region-of-interest detection unit.
12. The imaging control apparatus according to claim 1 , wherein the exposure control unit changes the predetermined period on a basis of a number of times at which the region of interest is lost within a certain time.
13. The imaging control apparatus according to claim 1 , wherein the exposure control unit changes the predetermined period on a basis of determining a user operation.
14. An imaging control method for performing exposure control, the imaging control method comprising:
perform exposure control in which a region-of-interest exposure target value calculated on a basis of a region-of-interest photometric value obtained from a first photometric region including at least a region of interest in an input frame is set as an exposure control value, in a case where the region of interest is detected from a captured image;
perform exposure control in which a set region exposure target value calculated on a basis of a set region photometric value obtained from a second photometric region determined in advance in the input frame is set as the exposure control value, in a case where the region of interest is not detected from the captured image; and
obtain an exposure correction value on a basis of the region-of-interest exposure target value before a time of region-of-interest lost, and then perform exposure control with the exposure control value obtained by correcting the set region exposure target value with the exposure correction value, in a predetermined period in which the region of interest is not detected continuously from the time of the region-of-interest lost in which the region of interest is not detected from the captured image.
15. The imaging control method according to claim 14 , wherein the exposure correction value is a value indicating a relationship between the set region exposure target value before the time of the region-of-interest lost and the region-of-interest exposure target value before the time of the region-of-interest lost.
16. The imaging control method according to claim 15 , wherein in the predetermined period, the exposure control is performed with the exposure correction value obtained so as to make a specific numerical relationship between the set region exposure target value and the set region exposure target value corrected with the exposure correction value equivalent to the specific numerical relationship between the set region exposure target value before the time of the region-of-interest lost and the region-of-interest exposure target value before the time of the region-of-interest lost.
17. A non-transitory computer readable medium storing a program for performing exposure control, the program being executable by a processor to perform operations comprising:
performing exposure control in which a region-of-interest exposure target value calculated on a basis of a region-of-interest photometric value obtained from a first photometric region including at least a region of interest in an input frame is set as an exposure control value, in a case where the region of interest is detected from a captured image;
performing exposure control in which a set region exposure target value calculated on a basis of a set region photometric value obtained from a second photometric region determined in advance in the input frame is set as the exposure control value, in a case where the region of interest is not detected from the captured image; and
obtaining an exposure correction value on a basis of the region-of-interest exposure target value before a time of region-of-interest lost, and then performing exposure control with the exposure control value obtained by correcting the set region exposure target value with the exposure correction value, in a predetermined period in which the region of interest is not detected continuously from the time of the region-of-interest lost in which the region of interest is not detected from the captured image.
18. The non-transitory computer readable medium according to claim 17 , wherein the exposure correction value is a value indicating a relationship between the set region exposure target value before the time of the region-of-interest lost and the region-of-interest exposure target value before the time of the region-of-interest lost.
19. The non-transitory computer readable medium according to claim 18 , wherein in the predetermined period, the exposure control is performed with the exposure correction value obtained so as to make a specific numerical relationship between the set region exposure target value and the set region exposure target value corrected with the exposure correction value equivalent to the specific numerical relationship between the set region exposure target value before the time of the region-of-interest lost and the region-of-interest exposure target value before the time of the region-of-interest lost.