Information processing apparatus, image pickup apparatus, method, and storage medium

Abstract

An information processing apparatus includes an acquisition unit configured to acquire an image captured, a first detection unit configured to detect a subject from the image acquired by the acquisition unit, a second detection unit configured to detect a portion of the subject from the image acquired by the acquisition unit, and a determination unit configured to determine exposure based on a luminance of the subject detected by the first detection unit to reduce a difference between the luminance of the subject and a first luminance that is a target luminance of the subject, and subsequently determine exposure based on a luminance of the portion of the subject detected by the second detection unit to reduce a difference between the luminance of the portion of the subject and a second luminance that is a target luminance of the portion of the subject, the second luminance being different from the first luminance.

Description

TECHNICAL FIELD

[0001] The present application relates to an information processing apparatus, an imaging apparatus, a method, and a storage medium. BACKGROUND

[0002] A conventional technique is known in which, in a case where a human body region is detected from a captured image, the human body region is appropriately exposed, and in a case where a face region is detected, the face region is appropriately exposed (see Patent Literature 1).

[0003] LIST OF CITATIONS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Laid-Open No. 2015-130615 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] A problem to be solved by the present application is to determine exposure appropriate for part detection of a subject.

[0008] MEANS OF SOLVING THE PROBLEM

[0009] To achieve the above object, an information processing apparatus according to an aspect of the present application includes an acquisition unit configured to acquire a captured image, a first detection unit configured to detect a subject from the captured image acquired by the acquisition unit, a second detection unit configured to detect a part of the subject from the captured image acquired by the acquisition unit, and a determination unit configured to determine exposure based on luminance of the subject detected by the first detection unit to reduce a difference between the luminance of the subject and a first luminance that is a target luminance of the subject, and subsequently determine exposure based on luminance of the part of the subject detected by the second detection unit to reduce a difference between the luminance of the part of the subject and a second luminance that is a target luminance of the part of the subject, the second luminance being different from the first luminance.

[0010] ADVANTAGEOUS EFFECTS OF THE INVENTION

[0011] Exposure control appropriate for part detection of a subject can be performed. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 is a diagram showing a configuration of an imaging control system according to a first example embodiment.

[0013] Figure 2 is a diagram showing an internal configuration of a monitoring camera according to the first example embodiment.

[0014] Figure 3is a diagram showing an internal configuration of a client device according to a first example embodiment.

[0015] Figure 4 is a diagram showing a configuration of functions performed by a client device according to a first example embodiment.

[0016] Figure 5 is a diagram showing a captured image in which a face / human body region is underexposed according to a first example embodiment.

[0017] Figure 6 is a diagram showing a captured image in which a face is underexposed according to a first example embodiment.

[0018] Figure 7 is a diagram showing a captured image in which a face is properly exposed and a background is overexposed according to a first example embodiment.

[0019] Figure 8 is a diagram showing a captured image in which a face / human body region is overexposed according to a first example embodiment.

[0020] Figure 9 is a diagram showing a captured image in which a face / human body region is properly exposed according to a first example embodiment.

[0021] Figure 10 is a flowchart showing an exposure control process according to a first example embodiment. DETAILED DESCRIPTION

[0022] Example embodiments of the present application will be described in detail below with reference to the accompanying drawings. The following example embodiments do not limit the present application, and not all combinations of features described in the present example embodiments are essential to the technical solution of the present application. The configuration of the example embodiments can be appropriately modified or changed depending on the specifications of the devices to which the present application is applied and various conditions such as usage conditions and usage environments. The technical scope of the present application is determined by the scope of the claims, and is not limited by the following example embodiments. In addition, the configuration can be provided by appropriately combining the following partial example embodiments.

[0023] One or more of the functional blocks shown in the drawings described below can be implemented by hardware such as an application specific integrated circuit (ASIC) or a programmable logic array (PLA), or can be implemented by a programmable processor that runs software such as a central processing unit (CPU) or a micro processing unit (MPU). One or more of the functional blocks can also be implemented by a combination of software and hardware. Therefore, different functional blocks described below as operation subjects can be implemented as subjects by the same hardware. The ASIC stands for "application specific integrated circuit". The CPU stands for "central processing unit". The MPU stands for "micro processing unit".

[0024] <First Exemplary Example>

[0025] Reference Figures 1 to 10 A first exemplary embodiment is described.

[0026] (Basic Configuration)

[0027] Figure 1 This is a diagram illustrating the configuration of a camera control system 100 according to a first exemplary embodiment of the present invention.

[0028] The camera control system 100 includes a surveillance camera 101, a network 102, a client device 103, an input device 104, and a display device 105. The surveillance camera 101 is a camera device for acquiring moving images and is capable of capturing images of a subject and performing image processing. The surveillance camera 101 and the client device 103 are connected to each other via the network 102. The client device 103 is connected to the input device 104 and the display device 105 and is capable of communicating with them. The client device 103 is a device for processing various types of information and can therefore also be referred to as an information processing device. Furthermore, the client device 103 is a device for controlling the capture of images by the surveillance camera 101 and can therefore also be referred to as a camera control device.

[0029] The input device 104 consists of a mouse, keyboard, etc., and is operated by the user of the client device 103.

[0030] Display device 105 is a device such as a monitor that displays images received from client device 103. Display device 105 can also be used as a user interface (UI) such as a touch panel. In this case, display device 105 can also be used as an input device for inputting instructions, information, data, etc., into client device 103. UI stands for "user interface".

[0031] exist Figure 1 In this embodiment, client device 103, input device 104, and display device 105 are each shown as independent devices, but this exemplary embodiment is not limited to such a configuration. For example, client device 103 and display device 105 may be integrated into one device, or input device 104 and display device 105 may be integrated into one device. Furthermore, client device 103, input device 104, and display device 105 may be integrated into one device. When client device 103 and display device 105 are integrated into one device, this device may take the form of, for example, a personal computer, a tablet terminal, or a smartphone.

[0032] (Structure of a surveillance camera)

[0033] Figure 2is a block diagram showing an internal configuration of the monitoring camera 101. The monitoring camera 101 includes an imaging optical system 201, an image sensor 202, a camera CPU 203, a read only memory (ROM) 204, a random access memory (RAM) 205, an imaging system control unit 206, a communication control unit 207, an analog / digital (A / D) conversion unit 208, an image processing unit 209, an encoder unit 210, and a network interface (I / F) 211. The components 203 to 211 of the monitoring camera 101 are connected to each other through a system bus 212. The ROM stands for "read only memory". The RAM stands for "random access memory". The A / D stands for "analog / digital". The I / F stands for "interface".

[0034] The imaging optical system 201 includes a zoom lens, a focus lens, a blur correction lens, an aperture, and a shutter, and is an optical member unit that collects optical information about a subject. The imaging optical system 201 is connected to the image sensor 202.

[0035] The image sensor 202 is a charge storage type solid-state image sensor such as a complementary metal oxide semiconductor (CMOS) image sensor or a charge coupled device (CCD) image sensor that converts a light flux collected by the imaging optical system 201 into a current value (a signal value). The image sensor 202 is an imaging unit configured to acquire color information by being combined with a color filter or the like. The CMOS stands for "complementary metal oxide semiconductor". The CCD stands for "charge coupled device". The image sensor 202 is connected to the A / D conversion unit 208.

[0036] The camera CPU 203 is a control unit that comprehensively controls the operation of the monitoring camera 101. The camera CPU 203 reads a command stored in the ROM 204 or the RAM 205 to perform processing based on a read result.

[0037] The imaging system control unit 206 controls components of the monitoring camera 101 based on an instruction from the camera CPU 203. For example, the imaging system control unit 206 performs control of the imaging optical system 201 such as focus control, shutter control, and aperture adjustment.

[0038] The communication control unit 207 performs control to transmit a control command (a control signal) issued from the client device 103 to a component of the monitoring camera 101 to the camera CPU 203 through communication with the client device 103.

[0039] The A / D conversion unit 208 converts a light amount of a subject detected by the image sensor 202 into a digital signal (image data). The A / D conversion unit 208 transmits the digital signal to the image processing unit 209.

[0040] The image processing unit 209 performs image processing on image data of a digital signal received from the image sensor 202. The image processing unit 209 is connected to the encoder unit 210.

[0041] The encoder unit 210 performs processing for converting image data processed by the image processing unit 209 into a file format such as Motion JPEG, H.264, or H.265. The encoder unit 210 is connected to the network I / F 211.

[0042] The network I / F 211 is an interface for communicating with an external device such as the client device 103 through the network 102, and is controlled by the communication control unit 207.

[0043] The network 102 is an Internet Protocol (IP) network that connects the monitoring camera 101 and the client device 103. The network 102 includes a plurality of routers, switches, and cables that conform to a communication standard such as Ethernet In the present exemplary embodiment, the communication standard, scale, and configuration of the network 102 are not limited as long as the network 102 enables communication between the monitoring camera 101 and the client device 103. For example, the network 102 can be the Internet, a wired Local Area Network (LAN), a wireless Local Area Network (WLAN), or a Wide Area Network (WAN).

[0044] (Configuration of Client Device)

[0045] Figure 3 is a block diagram that shows an internal configuration of the client device 103.

[0046] The client device 103 includes a client CPU 301, a main storage 302, an auxiliary storage 303, an input I / F 304, an output I / F 305, and a network I / F 306. The components of the client device 103 are communicably connected through a system bus 307.

[0047] The client CPU 301 comprehensively controls the operation of the client device 103. The client CPU 301 can comprehensively control the monitoring camera 101 through the network 102.

[0048] The main storage 302 is a storage device that serves as a temporary data storage area (such as a RAM) of the client CPU 301. For example, the main storage 302 pre-stores patterns (patterns corresponding to a face feature portion and a human body feature portion) for pattern matching to be used when the client device 103 performs face detection or human body detection.

[0049] The auxiliary storage device 303 is a storage device such as a hard disk drive (HDD), a ROM, or a solid state drive (SSD), and stores various programs and various setting data. The HDD stands for "hard disk drive". The SDD stands for "solid state drive".

[0050] The input I / F 304 is used when the client device 103 receives an input (a signal) from the input device 104 or the like.

[0051] The output I / F 305 is used when the client device 103 outputs information (a signal) to the display device 105 or the like.

[0052] The network I / F 306 is used for communication with an external device such as the monitoring camera 101 through the network 102.

[0053] Figure 4 The functions and processes of the client device 103 illustrated in FIG. 1 are implemented by the client CPU 301 processing based on the programs stored in the auxiliary storage device 303. Details thereof will be described below.

[0054] (Function of client device)

[0055] Figure 4 Functions performed by the client device 103 are illustrated. In other words, Figure 4 The components (functional blocks) illustrated in FIG. 1 can be performed by the client CPU 301, and these components are synonymous with the client CPU 301.

[0056] As Figure 4 illustrated, the client CPU 301 of the client device 103 includes an input signal acquisition unit 401, a communication control unit 402, an input image acquisition unit 403, a camera information acquisition unit 404, and a detection method setting unit 405. The client CPU 301 also includes a subject detection unit 406, an exposure determination unit 409, and a display control unit 410. The client device 103 can perform the functions of the units 401 to 409 illustrated in FIG. 1 by using hardware (or software) other than the client CPU 301. Figure 4

[0057] The input signal acquisition unit 401 receives an input from a user through the input device 104.

[0058] The communication control unit 402 performs control to receive an image (an image captured by the monitoring camera 101) transmitted from the monitoring camera 101 through the network 102. Further, the communication control unit 402 performs control to transmit a control command issued from the client device 103 to the monitoring camera 101 through the network 102.

[0059] ​The input image acquisition unit 403 acquires an image received from the monitoring camera 101 by the communication control unit 402 as an object image (an image to which a subject detection process is to be applied) for the subject detection process. Details of the detection process will be described below.

[0060] The camera information acquisition unit 404 acquires, by the communication control unit 402, camera information (imaging information) to be used when the monitoring camera 101 photographs an image of a subject. The camera information (imaging information) corresponds to various information to be used when a subject is photographed and an image thereof is acquired. The camera information includes exposure parameters such as an aperture value, a shutter speed, and a gain. The camera information also includes an exposure correction value for changing an exposure target value to be used in automatic exposure (AE).

[0061] The detection method setting unit 405 sets a predetermined detection method (an appropriate detection method) for an image acquired by the input image acquisition unit 403 among various detection methods including face region detection (face detection) and human body region detection (human body detection). In a case where face detection is performed, the subject detection unit 406 to be described below preferentially detects a face region in an image. In a case where human body detection is performed, the subject detection unit 406 preferentially detects a human body region in an image. Coordinates (including vertex coordinates, width, and height) of the detected face region or human body region are calculated.

[0062] In the present exemplary embodiment, the detection method setting unit 405 sets (selects) a face detection method or a human body detection method. The present embodiment is not limited to this setting. For example, the detection method setting unit 405 can set (be able to select) a detection method that detects a partial feature region (for example, an upper body, a head, or a partial face region such as an eye, a nose, or a mouth) of a person. Further, in the present embodiment, although a subject to be detected is a person, a specific region related to a predetermined subject other than a person can be detected. For example, a predetermined subject preset in the client device 103, such as a face of an animal or a car, can be detected.

[0063] The exposure region setting unit 407 sets an exposure region to be used in AE on the basis of a face region or a human body region calculated by the detection method setting unit 405.

[0064] The exposure target value setting unit 408 sets an appropriate exposure target value on the basis of a detection method set by the detection method setting unit 405. For example, in a case where a face is detected by a detection method, an exposure target value appropriate for a face is set, and in a case where a human body is detected by a detection method, an exposure target value appropriate for a human body is set. Figure 5A scene in which a backlight is shown. The exposure is optimized for the background, so that the human region and the face region are underexposed. In this case, the human is detected from the silhouette, and exposure is performed based on the detected human, and when the face region can be detected due to the increased exposure, exposure is performed based on the detected face region. In the case shown in Figure 6 , the clothes are bright, so even if the exposure is adjusted for the human region, the exposure of the face region is not sufficiently increased, and thus the face region cannot be detected. Therefore, in the scene shown in Figure 5 , in which correction is performed to increase the exposure, a high exposure target value for the human region can be set. As shown in Figure 7 , the human part is slightly overexposed, but the face region can be detected, and the exposure can be appropriately adjusted for the face region. In the case where control is performed so that exposure is adjusted for a certain subject, and then exposure is adjusted for a different subject, the exposure target value for the appropriate region of the certain subject that can pass through the different subject is applied as much as possible, and such a value is useful. For example, a case will be described in which, as shown in Figures 5 to 7 , appropriate adjustment is performed from the human region to the face region. The exposure is adjusted for the human that can be easily detected from the silhouette, and when the exposure of the human region is controlled, the exposure target value for the human region that is appropriate exposure for the face region is set so that the face region can be more likely to be detected.

[0065] Figure 8 A scene in which a person is standing in a room with a night view as the background is shown. In the scene shown in Figure 8 , the exposure is optimized for the night view part of the background, and the person is overexposed. In this case, control is performed to reduce the exposure of both the human region and the face region. In the scene in which correction is performed to reduce the exposure, a low exposure target value for the human region can be set with respect to the target value for the face region. As shown in Figure 9 , the background is underexposed, but the face region can be detected, and the exposure can be appropriately adjusted for the face region.

[0066] The present exemplary embodiment is described using the human region and the face region, but the present exemplary embodiment is not limited to this setting. For example, a detection method that detects a partial feature region of a person (for example, the upper body, the head, or a partial face region such as the eyes, the nose, or the mouth) can be set (can be selected). Furthermore, in the present embodiment, although the subject to be detected is a person, a specific region related to a predetermined subject other than a person can be detected. For example, a predetermined subject that is preset in the client device 103, such as the face of an animal, a car, or a license plate number, can be detected.

[0067] The exposure determination unit 409 determines an exposure level based on the image information on the subject region obtained from the subject detection unit 406, the communication control unit 402 transmits the determined exposure level to the monitoring camera 101, and the monitoring camera 101 then performs exposure control by the control unit 207. As a method of adjusting the exposure level, at least one of an aperture value, a shutter speed, a gain, and a parameter that affects exposure based on an exposure correction value can be used.

[0068] The detailed processing flow related to the camera information acquisition unit 404, the detection method setting unit 405, the subject detection unit 406, and the exposure determination unit 409 will be described below with reference to the flowchart in Figure 10

[0069] The display control unit 410 outputs a captured image that reflects the exposure correction determined by the exposure determination unit 409 to the display device 105 in response to an instruction from the CPU 301.

[0070] (Subect detection processing and exposure determination processing)

[0071] The exposure control processing according to the present embodiment will be described with reference to the flowchart in Figure 10 Figure 1 In the imaging control system 100 illustrated in Figure 10 The processing in the flowchart in

[0072] First, in step S1001, the detection method setting unit 405 sets face detection in the subject detection unit 406, and the subject detection unit 406 performs face detection processing on the input image. The main storage device 302 of the client device 103 stores a pattern corresponding to a facial feature portion and a pattern corresponding to a human body feature portion in advance, and the subject detection unit 406 detects a face region by pattern matching based on these patterns.

[0073] ​​Next, in step S1002, the subject detection unit 406 determines whether a face region has been detected in the image in the face detection processing performed in step S1001. In a case where no face region is detected, the processing proceeds to step S1003, and in a case where at least one face region is detected, the processing proceeds to step S1005.

[0074] In step S1003, the detection method setting unit 405 sets human body detection in the subject detection unit 406, and the subject detection unit 406 performs human body detection processing on the input image. Generally, in a case where a face region is detected, the face can be detected with high accuracy, and the face region of the subject and a region other than the face region can be clearly distinguished. However, if the direction, size, brightness, or the like of the face does not satisfy a condition suitable for face detection, the face region cannot be accurately detected. In contrast, in a case where a human body is detected, a region in which a person is present can be detected regardless of the direction, size, brightness, or the like of the face. In human body detection according to the present embodiment, the entire body does not necessarily have to be detected, and an upper body, a body part above the chest, or a head region including the face can be detected. Figure 7 An example of detection of a face region and a human body region is shown.

[0075] In a case where a pattern matching method is employed as the subject detection method, a pattern (classifier) generated using statistical learning can be used as a pattern for pattern matching. Alternatively, a method other than the pattern matching method can be used to detect a subject. For example, a subject can be detected by using a luminance gradient of a local region. In other words, the subject detection method is not limited to a specific detection method, and various methods such as a detection method based on machine learning and a detection method based on distance information can be employed.

[0076] In step S1004, the subject detection unit 406 determines whether a human body region has been detected in the image in the human body detection processing performed in step S1003. In a case where no human body is detected, the processing ends, and in a case where a human body is detected, the processing proceeds to step S1006.

[0077] In step S1005, the exposure region setting unit 407 sets a focus region to be used in a subsequent step S1008 in the face region detected in step S1001.

[0078] In step S1006, the exposure region setting unit 407 sets a focus region to be used in a subsequent step S1008 in the human body region detected in step S1003.

[0079] In step S1007, an exposure region is set based on the set focus region.

[0080] In step S1008, the exposure determination unit 409 calculates the average luminance value of the exposure region set in step S1007. Specifically, information on the number of the regions of interest (the number of detected faces or human bodies), the positions of the regions of interest, and the sizes of the regions of interest set in step S1005 or step S1006 is applied by the exposure determination unit 409 to the following equation (1).

[0081] [Equation 1]

[0082]

[0083] Here, I(x, y) represents the luminance value of the two-dimensional coordinate position (x, y) in the horizontal direction (x-axis direction) and the vertical direction (y-axis direction) in the image. Further, f represents the number of the regions of interest, (v, h) represents the center coordinates of the regions of interest, k represents the size of the regions of interest in the horizontal direction, and l represents the detection size of the regions of interest in the vertical direction. Thus, the average luminance value of the human body region (the subject) and the average luminance value of the face region (a part of the subject) are calculated.

[0084] In step S1009, the exposure target value setting unit 408 determines the correction amount EV correction for exposure on the basis of the average luminance value calculated in step S1008. First, the exposure determination unit 409 calculates the difference between the average luminance value I object of the region of interest calculated in step S1008 and the target luminance value I object of the region of interest by using equation (2). At this time, the target luminance value I target in the face region is set to the target luminance value I object target_face of the region of interest. object target .

[0085] [Equation 2]

[0086]

[0087] The target luminance value I object targetis determined based on the attention region and the correction direction of exposure. In a case where the correction direction of exposure is a direction in which exposure is increased (in a case of underexposure), a higher target luminance value is set in the human body region than in the face region. In other words, the target luminance value is set to achieve overexposure of the human body region. On the other hand, in a case where the correction direction of exposure is a direction in which exposure is decreased (in a case of overexposure), a lower target luminance value is set in the human body region than in the face region. In other words, the target luminance value is set to achieve underexposure of the human body region. Specifically, the target luminance value for the human body region is determined by the following expression (3).

[0088] [Expression 3]

[0089]

[0090] Here, I object target_body is a target luminance value (first luminance) in a case where the attention region is a human body region. Further, I object target_face is a target luminance value (second luminance) in a case where the attention region is a face region. For example, I object target_face is a target luminance value for achieving appropriate exposure of the face region.

[0091] α is a difference between a target luminance value in a case where exposure is performed based on the face region and a target luminance value in a case where exposure is performed based on the human body region. A predetermined value by which a face can be detected even if an exposure value of the human body region is shifted in the face region due to clothing or the like can be set. In a case where a difference between the first luminance and the second luminance is about 10% of the second luminance, the probability that a face is detected greatly increases. In other words, in a case where the correction direction of exposure is a direction in which exposure is increased, it is desirable to set the target luminance value of the human body region to a value of about 110% of the target luminance value of the face region, and in a case where the correction direction of exposure is a direction in which exposure is decreased, it is desirable to set the target luminance value of the human body region to a value of about 90% of the target luminance value of the face region.

[0092] In addition, if a slightly larger value is set to pass the face region with an appropriate set value, appropriate exposure of the face region can be achieved when exposure correction is performed on the human body.

[0093] Further, in a case where the human body region is detected but the face region is not detected, it is also effective to increase the value of α. This can increase the probability that the face region can be detected in a case where the face cannot be detected using the exposure target value of the human body region.

[0094] In a case where the attention region is a face region, Iobject target_face Set to I object target When the region of interest is a human body image, I object target_body Set to I object target .

[0095] Equation (2) is used again to calculate ΔDiff.

[0096] Next, the exposure determination unit 409 determines the correction amount EV expressed by equation (4). correction EV current The EV value is converted from the subject's brightness value (BV) by the photographic exposure additive system (APEX), and is set based on a program diagram related to exposure control that is pre-stored in the client device 103. current .

[0097] [Formula 4]

[0098]

[0099] Here, parameter β is the factor that affects the exposure value EV when the current exposure value is used. current This parameter β is a coefficient that determines the degree (speed) of exposure correction when adjusting for underexposure or overexposure. If β is set to a large value, the processing speed (processing time) to reach the target value is faster (shorter). However, in cases of incorrect detection or unstable subject detection, the overall brightness of the image can change drastically. Conversely, if β is set to a small value, the processing speed (processing time) to reach the target exposure is slower (longer), but the processing is robust to error detection and shooting conditions. When the difference ΔDiff is greater than or equal to the set threshold Th, β is set to the current exposure value EV. current The exposure correction value.

[0100] In step S1010, the camera information acquisition unit 404 acquires information about the current exposure setting value from the camera. In this exemplary embodiment, the exposure correction value is acquired.

[0101] In step S1011, the exposure determination unit 409 communicates with the monitoring camera 101 through the communication control unit 402, and performs exposure control of the monitoring camera 101 by setting the exposure correction value calculated in step S1009 in the monitoring camera 101.

[0102] In step S1012, the subject detection unit 406 performs face detection in a manner similar to that in step S1001.

[0103] In step S1013, the subject detection unit 406 determines whether a face region is detected in the image in the face detection processing in step S1012. In a case where a face region has been detected, the processing proceeds to step S1014, whereas in a case where no face region has been detected, the processing proceeds to step S1015.

[0104] In step S1014, the exposure determination unit 409 communicates with the monitoring camera 101 through the communication control unit 402, and performs a setting in the monitoring camera 101 to maintain the exposure correction value set in step S1011, and the processing ends.

[0105] In step S1015, the exposure determination unit 409 communicates with the monitoring camera 101 through the communication control unit 402, and performs exposure control of the monitoring camera 101 by setting the exposure correction value acquired in step S1010 in the monitoring camera 101, and the processing ends.

[0106] As described above, in the imaging control system 100 of the present exemplary embodiment, an appropriate exposure region is set based on a face region or a human body region, and exposure control is performed based on the exposure region, so that an exposure value appropriate for a face region or a human body region can be set. For example, even in a strong backlight state such as a store entrance using a glass door, or a stadium gate, an exposure control value appropriate for face detection can be maintained. Therefore, a face of a customer or a spectator subject (person) can be quickly imaged. While some desirable exemplary embodiments of the present application have been described, the present application is not limited to these exemplary embodiments, and can be modified and changed in various ways within the spirit and scope of the present application.

[0107] <Other Exemplary Embodiments>

[0108] The present application can also be realized by a program for realizing one or more functions of the above-described exemplary embodiments being provided to a system or an apparatus via a network or a storage medium, and one or more processors in a computer of the system or the apparatus reading and executing the program. The present application can also be realized by a circuit (e.g., an ASIC) realizing one or more functions.

[0109] The present application is not limited to the above-described embodiments, and various changes and modifications can be made within the spirit and scope of the present application. Therefore, the appended claims are made to inform the public of the scope of the present application.

[0110] This application claims priority to Japanese Patent Application No. 2020-186565, filed November 9, 2020, the entire contents of which are incorporated herein by reference.

Claims

1. An information processing device, comprising: An acquisition unit configured to acquire captured images; A first detection unit is configured to detect a subject from an image acquired by the acquisition unit; A second detection unit is configured to detect a portion of the subject from the image acquired by the acquisition unit; as well as A determining unit is configured to determine exposure based on the brightness of the subject detected by the first detection unit to reduce the difference between the brightness of the subject and a first brightness as a target brightness of the subject, and subsequently determine exposure based on the brightness of the portion of the subject detected by the second detection unit to reduce the difference between the brightness of the portion of the subject and a second brightness as a target brightness of the portion of the subject, wherein the second brightness is different from the first brightness.

2. The information processing device according to claim 1, wherein, When the brightness of the subject is lower than the second brightness, the determining unit sets the first brightness to a brightness higher than the second brightness; when the brightness of the subject is higher than the second brightness, the determining unit sets the first brightness to a brightness lower than the second brightness.

3. The information processing device according to claim 1, wherein, The second brightness is the brightness of the properly exposed portion of the subject, and the first brightness is the brightness of the subject that is either overexposed or underexposed.

4. The information processing device according to claim 1, wherein, In the determining unit, the difference between the first brightness and the second brightness is 10% of the first brightness.

5. The information processing device according to claim 1, wherein, The brightness of the subject is the average brightness value of the subject, and the brightness of the portion of the subject is the average brightness value of the portion of the subject.

6. The information processing device according to claim 1, wherein, When the second detection unit detects a portion of the subject from an image captured based on an exposure determined for the subject, the determining unit determines the exposure for that portion of the subject.

7. The information processing device according to claim 1, wherein, If the second detection unit does not detect the portion of the subject in an image taken based on an exposure determined for the subject, the determining unit increases the difference between the first brightness and the second brightness.

8. The information processing device according to claim 1, wherein, The subject detected by the first detection unit is a human body region, and the portion of the subject detected by the second detection unit is a facial region.

9. A camera device, comprising the information processing device according to any one of claims 1 to 8.

10. A method for determining the exposure of an image, the method comprising: Acquire the captured images; Perform a first detection to detect the subject from the acquired image; A first exposure is determined based on the detected brightness of the subject in order to reduce the difference between the brightness of the subject and a first brightness that is a target brightness of the subject; A second detection is performed to detect a portion of the subject from an image acquired at a determined exposure. as well as A second exposure is determined based on the detected brightness of the portion of the subject to reduce the difference between the brightness of the portion of the subject and a second brightness that is a target brightness of the portion of the subject, wherein the second brightness is different from the first brightness.

11. The method according to claim 10, wherein, In determining the first exposure, if the brightness of the subject is lower than the second brightness, the first brightness is set to a brightness higher than the second brightness; and if the brightness of the subject is higher than the second brightness, the first brightness is set to a brightness lower than the second brightness.

12. The method according to claim 10, wherein, The second brightness is the brightness of the properly exposed portion of the subject, and the first brightness is the brightness of the subject that is either overexposed or underexposed.

13. The method according to claim 10, wherein, In determining the first exposure and the second exposure, the difference between the first brightness and the second brightness is 10% of the first brightness.

14. The method of claim 10, wherein, The brightness of the subject is the average brightness value of the subject, and the brightness of the portion of the subject is the average brightness value of the portion of the subject.

15. The method according to claim 10, wherein, In determining the second exposure, when the portion of the subject is detected in the second detection from an image taken based on the exposure determined for the subject, the exposure of the portion of the subject is determined.

16. The method of claim 10, wherein, In determining the first exposure and the second exposure, if in the second detection the portion of the subject is not detected from the image taken based on the exposure determined for the subject, the difference between the first brightness and the second brightness is increased.

17. The method according to claim 10, wherein, The subject detected in the first detection is a human body region, and the portion of the subject detected in the second detection is a facial region.

18. A computer-readable storage medium storing a program for causing a computer to perform the method according to any one of claims 10 to 17.

19. A computer program product comprising a program that, when executed by a computer, causes the computer to perform the method according to any one of claims 10 to 17.

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