Methods, apparatuses, head-mounted devices, and storage media for exposure control

Abstract

Embodiments of the present disclosure relate to methods, apparatuses, head-mounted devices and storage media for exposure control. The method presented herein includes: obtaining at least one image captured by at least one camera; for each image of the at least one image, determining a first light compensation adjustment amount for a camera corresponding to the image based at least on a first luminance distribution of the image; and updating a light compensation parameter of a light compensation light source associated with the at least one camera based on the first light compensation adjustment amount of each camera of the at least one camera.

Description

Technical Field

[0001] The exemplary embodiments disclosed herein generally relate to the field of optical imaging, and more specifically, to a method, apparatus, head-mounted device, and storage medium for exposure control. Background Technology

[0002] In recent years, extended reality (XR) technologies, including virtual reality (VR), augmented reality (AR), and mixed reality (MR), have made significant progress and have been widely applied in various fields. In some application scenarios of these technologies, the cameras equipped with XR devices can be used to capture images, enabling functions such as spatial positioning and human-computer interaction based on these images. Summary of the Invention

[0003] In a first aspect of this disclosure, a method for exposure control is provided. The method includes: acquiring at least one image captured by at least one camera; for each of the at least one images, determining a first fill light adjustment amount for a camera corresponding to the image, based at least on a first brightness distribution of the image; and updating fill light parameters of a fill light source associated with the at least one camera based on the first fill light adjustment amount of each of the at least one cameras.

[0004] In a second aspect of this disclosure, an apparatus for exposure control is provided. The apparatus includes: an acquisition module configured to acquire at least one image captured by at least one camera; an adjustment amount determination module configured to, for each of the at least one images, determine a first fill light adjustment amount for a camera corresponding to the image, based at least on a first brightness distribution of the image; and an update module configured to update fill light parameters of a fill light source associated with each of the at least one camera based on the first fill light adjustment amount of each of the at least one camera.

[0005] In a third aspect of this disclosure, a wearable device is provided. The device includes at least one camera; a supplementary lighting source; at least one processor; and at least one memory coupled to the at least one processor and storing instructions for execution by the at least one processor. When executed by the at least one processor, the instructions cause the device to perform the method of the first aspect to update the supplementary lighting parameters of the supplementary lighting source.

[0006] In a fourth aspect of this disclosure, a computer-readable storage medium is provided. The computer-readable storage medium stores computer-executable instructions that can be executed by a processor to implement the method of the first aspect.

[0007] In a fifth aspect of this disclosure, a computer program product is provided. The computer program product includes computer-executable instructions that, when executed by a processor, implement the method according to a first aspect of this disclosure.

[0008] It should be understood that the content described in this content section is not intended to limit the key or essential features of the embodiments of this disclosure, nor is it intended to restrict the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0009] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. In the drawings, the same or similar reference numerals denote the same or similar elements, wherein:

[0010] Figure 1 A schematic diagram of an example environment in which embodiments of the present disclosure can be implemented is shown;

[0011] Figure 2 A flowchart illustrating an example process for exposure control according to some embodiments of the present disclosure is shown;

[0012] Figure 3 A flowchart illustrating the overall process according to some embodiments of this disclosure is shown;

[0013] Figure 4 A schematic structural block diagram of an apparatus for exposure control according to some embodiments of the present disclosure is shown; and

[0014] Figure 5 A block diagram of a controller in which one or more embodiments of the present disclosure may be implemented is shown. Detailed Implementation

[0015] Embodiments of this disclosure will now be described in more detail with reference to the accompanying drawings. While some embodiments of this disclosure are shown in the drawings, it should be understood that this disclosure can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this disclosure. It should be understood that the accompanying drawings and embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of protection of this disclosure.

[0016] It should be noted that the headings of any section / subsection provided herein are not limiting. Various embodiments are described throughout this document, and embodiments of any type may be included under any section / subsection. Furthermore, embodiments described in any section / subsection may be combined in any way with any other embodiments described in the same section / subsection and / or different sections / subsections.

[0017] In the description of embodiments of this disclosure, the term "comprising" and similar terms should be understood as open-ended inclusion, i.e., "including but not limited to". The term "based on" should be understood as "at least partially based on". The term "one embodiment" or "the embodiment" should be understood as "at least one embodiment". The term "some embodiments" should be understood as "at least some embodiments". Other explicit and implicit definitions may also be included below. The terms "first", "second", etc., may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0018] The embodiments of this disclosure may involve user data, data acquisition, and / or use. All of these aspects comply with applicable laws, regulations, and relevant provisions. In the embodiments of this disclosure, all data collection, acquisition, processing, manipulation, forwarding, and use are conducted with the user's knowledge and confirmation. Accordingly, in implementing the embodiments of this disclosure, the type, scope of use, and usage scenarios of any data or information that may be involved should be communicated to the user and their authorization obtained in accordance with relevant laws and regulations through appropriate means. The specific methods of notification and / or authorization may vary depending on the actual situation and application scenario, and the scope of this disclosure is not limited in this respect.

[0019] In this specification and the embodiments, any processing of personal information will be carried out only under the premise of legality (such as obtaining the consent of the personal information subject, or being necessary for the performance of a contract), and will only be carried out within the scope stipulated or agreed upon. A user's refusal to process personal information other than that necessary for basic functions will not affect the user's use of basic functions.

[0020] As mentioned earlier, XR devices can currently utilize their built-in cameras to capture images, enabling functions such as spatial positioning and human-computer interaction. Taking VR devices as an example, a VR device can include at least one camera. When a user wears a VR device, the camera can be used to capture the user's surrounding environment, thereby achieving more accurate motion tracking and spatial positioning. When a VR device includes multiple cameras, these cameras can work together to achieve depth perception or stereoscopic vision. Such multiple cameras can also be called a multi-camera system. Conversely, when a VR device includes a single camera, the single camera can be called a monocular camera.

[0021] However, current exposure control schemes for VR device cameras are relatively simple, especially lacking effective exposure control for multi-view cameras. For example, due to limitations in the frame rate and exposure center alignment of multi-view cameras, the exposure time for multi-view cameras often cannot meet the imaging brightness requirements in low-light scenes, thus affecting the positioning accuracy and interaction quality in low-light scenes.

[0022] One approach involves adding a supplementary light source to the VR device to illuminate low-light scenes. In this approach, the supplementary light source uses fixed lighting parameters, or the parameters are adjusted according to the camera's exposure parameters. However, this approach offers limited control flexibility for the supplementary light source. Firstly, the supplementary light source consumes a significant amount of power; prolonged operation in low-light conditions increases the overall power consumption of the device. Secondly, rigid control of the supplementary light source can easily lead to problems such as overexposure of foreground elements and underexposure of the background. At least based on these factors, the current lack of effective control over the supplementary light source easily results in improper exposure, affecting image quality.

[0023] Embodiments of this disclosure provide a scheme for exposure control. According to this scheme, firstly, at least one image captured by at least one camera is acquired. Then, for each of the at least one images, a first fill light adjustment amount for the corresponding camera is determined, based at least on a first brightness distribution of the image. Subsequently, fill light parameters of a fill light source associated with each of the at least one camera are updated based on the first fill light adjustment amount of each camera.

[0024] According to the solution disclosed herein, the supplementary lighting parameters of the supplementary lighting source can be independently adjusted based on the brightness distribution (e.g., a first brightness distribution) of the image captured by the camera. This allows for more flexible control of the supplementary lighting source, thereby improving exposure issues and enhancing image quality. Furthermore, the solution disclosed herein can be applied to XR devices with a monocular camera (e.g., VR devices) or XR devices with multiple cameras. For XR devices with a monocular camera, the solution disclosed herein can automatically adjust the supplementary lighting source based on the image captured by the monocular camera. For XR devices with multiple cameras, the solution disclosed herein can jointly adjust the supplementary lighting source based on multiple images captured by the multiple cameras, thereby adapting the supplementary lighting effect to the exposure needs of each camera in the multiple cameras.

[0025] Figure 1 A schematic diagram of an example environment 100 in which embodiments of the present disclosure can be implemented is shown. (Refer to...) Figure 1 Example environment 100 generally includes wearable device 110. Wearable device 110 can be an XR device such as VR, AR, or MR. Wearable device 110 can be a head-mounted device that can be worn on the head of a user 120. Head-mounted device can be glasses, helmet, or other suitable device.

[0026] Wearable device 110 includes at least one camera. When user 120 wears wearable device 110, the camera of wearable device 110 can be used to capture the environment around user 120, thereby enabling motion tracking and spatial positioning, etc. When wearable device 110 includes multiple cameras, these cameras can work together to achieve depth perception or stereo vision. Such multiple cameras can also be referred to as multi-view cameras.

[0027] In example environment 100, wearable device 110 is shown as including multiple cameras 111-1, 111-2, 111-3, and 111-4. The multiple cameras 111-1, 111-2, 111-3, and 111-4 are configured to take pictures independently to capture respective images 112-1, 112-2, 112-3, and 112-4. For ease of discussion, the multiple cameras 111-1, 111-2, 111-3, and 111-4 are also referred to individually or collectively as camera 111, and the multiple images 112-1, 112-2, 112-3, and 112-4 are also referred to individually or collectively as image 112.

[0028] In example environment 100, cameras 111 are shown positioned in a forward-facing position on wearable device 110. When user 120 wears wearable device 110, each camera 111 can capture the scene as seen by user 120. For example, when user 120 is looking at their own hand, each camera 111 can capture user 120's gestures, etc.

[0029] It should be noted that, in the embodiments disclosed herein, the camera 111 is not limited to... Figure 1 The arrangement shown can be modified or adjusted as needed for image acquisition, including the position and / or number of cameras 111.

[0030] In example environment 100, wearable device 110 also includes a supplementary light source 113 and a controller 114. The supplementary light source 113 is used to provide supplementary lighting for camera 111. The controller 114 can be associated with the supplementary light source 113 for at least controlling the supplementary light source 113. For example, the controller 114 can at least control the supplementary light source 113 to turn on or off. For example, in low ambient light conditions, the controller 114 can control the supplementary light source 113 to turn on, thereby providing supplementary lighting for camera 111. In high ambient light conditions, the controller 114 can control the supplementary light source 113 to turn off, thereby preventing camera 111 from being overexposed.

[0031] It should be understood that the structure and function of the various elements in environment 100 are described for illustrative purposes only and do not imply any limitation on the scope of this disclosure.

[0032] Figure 2 A flowchart of an example process 200 for exposure control according to some embodiments of the present disclosure is shown. The following is in conjunction with... Figure 1 Process 200 will be described. Process 200 can be implemented at the controller 114 of the wearable device 110.

[0033] Reference Figure 2 In box 210, controller 114 acquires at least one image 112 captured by at least one camera 111.

[0034] Although Figure 1 The illustration shows a wearable device 110 including multiple cameras 111; however, in embodiments of this disclosure, the wearable device 110 may also include a single camera 111. This can be determined according to actual needs, and the embodiments of this disclosure do not impose any limitations on this. For ease of discussion, unless otherwise specified, the following description uses a wearable device 110 including multiple cameras 111 as an example to illustrate embodiments of this disclosure.

[0035] As an example, multiple cameras 111 are configured to take pictures independently to capture their respective images 112. The controller 114 can acquire the images 112 captured by each camera 111 so that, in subsequent processes (e.g., the processes shown in boxes 220 and 230), the supplementary light source 113 can be jointly controlled based on these images 112.

[0036] As an example, the supplementary lighting source 113 can be a supplementary lamp or other forms of light source, depending on the requirements of the application scenario and the technical implementation method. The embodiments disclosed herein do not impose any limitations on this. The supplementary lighting source 113 can be a visible light supplementary lighting source or a non-visible light supplementary lighting source. For example, the supplementary lighting source 113 can be a near-infrared (NIR) supplementary lighting source. Compared to visible light supplementary lighting sources, non-visible light supplementary lighting sources can improve the imaging brightness of the camera 111 without affecting the user's vision, thereby improving the user experience.

[0037] As an example, the controller 114 can periodically adjust the supplementary light source 113. For instance, the frequency at which the controller 114 adjusts the supplementary light source 113 can be determined based on the frequency at which the camera 111 captures the image 112. The frequency at which the camera 111 captures the image 112 can also be referred to as the camera 111's refresh rate (Frames Per Second, FPS). For example, each time the camera 111 captures an image 112, the controller 114 can adjust the supplementary light source 113 once based on that image 112.

[0038] In some embodiments, the controller 114's control of the supplementary light source 113 includes at least the control of the on / off state of the supplementary light source 113. In some embodiments, each time the camera 111 captures an image 112, the controller 114 can control the on / off state of the supplementary light source 113 based on the brightness distribution of the image 112.

[0039] As an example, the brightness distribution can indicate the distribution of pixels of different brightness in the image 112. Depending on actual needs, the brightness distribution can use other appropriate granularities besides pixels, and the embodiments of this disclosure do not limit this. As an example, the brightness distribution can be represented by a brightness histogram or other suitable forms.

[0040] The following section explains how the controller 114 controls the activation of the supplementary light source 113.

[0041] In some embodiments, for each of at least one image 112, the controller 114 may determine a first reference illuminance for the image 112 based at least on the relative relationship between a first brightness distribution of the image 112 and the exposure parameters of the camera 111 corresponding to the image 112 when capturing the image 112. After obtaining the first reference illuminance for each image 112, the controller 114 may determine a global reference illuminance for at least one image 112 based on the first reference illuminance of each image 112. If the global reference illuminance is less than a first illuminance threshold, the controller 114 may turn on the supplementary light source 113. If the global reference illuminance is greater than or equal to the first illuminance threshold, the controller 114 may keep the supplementary light source 113 off.

[0042] In some embodiments, the first brightness distribution of image 112 can be determined based on the local brightness distribution of the supplementary lighting region in image 112. In this case, the first brightness distribution can be determined based on the brightness histogram of the supplementary lighting region. In some embodiments, the supplementary lighting region can refer to the region of interest in image 112 during the control process of supplementary lighting source 113. Such a supplementary lighting region can also be called a region of interest (ROI). By setting the supplementary lighting region, it can be ensured that the control process of supplementary lighting source 113 is performed on the region of interest of each image 112, thereby ensuring that the region of interest of each image 112 can be correctly illuminated and improving the accuracy of supplementary lighting control.

[0043] In some embodiments, the supplementary lighting area in each image 112 may be pre-defined. Alternatively, in some embodiments, the supplementary lighting area in each image 112 may be dynamically determined. For example, for each image 112, the controller 114 may perform content recognition on the image 112 and dynamically determine the supplementary lighting area in the image 112 based on the recognition result. For example, for each of at least one image 112, if a specified object exists in the image 112, the controller 114 may determine the area in the image 112 containing the specified object as the supplementary lighting area. If the specified object does not exist in the image 112, the controller 114 may determine a predetermined area in the image 112 as the supplementary lighting area.

[0044] As an example, the designated object can be determined based on the target of interest involved in the application scenario of camera 111. For example, assuming camera 111 is used at least for gesture recognition, then the designated object may include a hand. Assuming camera 111 is used at least for facial recognition, then the designated object may include a face. It should be understood that the description of the designated object here is merely illustrative, and depending on the application scenario of camera 111, the designated object may also include any other suitable object. As an example, the predetermined region may be an area in image 112 that can be illuminated by supplementary lighting source 113. The predetermined region may, for example, be the central region of image 112, or the predetermined region may be determined based on the relative position between camera 111 capturing image 112 and supplementary lighting source 113, etc.

[0045] In this way, when a target of interest appears in the image 112, the controller 114 can adjust the fill light area in the image 112 in real time, so that the area of ​​interest of the image 112 is focused on the target of interest, thereby improving the recognition effect of gestures or faces.

[0046] After determining the first brightness distribution of each image 112, for each image 112, the controller 114 can determine the first reference illuminance of the image 112 based at least on the relative relationship between the first brightness distribution of the image 112 and the exposure parameters of the camera 111 corresponding to the image 112 when capturing the image 112.

[0047] In some embodiments, the controller 114 may determine a first reference illuminance for image 112 based on the relative relationship between the overall brightness distribution of image 112 and the exposure parameters of the camera 111 corresponding to image 112 when capturing image 112. The overall brightness distribution includes a first brightness distribution and a second brightness distribution for image 112. The second brightness distribution may be determined based on the brightness distribution of areas in image 112 other than the supplementary lighting area.

[0048] As mentioned earlier, based on the refresh rate of camera 111, camera 111 can periodically capture image 112. Each time image 112 is captured, camera 111 can be configured with corresponding exposure parameters. These exposure parameters can be determined by controller 114 based on factors such as the brightness of the previously captured image 112. In this way, the exposure parameters of each camera 111 can be dynamically adjusted to adapt to changes in ambient light.

[0049] In some embodiments, exposure parameters may include exposure time. Alternatively or additionally, in some embodiments, exposure parameters may include exposure gain. It should be understood that exposure parameters may also include other elements as needed for exposure control.

[0050] In some embodiments, the reference illuminance can be configured to indicate the true ambient light intensity in image 112. Where the first reference illuminance is determined based on the overall brightness distribution of image 112, the corresponding first reference illuminance can indicate the true ambient light intensity corresponding to the entire image 112.

[0051] In some embodiments, it is assumed that the exposure parameters include exposure time and exposure gain. Then, for each image 112, the controller 114 can determine the average brightness of the entire image 112 based on the overall brightness distribution of that image 112. Subsequently, the controller 114 can determine a first reference illuminance based on the ratio of the average brightness of the image 112 to the product of the exposure time and exposure gain of the corresponding camera 111.

[0052] As an example, the ratio of the average brightness of image 112 to the product of the exposure time and exposure gain of the corresponding camera 111 can be expressed by formula (1):

[0053] D / (G*T);(1) where D is the average brightness of image 112, G is the exposure gain of the corresponding camera 111, and T is the exposure time of the corresponding camera 111.

[0054] In this way, the first reference illuminance can indicate the brightness of image 112 after removing exposure control factors. Such brightness can indicate the true ambient light intensity of image 112. It should be noted that the above method for determining the first reference illuminance is only an example, and the first reference illuminance can also be determined by other appropriate methods as needed.

[0055] After determining the first reference illuminance for each image 112, the controller 114 can determine the global reference illuminance for at least one image 112 based on the first reference illuminance of each image 112. If the global reference illuminance is less than a first illuminance threshold, the controller 114 can turn on the supplementary light source 113. If the global reference illuminance is greater than or equal to the first illuminance threshold, the controller 114 can keep the supplementary light source 113 off.

[0056] As an example, the controller 114 can determine the global reference illuminance of at least one image 112 by calculating the average or weighted average of the first reference illuminances of each image 112. In some embodiments, after the supplementary light source 113 is turned on, the controller 114 can set initial supplementary lighting parameters for the supplementary light source 113, thereby enabling the supplementary light source 113 to provide supplementary lighting based on the initial supplementary lighting parameters. In some embodiments, the supplementary lighting parameters may include the duration of supplementary lighting. Alternatively or additionally, in some embodiments, the supplementary lighting parameters may include the brightness of supplementary lighting. It should be understood that, depending on the needs of supplementary lighting control, the supplementary lighting parameters may also include other elements.

[0057] In this way, the controller 114 can determine the activation timing of the supplementary light source 113 not only based on exposure parameters but also in conjunction with brightness distribution (e.g., a first brightness distribution). This reduces the coupling between the supplementary light source 113 and the exposure parameters, improving the flexibility of the supplementary light source 113 control.

[0058] The following section explains how controller 114 controls the shutdown of supplementary light source 113.

[0059] In some embodiments, for each of at least one image 112, the controller 114 can determine a second reference illuminance for image 112 based on the relative relationship between a second brightness distribution of image 112 and the exposure parameters of the camera 111 corresponding to image 112 when capturing image 112. As mentioned above, the second brightness distribution can be determined based on the brightness distribution of areas other than the supplementary lighting area in image 112. Next, the controller 114 can determine a background reference illuminance for at least one image 112 based on the second reference illuminance of each image 112 in at least one image 112. If the background reference illuminance is greater than a second illuminance threshold, the controller 114 can turn off the supplementary lighting source 113. If the background reference illuminance is less than or equal to the second illuminance threshold, the controller 114 can keep the supplementary lighting source 113 on. As an example, the controller 114 can turn off the supplementary lighting source 113 by setting the supplementary lighting duration of the supplementary lighting source 113 to a predetermined value (e.g., 0).

[0060] In some embodiments, regions in image 112 other than the supplementary lighting region may also be referred to as non-supplementary lighting regions or regions of non-interest. In some embodiments, the second brightness distribution may be determined by subtracting the first brightness distribution from the overall brightness distribution of image 112.

[0061] As mentioned earlier, the reference illuminance can be configured to indicate the true ambient light intensity in image 112. When the second brightness distribution is determined based on the brightness distribution of the non-supplementary lighting areas in image 112, the corresponding second reference illuminance can indicate the true ambient light intensity corresponding to the non-supplementary lighting areas.

[0062] In some embodiments, it is assumed that the exposure parameters include exposure time and exposure gain. Then, for each image 112, the controller 114 can determine the average brightness of the non-illuminating region of image 112 based on the second brightness distribution of image 112. Subsequently, the controller 114 can determine a second reference illuminance based on the ratio of the average brightness of the non-illuminating region of image 112 to the product of the exposure time and exposure gain of the corresponding camera 111.

[0063] In this way, the second reference illuminance can indicate the brightness of the non-illuminating area of ​​image 112 after removing exposure control factors. This brightness is also the true ambient light intensity in the non-illuminating area. It should be noted that the above method for determining the second reference illuminance is only an example, and the second reference illuminance can also be determined by other appropriate methods according to actual needs.

[0064] After determining the second reference illuminance for each image 112, the controller 114 can determine the background reference illuminance for at least one image 112 based on the second reference illuminance of each image 112. If the background reference illuminance is less than the second illuminance threshold, the controller 114 can turn on the supplementary light source 113. If the background reference illuminance is greater than or equal to the second illuminance threshold, the controller 114 can keep the supplementary light source 113 off.

[0065] As an example, the second illuminance threshold can be greater than or equal to the first illuminance threshold, which can be determined according to actual needs. The controller 114 can determine the background reference illuminance of at least one image 112 by calculating the average or weighted average of the second reference illuminance of each image 112.

[0066] Unlike turning on the supplementary light source 113, turning off the supplementary light source 113 focuses more on the brightness in the non-supplementary light area. Since the non-supplementary light area is not illuminated by the supplementary light source 113 or the amount of illumination is small, the brightness distribution in the non-supplementary light area can eliminate the influence of the supplementary light source 113, thereby better reflecting the ambient light brightness and ensuring that the supplementary light source 113 can be turned off in time when the ambient light is high enough.

[0067] The above explains how the controller 114 controls the on / off state of the supplementary light source 113. Below, we will explain how the controller 114 further adjusts the supplementary light source 113 when it is on.

[0068] After acquiring an image 112 captured by each camera 111, in box 220, for each acquired image 112, the controller 114 determines a first fill light adjustment amount for the camera 111 corresponding to the image 112 based at least on a first brightness distribution of the image 112.

[0069] In box 230, controller 114 updates the illumination parameters of the illumination source 113 associated with at least one camera 111 based on the first illumination adjustment amount of each camera 111.

[0070] As an example, for each camera 111, the first fill light adjustment amount can indicate the camera 111's adjustment requirements for fill light parameters. As mentioned above, fill light parameters can include fill light duration and fill light brightness, etc. Assuming the fill light parameters include fill light duration, the first fill light adjustment amount can indicate the amount of adjustment to the fill light duration, and so on. As an example, the first fill light adjustment amount can be represented by a scaling factor, an increment, a decrement, or other forms. When the first fill light adjustment amount is a scaling factor, the controller 114 can update the fill light parameters by multiplying the first fill light adjustment amount by the fill light parameters. When the first fill light adjustment amount is an increment or a decrement, the controller 114 can update the fill light parameters by adding the first fill light adjustment amount to the fill light parameters.

[0071] As mentioned above, the wearable device 110 may include a single camera 111 or multiple cameras 111. When the wearable device 110 includes a single camera 111, the controller 114 can directly update the illumination parameters of the illumination source 113 based on the first illumination adjustment amount of that camera 111. When the wearable device 110 includes multiple cameras 111, the first illumination adjustment amounts of different cameras 111 may differ depending on factors such as the position of the cameras 111. In this case, the controller 114 can combine the first illumination adjustment amounts of each camera 111 to update the illumination parameters of the illumination source 113, thereby achieving joint control of the illumination parameters.

[0072] The following section explains how controller 114 determines the first supplementary lighting adjustment amount.

[0073] In some embodiments, the controller 114 determines the exposure state of the corresponding camera 111 based at least on a first brightness distribution of the image 112. The exposure state indicates the exposure state of the camera 111 after being illuminated by the supplementary lighting source 113 when capturing the image 112. Subsequently, the controller 114 determines a first supplementary lighting adjustment amount to be performed on the camera 111 based on the exposure state of the camera 111.

[0074] The exposure state reflects not only the current image quality of camera 111, but also the lighting effect after the supplementary light source 113 is applied. By analyzing the exposure state of camera 111, controller 114 can automatically determine how to adjust the supplementary light source 113 for that camera 111, thereby achieving closed-loop supplementary lighting control. Furthermore, by introducing exposure state evaluation based on brightness distribution, controller 114 can decouple the strong coupling between supplementary lighting control and exposure parameters, enhancing the flexibility of supplementary lighting.

[0075] In some embodiments, the exposure state may include at least one of overexposure, underexposure, and normal exposure. In some embodiments, the controller 114 may determine the exposure state of the corresponding camera 111 based on a first brightness distribution of image 112. Alternatively, in some embodiments, the controller 114 may first determine whether the camera 111 is in a heavily overexposed state based on the first brightness distribution of image 112. If the camera 111 is not in a heavily overexposed state, the controller 114 may further analyze the exposure state of the camera 111 based on the first brightness distribution of image 112 and the exposure parameters of the camera 111 when capturing image 112.

[0076] For example, for each image 112, the controller 114 can determine, based on the first brightness distribution of the image 112, whether the ratio of overexposed pixels to total pixels in the image 112 exceeds a threshold ratio. If the ratio of overexposed pixels to total pixels in the image 112 exceeds the threshold ratio, the exposure state of the corresponding camera 111 is determined to be a first overexposed state (e.g., a heavily overexposed state). If the ratio of overexposed pixels to total pixels in the image 112 does not exceed the threshold ratio, the controller 114 can determine that the exposure state of the corresponding camera 111 is not a first overexposed state. In this case, the controller 114 can further determine whether the image 112 belongs to other exposure states based on the first brightness distribution of the image 112 and the exposure parameters of the corresponding camera 111 when capturing the image 112. For example, the controller 114 can determine the average brightness of the image 112 (e.g., the average brightness in the fill light area) based on the first brightness distribution of the image 112. Subsequently, the controller 114 determines the exposure state of the camera 111 based on the relative relationship between the average brightness of the image 112 and the exposure parameters of the corresponding camera 111 when capturing the image 112.

[0077] As an example, overexposed pixels can refer to pixels in image 112 whose brightness values ​​exceed a brightness threshold. This pixel-level brightness statistics method has good accuracy, thereby effectively improving the controller 114's ability to perceive the quality of image 112. As an example, the threshold ratio can be pre-configured. The threshold ratio can indicate the upper limit of the proportion of overexposed pixels. In this case, the first overexposure state can also be called a severe overexposure state. By analyzing whether the proportion of overexposed pixels in image 112 exceeds the upper limit, the controller 114 can quickly identify whether there is a large area of ​​excessive brightness in image 112, thereby determining whether the camera 111 is in a severe overexposure state. If it is determined that the camera 111 is not in a severe overexposure state, the controller 114 can combine the first brightness distribution and the exposure parameters of the camera 111 to further identify whether the camera 111 is in a slightly overexposed state, an underexposed state, or a normal exposure state, etc., with richer information. In this way, the controller 114 can support multi-level exposure state classification, improving response flexibility.

[0078] As mentioned above, the exposure parameters of camera 111 may include exposure gain and exposure duration. Based on this, controller 114 can determine the exposure state of camera 111 based on the ratio of the average brightness of image 112 to the product of camera 111's exposure gain and exposure duration (e.g., the reference illuminance mentioned above). For example, if the ratio of the average brightness of image 112 to the product of camera 111's exposure gain and exposure duration is higher than a reference ratio range, controller 114 can determine that the exposure state of camera 111 is a second overexposure state (e.g., a slightly overexposed state). If the ratio of the average brightness of image 112 to the product of camera 111's exposure gain and exposure duration is lower than a reference ratio range, controller 114 can determine that the exposure state of camera 111 is an underexposure state. If the ratio of the average brightness of image 112 to the product of camera 111's exposure gain and exposure duration is within a reference ratio range, controller 114 can determine that the exposure state of camera 111 is a normal exposure state. As an example, the average brightness of image 112 described here may refer to the average brightness of the supplementary lighting area of ​​image 112.

[0079] By analyzing the ratio of the average brightness of image 112 to the product of the exposure gain and exposure time of camera 111, and combining this with a reference ratio range to determine the exposure state, controller 114 can achieve accurate perception and dynamic response to the quality of image 112 and ambient light without relying on a single parameter.

[0080] After determining the exposure state of camera 111 (e.g., the first overexposure state, second overexposure state, underexposure state, or normal exposure state mentioned above), controller 114 can determine a first fill light adjustment amount for camera 111 based on the type of exposure state. For example, if the exposure state is underexposure, controller 114 can determine that the first fill light adjustment amount is an extension of the fill light duration of fill light source 113. As an example, the extension amount here can be pre-configured. For example, the extension amount can indicate extending the fill light duration to 1.1 times the current fill light duration or other values. If the exposure state is the first overexposure state, controller 114 can determine that the first fill light adjustment amount is a reduction of the fill light duration of fill light source 113 and the reduction amount is a first reduction amount. As an example, the first reduction amount can be pre-configured. For example, the first reduction amount can indicate extending the fill light duration to 0.85 times the current fill light duration or other values. If the exposure state is a second overexposure state, the controller 114 can determine that the first fill light adjustment amount is to shorten the fill light duration of the fill light source 113, and the shortening amount is a second shortening amount. The first shortening amount is greater than the second shortening amount. As an example, the second shortening amount can be pre-configured. For example, the second shortening amount can indicate extending the fill light duration to 0.9 times the current fill light duration or other values. If the exposure state is a normal exposure state, the controller 114 can determine that the first fill light adjustment amount is to keep the fill light duration of the fill light source 113 unchanged.

[0081] By employing differentiated supplementary lighting duration adjustment strategies for different exposure states, the controller 114 can achieve precise control and energy-saving optimization of the supplementary lighting source 113 while ensuring the quality of the image 112.

[0082] The following section explains how the controller 114 updates the fill light parameters based on the first fill light adjustment amount of each camera 111.

[0083] As mentioned above, the controller 114 can periodically adjust the supplementary lighting source 113. For example, after each image 112 is captured by the camera 111, the controller 114 can determine the first supplementary lighting adjustment amount of the camera 111 and determine whether the supplementary lighting parameters of the supplementary lighting source 113 need to be updated. For example, for a certain time period, this time period can be divided into multiple moments based on the adjustment frequency of the supplementary lighting source 113 by the controller 114. At each of the multiple moments, the controller 114 can determine whether the supplementary lighting parameters need to be updated. In other words, the supplementary lighting parameters are determined to need to be updated at each of the multiple moments.

[0084] In some embodiments, the first fill light adjustment amount is determined at a first moment among multiple moments. Based on this, the controller 114 can determine update conditions for the fill light parameters at the first moment based on whether the fill light parameters are changed at a second moment among multiple moments. The second moment precedes the first moment. Then, the controller 114 can determine whether the update conditions are met, at least based on the difference between the first fill light adjustment amount of each camera 111 and a reference fill light adjustment amount. If the update conditions are met, the controller 114 can update the fill light parameters based on the first fill light adjustment amount of each camera 111. If the update conditions are not met, the controller 114 can determine that no update of the fill light parameters is needed.

[0085] As an example, the first time point can be any of multiple time points. The second time point can be a time point adjacent to and preceding the first time point. At the second time point, the controller 114 can determine whether the supplementary lighting parameters need to be updated. If it is determined that no update is needed, the supplementary lighting parameters will remain unchanged. If it is determined that an update is needed, since the update is jointly controlled by multiple first supplementary lighting adjustment amounts, the supplementary lighting parameters may be changed or remain unchanged after the update.

[0086] As an example, at the second moment, if the lighting parameters remain unchanged, it indicates that the overall lighting effect of the lighting source 113 can meet the needs of each camera 111. Such a lighting source 113 can be considered to be in a "stable" state. At the second moment, if the lighting parameters are changed, it indicates that the lighting effect of the lighting source 113 cannot meet the needs of at least some cameras 111. Such a lighting source 113 can be considered to be in an "unstable" state requiring adjustment.

[0087] Based on whether the supplementary lighting source 113 is "stable" or "unstable" at the second moment, the controller 114 can determine the update conditions to be adopted at the first moment. The update conditions instruct the controller 114 on the strategy to determine whether the supplementary lighting parameters need to be updated at the first moment. For example, if the supplementary lighting source 113 is in a "stable" state at the second moment, the controller 114 can consider the supplementary lighting source 113 to be operating stably overall. In this case, the update conditions can tend to be more stringent, allowing the controller 114 to ignore small brightness fluctuations and improve the operational stability of the supplementary lighting source 113. If the supplementary lighting source 113 is in an "unstable" state at the second moment, the controller 114 can consider the supplementary lighting source 113 to be in the process of optimization and adjustment. In this case, the update conditions can tend to be more lenient, prompting the controller 114 to update the supplementary lighting parameters more frequently, so that the supplementary lighting source 113 can quickly meet the supplementary lighting needs of each camera 111.

[0088] In some embodiments, the controller 114 may first determine whether there is a camera 111 in the first overexposure state mentioned above. If any camera 111 is in the first overexposure state, the controller 114 may determine that an update to the fill light parameters needs to be performed immediately. For example, if the first brightness distribution of one or more images 112 in at least one image 112 indicates that the ratio of overexposed pixels to total pixels in the corresponding image 112 exceeds a threshold ratio, the controller 114 may directly update the fill light parameters based on the first fill light adjustment amount of each camera 111 in at least one camera 111. If none of the cameras 111 are in the first overexposure state, the controller 114 may perform a process for determining update conditions. For example, if the first brightness distribution of each image 112 in at least one image 112 indicates that the ratio of overexposed pixels to total pixels in the corresponding image 112 does not exceed a threshold ratio, the controller 114 may determine the update conditions for the fill light parameters at the first time based on whether the fill light parameters have been changed at the second time.

[0089] In this way, the controller 114 can perform graded responses based on the exposure state of the camera 111. For example, when the camera 111 is in a severely overexposed state, the controller 114 prioritizes response speed to quickly suppress overexposure. When the camera 111 is not in a severely overexposed state, the controller 114 can appropriately relax the requirements for response speed while ensuring adjustment accuracy, thereby achieving more precise and stable supplementary lighting control.

[0090] In some embodiments, if the supplementary lighting parameters are changed at a second time, the controller 114 can determine that the supplementary lighting source 113 is in an "unstable" state. At this time, the controller 114 can determine that the update condition is a relatively lenient first update condition. Based on this, the controller 114 can determine the average value of the first supplementary lighting adjustment amount of each camera 111 in at least one camera 111. Then, the controller 114 can determine whether the first update condition is met by comparing this average value with a reference supplementary lighting adjustment amount. For example, if the difference between the average value of the first supplementary lighting adjustment amount of each camera 111 in at least one camera 111 and the reference supplementary lighting adjustment amount is greater than a first difference threshold, it is determined that the first update condition is met. Otherwise, it is determined that the first update condition is not met.

[0091] As an example, the reference fill light adjustment amount can be pre-configured. For instance, if the first fill light adjustment amount indicates an adjustment factor for the fill light parameter (such as 1.1, 1, or 0.9 as mentioned above), the reference fill light adjustment amount can be "1" or the like.

[0092] In this way, the controller 114 can efficiently determine the update conditions while ensuring accuracy, which is conducive to the rapid adjustment of the supplementary lighting parameters.

[0093] In some embodiments, if the supplementary lighting parameters are not changed at the second time moment, the controller 114 can determine that the supplementary lighting source 113 is in a "stable" state. At this time, the controller 114 can determine that the update condition is a more stringent second update condition. Based on this, the controller 114 can acquire the cumulative difference associated with the second update condition. The cumulative difference indicates the difference between the second supplementary lighting adjustment amount of each camera 111 in at least one camera 111 at the second time moment and the reference supplementary lighting adjustment amount. Once the cumulative difference is obtained, the controller 114 can accumulate the difference between the first supplementary lighting adjustment amount of each camera 111 in at least one camera 111 and the reference supplementary lighting adjustment amount at the first time moment into the cumulative difference. If the accumulated difference is greater than a second difference threshold, the controller 114 can determine that the second update condition is met. Otherwise, the controller 114 can determine that the second update condition is not met.

[0094] As an example, the second fill light adjustment amount of each camera 111 in at least one camera 111 is the fill light adjustment amount determined at a second time. The method for determining the second fill light adjustment amount can refer to the method for determining the first fill light adjustment amount, and therefore will not be repeated here. As an example, the cumulative difference can indicate the difference between the average value of the second fill light adjustment amount of each camera 111 in at least one camera 111 and a reference fill light adjustment amount. In this case, when accumulating the cumulative difference, the controller 114 can accumulate the difference between the average value of the first fill light adjustment amount of each camera 111 in at least one camera 111 and the reference fill light adjustment amount into the cumulative difference.

[0095] It should be noted that although this article uses the first and second moments as examples to illustrate the cumulative difference, it should be understood that at each of the multiple moments, once the controller 114 determines that the supplementary lighting source 113 of the previous moment is in a "stable" state, it can acquire the cumulative difference accumulated at the previous moment. Then, the controller 114 can calculate the average value of the supplementary lighting adjustment amount of each camera 111 at the current moment. Subsequently, the controller 114 can accumulate the difference between this average value and the reference supplementary lighting adjustment amount into the acquired cumulative difference, and determine whether the second update condition for the current moment is met based on the accumulated cumulative difference.

[0096] For example, if the supplementary lighting parameters are not changed at the first moment, the controller 114 can determine that the supplementary lighting source 113 is in a "stable" state. At this time, the controller 114 can determine that the update condition for the supplementary lighting parameters at the third moment is a more stringent second update condition. The third moment can be a moment following the first moment among multiple moments. Based on this, the controller 114 can obtain the cumulative difference at the first moment. Then, the controller 114 can accumulate the difference between the average of the third supplementary lighting adjustment amount of each camera 111 in at least one camera 111 and the reference supplementary lighting adjustment amount to the cumulative difference. If the accumulated difference is greater than the second difference threshold, the controller 114 can determine that the second update condition at the third moment is met. Otherwise, the controller 114 can determine that the second update condition at the third moment is not met. The third supplementary lighting adjustment amount of each camera 111 in at least one camera 111 can be determined at the third moment.

[0097] In this way, the controller 114 can ignore small brightness fluctuations and maintain the stable operation of the supplementary light source 113. Furthermore, when the accumulated difference reaches a certain level, the controller 114 can determine that the brightness fluctuation is not negligible and thus respond promptly to adjust the supplementary lighting parameters. In addition, if a large brightness fluctuation suddenly occurs at a certain moment, by appropriately setting a second difference threshold, the controller 114 can also respond promptly to ensure effective handling of this situation.

[0098] If the update conditions are met or a camera 111 is found to be in a first overexposure state, the controller 114 can update the lighting parameters based on the lighting adjustment amount of each camera 111. As mentioned above, the lighting parameters may include the lighting duration, and the first lighting adjustment amount of each camera 111 in at least one camera 111 may include the lighting duration adjustment amount to be performed for camera 111. In this case, the controller 114 can update the lighting duration based on the average of the lighting duration adjustment amounts of each camera 111 in at least one camera 111 (e.g., superposition or multiplication). In this way, the controller 114 can comprehensively control the lighting source 113 in conjunction with the lighting requirements of each camera 111, so that the controlled lighting source 113 can take into account the exposure requirements of each camera 111 and improve the lighting control accuracy.

[0099] In some embodiments, in addition to updating the fill light parameters, the controller 114 can also update the exposure parameters of the camera 111. Depending on whether the fill light source 113 is turned on, the controller 114 can employ different strategies to update the exposure parameters of the camera 111. Furthermore, unlike the multi-camera 111 joint control method for fill light parameters, the adjustment amount of the exposure parameters of each camera 111 can be independently determined by the image 112 captured by that camera 111, and different cameras 111 can operate independently without interference.

[0100] The following section will first explain how the controller 114 updates the exposure parameters with the supplementary light source 113 in the on state.

[0101] In some embodiments, for each of at least one image 112, the controller 114 can determine the exposure measurement information of the image 112 based on a first brightness distribution and a second brightness distribution of the image 112. As mentioned above, the first brightness distribution can be determined based on the brightness distribution of the illuminated area in the image 112, and the second brightness distribution can be determined based on the brightness distribution of other areas (e.g., non-illuminated areas) in the image 112. After obtaining the exposure measurement information, the controller 114 can update the exposure parameters of the camera 111 corresponding to the image 112 based on the difference between the exposure measurement information and the exposure reference information.

[0102] In some embodiments, exposure measurement information may indicate a brightness measurement value after exposure. Controller 114 may determine the average brightness of the entire image 112 based on the overall brightness distribution of image 112 (e.g., based on a brightness histogram containing all pixels of image 112). Controller 114 may determine a second brightness distribution of image 112 by subtracting a first brightness distribution from the overall brightness distribution. Controller 114 may then determine the average brightness of the non-illuminating areas of image 112 based on the second brightness distribution. Controller 114 may then determine a brightness measurement value based on the average or weighted average of the average brightness of the entire image 112 and the average brightness of the non-illuminating areas.

[0103] In some embodiments, the exposure reference information may indicate a target brightness value after exposure. The controller 114 may determine the difference between the measured brightness value and the target brightness value. The controller 114 may then acquire an exposure parameter adjustment amount associated with that difference. Next, the controller 114 may update the exposure parameters of the camera 111 based on this exposure parameter adjustment amount, by superimposing or multiplying it with the current exposure parameters of the camera 111.

[0104] In this way, the control of exposure parameters incorporates consideration of the fill light effect, thereby making the adjustment of exposure parameters more accurate and improving the exposure control effect.

[0105] The following explanation will cover how the controller 114 updates the exposure parameters with the supplementary light source 113 in the off state.

[0106] When the supplementary lighting is off, the controller 114 no longer needs to distinguish between supplementary lighting areas and non-supplementary lighting areas. Based on this, for each image 112 in at least one image 112, the controller 114 can determine the exposure measurement information of that image 112 based on the overall brightness distribution of that image 112. After obtaining the exposure measurement information, the controller 114 can update the exposure parameters of the camera 111 corresponding to that image 112 based on the difference between the exposure measurement information and the exposure reference information.

[0107] As mentioned earlier, exposure measurement information indicates the brightness measurement value after exposure, and exposure reference information indicates the target brightness value after exposure. Based on this, controller 114 can determine the average brightness of the entire image 112 based on the overall brightness distribution. Then, controller 114 can determine the brightness measurement value based on the average brightness of the entire image 112. Next, controller 114 can determine the difference between the brightness measurement value and the target brightness value. Then, controller 114 can acquire the exposure parameter adjustment amount associated with this difference, and update the exposure parameters of camera 111 based on this exposure parameter adjustment amount by superimposing or multiplying it with the current exposure parameters of camera 111.

[0108] Figure 3 A flowchart of a general process 300 according to some embodiments of the present disclosure is shown. The following is in conjunction with… Figure 3 Further details are provided for process 200.

[0109] In box 301, controller 114 acquires multiple images 112 captured by multiple cameras 111, as well as exposure parameters of each camera 111 when capturing image 112. Exposure parameters may include, for example, exposure gain and exposure duration.

[0110] In box 302, controller 114 obtains the upper and lower limits of the fill light parameters.

[0111] As an example, fill light parameters can include fill light duration and fill light brightness. For ease of discussion, the following discussion uses fill light duration as an example. As an example, the upper limit of fill light duration can be determined based on the refresh rate (or frame rate) of camera 111. For example, the upper limit of fill light duration could be the longest duration at which the fill light source 113 will not overheat at that refresh rate. The lower limit of fill light duration can be determined based on the exposure requirements of each row of pixels. For example, the lower limit of fill light duration could be the minimum exposure duration per row of pixels.

[0112] In frame 303, controller 114 determines whether to turn the supplementary light source 113 on or off.

[0113] As an example, with the supplementary light source 113 turned on, for each image 112, the controller 114 can determine the reference illuminance (e.g., a second reference illuminance) of the non-supplementary light area of ​​the image 112 based on the average brightness of the non-supplementary light area. Then, the controller 114 determines the background reference illuminance of multiple images 112 based on the average or weighted average of the second reference illuminances of each image 112. If the background reference illuminance is greater than a corresponding illuminance threshold (e.g., a second illuminance threshold), the controller 114 can turn off the supplementary light source 113. If the background reference illuminance is less than or equal to the second illuminance threshold, the controller 114 can keep the supplementary light source 113 on.

[0114] As an example, with the supplementary light source 113 off, for each image 112, the controller 114 can determine the reference illuminance (e.g., a first reference illuminance) of the entire image 112 based on the average brightness of the entire image 112. Then, the controller 114 determines the global reference illuminance of multiple images 112 based on the average or weighted average of the first reference illuminances of each image 112. If the global reference illuminance is greater than a corresponding illuminance threshold (e.g., a first illuminance threshold), the controller 114 can turn on the supplementary light source 113. If the global reference illuminance is less than or equal to the first illuminance threshold, the controller 114 can keep the supplementary light source 113 off.

[0115] In box 304, with the supplementary light source 113 on, the controller 114 can determine the brightness distribution of each of the multiple images 112, such as a first brightness distribution, a second brightness distribution, or an overall brightness distribution. As an example, the second brightness distribution can be determined by subtracting the first brightness distribution from the overall brightness distribution.

[0116] In box 305, controller 114 sets the illumination duration of supplementary light source 113 to an initial value.

[0117] In frame 306, controller 114 determines the fill light area for each image 112.

[0118] As an example, for an image 112 containing a specified object, the controller 114 can determine the area in the image 112 containing the specified object as the fill light area. For an image 112 that does not contain a specified object, the controller 114 can determine a predetermined area in the image 112 as the fill light area. The predetermined area may be, for example, an area in the image 112 that can be illuminated by the fill light source 113.

[0119] In box 307, controller 114 determines the amount of illumination adjustment (e.g., the first amount of illumination adjustment) for camera 111 corresponding to each image 112 based at least on the brightness distribution (e.g., the first brightness distribution) of the illumination area of ​​each image 112.

[0120] As an example, for each image 112, the controller 114 can first determine whether the camera 111 corresponding to the image 112 is in a first overexposure state based on a first brightness distribution of the image 112. If the camera 111 corresponding to the image 112 is in a first overexposure state, the controller 114 can determine that the first fill light adjustment amount of the camera 111 is to shorten the fill light duration. For example, the first fill light adjustment amount could be to shorten the fill light duration to 0.85 times the current fill light duration.

[0121] As an example, for each image 112, when the controller 114 determines that the image 112 is not in the first overexposure state, it can further determine whether the corresponding camera 111 is in the second overexposure state, underexposure state, or normal exposure state based on the first brightness distribution of the image 112 and the exposure parameters of the camera 111 corresponding to the image 112 when capturing the image 112.

[0122] For example, for each image 112, the controller 114 can calculate the average brightness (also known as the core metering value AEV_core) of the illuminated area of ​​image 112 based on a first brightness distribution of image 112. If the ratio of the average brightness of the illuminated area of ​​image 112 to the product of the exposure gain and exposure time of the corresponding camera 111 is higher than a reference ratio range, the exposure state of camera 111 is determined to be a second overexposure state. If the ratio of the average brightness of the illuminated area of ​​image 112 to the product of the exposure gain and exposure time of the corresponding camera 111 is lower than a reference ratio range, the exposure state of camera 111 is determined to be an underexposure state. If the ratio of the average brightness of the illuminated area of ​​image 112 to the product of the exposure gain and exposure time of the corresponding camera 111 is within a reference ratio range, the exposure state of camera 111 is determined to be a normal exposure state.

[0123] In box 308, controller 114 can determine whether the fill light source 113 is in a stable state at the current moment, based at least on the exposure state of each camera 111, and decide whether to update the fill light duration accordingly.

[0124] As an example, if any camera 111 is in the first exposure state, the controller 114 can determine that the supplementary light source 113 is in an unstable state at the current moment. If none of the cameras 111 are in the first exposure state, the controller 114 can further determine whether the supplementary light source is in a stable state at the current moment based on the first supplementary light adjustment amount of each camera 111 and whether the supplementary light source 113 was in a stable state at the previous moment.

[0125] For example, if the supplementary lighting source 113 was in a steady state at the previous moment, the controller 114 can acquire a cumulative difference, which at least indicates the difference between the average of the supplementary lighting adjustment amounts (e.g., the second supplementary lighting adjustment amount) of each camera 111 at the previous moment and a reference supplementary lighting adjustment amount. The controller 114 can then accumulate the difference between the average of the first supplementary lighting adjustment amounts of each camera 111 and the reference supplementary lighting adjustment amount into this cumulative difference. If the accumulated difference is greater than a corresponding difference threshold (e.g., a second difference threshold), the controller 114 can determine that the supplementary lighting source 113 is in an unstable state at the current moment. Otherwise, the controller 114 can determine that the supplementary lighting source 113 is in a stable state at the current moment.

[0126] For example, if the supplementary lighting source 113 was in an unstable state at the previous moment, the controller 114 can calculate the difference between the average of the first supplementary lighting adjustments of each camera 111 and the reference supplementary lighting adjustment. If this difference is greater than a corresponding difference threshold (e.g., the first difference threshold), the controller 114 can determine that the supplementary lighting source 113 is in an unstable state at the current moment. Otherwise, the controller 114 can determine that the supplementary lighting source 113 is in a stable state at the current moment.

[0127] In box 309, if the supplementary light source 113 is unstable at the current moment, the controller 114 can update the supplementary light duration based on the first supplementary light adjustment amount of each camera 111. If the supplementary light source 113 is stable at the current moment, the controller 114 can determine that the supplementary light duration does not need to be updated.

[0128] As an example, controller 114 can determine the average or weighted average of the first fill light adjustment amount for each camera 111. Then, controller 114 can multiply this average or weighted average by the current value of the fill light duration to update the fill light duration. As an example, the updated fill light duration needs to be between an upper and lower limit of the fill light duration. As an example, controller 114 can convert the fill light duration into a representation of control commands for the fill light source 113, such as a representation in pixel rows.

[0129] In addition to the duration of the fill light, the controller 114 can also update the exposure parameters of the corresponding camera 111 for each image 112 when the fill light source 113 is turned on.

[0130] For example, in box 310, controller 114 can determine the average brightness of image 112 (the average brightness of the entire image 112, also known as the global metering value AEV_all) based on the overall brightness distribution of image 112.

[0131] In box 311, controller 114 can determine the average brightness (also known as background metering value AEV_back) of the non-supplementary lighting area of ​​image 112 based on the second brightness distribution of image 112.

[0132] In box 312, controller 114 can determine the brightness measurement value after exposure based on the average or weighted average of the average brightness of image 112 and the average brightness of the non-supplementary area of ​​image 112.

[0133] In block 313, controller 114 can determine the corresponding exposure parameter adjustment amount for camera 111 based on the difference between the measured brightness value and the target brightness value.

[0134] In box 314, controller 114 can update the exposure parameters of the corresponding camera 111 based on the adjustment amount of the exposure parameters.

[0135] The controller 114 can also update the exposure parameters of the corresponding camera 111 for each image 112 when the supplementary light source 113 is turned off.

[0136] For example, in box 315, controller 114 can determine the average brightness of image 112 (the average brightness of the entire image 112, also known as the global metering value AEV_all) based on the overall brightness distribution of image 112.

[0137] In box 316, controller 114 can determine the post-exposure brightness measurement based on the average brightness of image 112. Then, controller 114 can perform the steps shown in boxes 313 and 314 to update the exposure parameters of the corresponding camera 111.

[0138] As can be clearly understood from the various embodiments described above, the embodiments of this disclosure can select different supplementary light source switching logics based on whether the supplementary light source 113 is turned on or off. When the supplementary light source 113 is off, the embodiments of this disclosure determine whether to turn on the supplementary light source 113 based on global brightness detection of image 112. When the supplementary light source 113 is on, the embodiments of this disclosure determine whether to turn off the supplementary light source 113 based on brightness detection of non-supplementary light areas. Furthermore, the embodiments of this disclosure jointly control the supplementary light source based at least on the brightness distribution of supplementary light areas in multiple images 112 (and may further combine the exposure parameters of each camera), thereby improving the accuracy of supplementary lighting. Moreover, the embodiments of this disclosure can also update the exposure parameters while considering the supplementary lighting effect. In this way, the embodiments of this disclosure adjust the supplementary lighting parameters and exposure parameters independently but interrelatedly, thereby improving the flexibility and accuracy of controlling the supplementary lighting parameters and exposure parameters, and improving problems of improper exposure (such as overexposure of interactive areas and underexposure of the background).

[0139] Embodiments of this disclosure also provide corresponding apparatus for implementing the above methods or processes. Figure 4 A schematic structural block diagram of an apparatus 400 for exposure control according to some embodiments of the present disclosure is shown. The apparatus 400 may be implemented as or included in a controller 114. The various modules / components in the apparatus 400 may be implemented by hardware, software, firmware, or any combination thereof.

[0140] Reference Figure 4 The apparatus 400 includes an acquisition module 410, an adjustment amount determination module 420, and an update module 430. The acquisition module 410 is configured to acquire at least one image captured by at least one camera. The adjustment amount determination module 420 is configured to, for each of the at least one images, determine a first fill light adjustment amount for the camera corresponding to the image, based at least on a first brightness distribution of the image. The update module 430 is configured to update the fill light parameters of the fill light source associated with each of the at least one camera based on the first fill light adjustment amount of each of the at least one camera.

[0141] In some embodiments, the adjustment amount determination module 420 is further configured to: for each of at least one image, determine the exposure state of the corresponding camera based at least on a first brightness distribution of the image, wherein the exposure state indicates the exposure state of the camera after being illuminated by a supplementary light source when capturing the image; and determine a first supplementary lighting adjustment amount to be performed on the camera based on the camera's exposure state.

[0142] In some embodiments, the adjustment amount determination module 420 is further configured to: determine whether the ratio of overexposed pixels to total pixels in the image exceeds a threshold ratio based on a first brightness distribution of the image; determine the camera's exposure state as a first overexposed state in response to determining that the ratio of overexposed pixels to total pixels in the image exceeds the threshold ratio; determine the average brightness of the image based on the first brightness distribution of the image in response to determining that the ratio of overexposed pixels to total pixels in the image does not exceed the threshold ratio; and determine the camera's exposure state based on the relative relationship between the average brightness of the image and the camera's exposure parameters when capturing the image.

[0143] In some embodiments, the camera's exposure parameters include exposure gain and exposure duration. The adjustment amount determination module 420 is further configured to: determine the camera's exposure state as a second overexposure state in response to the ratio of the average brightness of the image to the product of the camera's exposure gain and exposure duration being higher than a reference ratio range; or determine the camera's exposure state as an underexposure state in response to the ratio of the average brightness of the image to the product of the camera's exposure gain and exposure duration being lower than a reference ratio range; or determine the camera's exposure state as a normal exposure state in response to the ratio of the average brightness of the image to the product of the camera's exposure gain and exposure duration being within a reference ratio range.

[0144] In some embodiments, the camera's exposure state includes at least a first overexposure state, a second overexposure state, an underexposure state, or a normal exposure state, and the fill light parameter includes the fill light duration. The adjustment amount determination module 420 is further configured to: in response to determining that the exposure state is underexposure, determine that the first fill light adjustment amount is an extension of the fill light duration of the fill light source; or in response to determining that the exposure state is first overexposure, determine that the first fill light adjustment amount is a reduction of the fill light duration of the fill light source with a first reduction amount; or in response to determining that the exposure state is second overexposure, determine that the first fill light adjustment amount is a reduction of the fill light duration of the fill light source with a second reduction amount, wherein the first reduction amount is greater than the second reduction amount; or in response to determining that the exposure state is normal exposure, determine that the first fill light adjustment amount is to keep the fill light duration of the fill light source unchanged.

[0145] In some embodiments, the first brightness distribution in the image is determined based on the brightness distribution of the supplementary lighting region in the image, and wherein the supplementary lighting region in the image is determined by: determining the region in the image containing the specified object as the supplementary lighting region in response to the presence of the specified object in the image, or determining a predetermined region in the image as the supplementary lighting region in response to the absence of the specified object in the image.

[0146] In some embodiments, the first fill light adjustment amount is determined at a first moment among a plurality of moments, and the fill light parameters are determined at each of the plurality of moments to be whether they need to be updated. The update module 430 is further configured to: determine an update condition for the fill light parameters at the first moment based on whether the fill light parameters are changed at a second moment among the plurality of moments, wherein the second moment is prior to the first moment; determine whether the update condition is met based at least on the difference between the first fill light adjustment amount of each camera in at least one camera and a reference fill light adjustment amount; and update the fill light parameters based on the first fill light adjustment amount of each camera in at least one camera in response to the update condition being met.

[0147] In some embodiments, the update module 430 is further configured to: determine a first update condition in response to a change in the fill light parameter at a second time moment; and determine that the first update condition is met in response to a difference between the average of the first fill light adjustment amounts of each camera in at least one camera and a reference fill light adjustment amount greater than a first difference threshold.

[0148] In some embodiments, the update module 430 is further configured to: determine a second update condition in response to the illumination parameter not being changed at a second time; obtain a cumulative difference associated with the second update condition, wherein the cumulative difference indicates the difference between the second illumination adjustment amount of each camera in at least one camera and the reference illumination adjustment amount at a second time; accumulate the difference between the first illumination adjustment amount of each camera in at least one camera and the reference illumination adjustment amount at a first time to a cumulative difference; and determine that the second update condition is met in response to the accumulated difference being greater than a second difference threshold.

[0149] In some embodiments, the difference between the first fill light adjustment amount and the reference fill light adjustment amount is determined by: determining the difference between the first fill light adjustment amount and the reference fill light adjustment amount based on the difference between the average of the first fill light adjustment amounts of each camera in at least one camera and the reference fill light adjustment amount.

[0150] In some embodiments, the updating module 430 is further configured to: update the fill light parameters based on the first fill light adjustment amount of each camera in at least one camera, in response to a first brightness distribution indication in one or more images of at least one image indicating that the ratio of overexposed pixels to total pixels in the corresponding image exceeds a threshold ratio; and determine the update conditions for the fill light parameters at the first time moment based on whether the fill light parameters are changed at the second time moment, in response to a first brightness distribution indication in one or more images of at least one image indicating that the ratio of overexposed pixels to total pixels in the corresponding image does not exceed a threshold ratio.

[0151] In some embodiments, the fill light parameter includes fill light duration, and the first fill light adjustment amount for each camera in at least one camera includes the fill light duration adjustment amount to be performed for the camera. The update module 430 is also configured to update the fill light duration based on the average of the fill light duration adjustment amounts for each camera in at least one camera.

[0152] In some embodiments, the device 400 further includes a fill light switch control module. The switch control module is configured to: for each of the at least one images, determine a first reference illuminance of the image based at least on the relative relationship between a first brightness distribution of the image and the exposure parameters of the camera corresponding to the image when capturing the image; determine a global reference illuminance of the at least one image based on the first reference illuminance of each of the at least one images; and turn on the fill light source in response to the global reference illuminance being less than a first illuminance threshold.

[0153] In some embodiments, the first brightness distribution is determined based on the brightness distribution of the supplementary lighting area in the image. The apparatus 400 also includes a supplementary lighting switch control module. The switch control module is configured to: for each of at least one image, determine a second reference illuminance of the image based on the relative relationship between the second brightness distribution of the image and the exposure parameters of the corresponding camera when capturing the image, wherein the second brightness distribution is determined based on the brightness distribution of areas other than the supplementary lighting area in the image; determine a background reference illuminance of at least one image based on the second reference illuminance of each of the at least one images; and turn off the supplementary lighting source in response to the background reference illuminance being greater than a second illuminance threshold.

[0154] In some embodiments, the apparatus 400 further includes an exposure parameter update module. The exposure parameter update module is configured to: for each of at least one image, determine exposure measurement information of the image based on a first brightness distribution and a second brightness distribution of the image, wherein the first brightness distribution is determined based on the brightness distribution of the illuminated area in the image, and the second brightness distribution is determined based on the brightness distribution of other areas in the image besides the illuminated area; and update the exposure parameters of the camera corresponding to the image based on the difference between the exposure measurement information and the exposure reference information.

[0155] Embodiments of this disclosure also provide a wearable device. The wearable device may be, for example, an XR device such as VR, AR, or MR. The wearable device may be, for example, a helmet, glasses, or other suitable head-mounted display device. In embodiments of this disclosure, the head-mounted device includes at least one camera, a supplementary lighting source, and a controller. The controller includes at least one processor and at least one memory. The at least one memory is coupled to the at least one processor and stores instructions for execution by the at least one processor. These instructions, when executed by the at least one processor, implement various methods or actions of various embodiments of this disclosure to update the supplementary lighting parameters of the supplementary lighting source.

[0156] Figure 5 A block diagram is shown in which a controller 500 may implement one or more embodiments of the present disclosure. The controller 500 may, for example, be used to implement... Figure 1 The controller 114 shown or as Figure 4 The device 400 shown. It should be understood that, Figure 5 The controller 500 shown is merely exemplary and should not be construed as limiting the functionality and scope of the embodiments described herein.

[0157] Reference Figure 5The components of controller 500 may include, but are not limited to, one or more processors 510, memory 520, storage device 530, one or more communication units 540, one or more input devices 550, and one or more output devices 560. Processor 510 may be a physical or virtual processor and is capable of performing various processes based on programs stored in memory 520. In a multiprocessor system, multiple processors execute computer-executable instructions in parallel to improve the parallel processing capability of electronic device 500.

[0158] Electronic device 500 typically includes multiple computer storage media. Such media can be any available media accessible to electronic device 500, including but not limited to volatile and non-volatile media, removable and non-removable media. Memory 520 can be volatile memory (e.g., registers, cache, random access memory (RAM)), non-volatile memory (e.g., read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory), or some combination thereof. Storage device 530 can be removable or non-removable media and can include machine-readable media, such as flash drives, disks, or any other media capable of storing information and / or data and accessible within electronic device 500.

[0159] Electronic device 500 may further include additional removable / non-removable, volatile / non-volatile storage media. Although not explicitly stated... Figure 5 As shown, disk drives for reading from or writing to removable, non-volatile disks (e.g., "floppy disks") and optical disk drives for reading from or writing to removable, non-volatile optical disks can be provided. In these cases, each drive can be connected to a bus (not shown) via one or more data media interfaces. Memory 520 may include computer program product 525 having one or more program modules configured to perform various methods or actions of various embodiments of this disclosure.

[0160] Communication unit 540 enables communication with other electronic devices via a communication medium. Additionally, the functionality of components of electronic device 500 can be implemented using a single computing cluster or multiple computing machines capable of communicating via communication connections. Therefore, electronic device 500 can operate in a networked environment using logical connections to one or more other servers, network personal computers (PCs), or another network node.

[0161] Input device 550 can be one or more input devices, such as a mouse, keyboard, trackball, etc. Output device 560 can be one or more output devices, such as a monitor, speaker, printer, etc. Electronic device 500 can also communicate with one or more external devices (not shown) via communication unit 540 as needed. These external devices include storage devices, display devices, etc., and can communicate with one or more devices that enable user interaction with electronic device 500, or with any device that enables electronic device 500 to communicate with one or more other electronic devices (e.g., network card, modem, etc.). Such communication can be performed via input / output (I / O) interface (not shown).

[0162] According to an exemplary implementation of this disclosure, a computer-readable storage medium is provided that stores computer-executable instructions thereon, wherein the computer-executable instructions are executed by a processor to implement the methods described above. According to an exemplary implementation of this disclosure, a computer program product is also provided, which is tangibly stored on a non-transitory computer-readable medium and includes computer-executable instructions, which are executed by a processor to implement the methods described above.

[0163] Various aspects of this disclosure are described herein with reference to flowchart illustrations and / or block diagrams of methods, apparatuses, devices, and computer program products implemented according to this disclosure. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer-readable program instructions.

[0164] These computer-readable program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine such that, when executed by the processor of the computer or other programmable data processing apparatus, they create means for implementing the functions / actions specified in one or more blocks of the flowchart and / or block diagram. These computer-readable program instructions can also be stored in a computer-readable storage medium that causes a computer, programmable data processing apparatus, and / or other device to operate in a particular manner; thus, the computer-readable medium storing the instructions comprises an article of manufacture that includes instructions for implementing aspects of the functions / actions specified in one or more blocks of the flowchart and / or block diagram.

[0165] Computer-readable program instructions can be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable data processing apparatus, or other device to produce a computer-implemented process, thereby causing the instructions that execute on the computer, other programmable data processing apparatus, or other device to perform the functions / actions specified in one or more boxes of a flowchart and / or block diagram.

[0166] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of an instruction, which contains one or more executable instructions for implementing the specified logical function. In some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0167] Various implementations of this disclosure have been described above. The foregoing description is exemplary and not exhaustive, nor is it limited to the disclosed implementations. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described implementations. The terminology used herein is determined to best explain the principles, practical applications, or improvements to technology in the market, or to enable others skilled in the art to understand the various implementations disclosed herein.

Claims

1. A method for exposure control, comprising: obtaining at least one image captured by at least one camera; for each image of the at least one image, determining an exposure state of a camera corresponding to the image based at least on a first luminance distribution of the image, wherein the exposure state indicates an exposure state of the camera after being supplemented by a supplemental light source associated with the at least one camera when capturing the image; based on the exposure state of the camera, determining a first supplemental light adjustment amount to be performed for the camera; and based on the first supplemental light adjustment amount of each camera of the at least one camera, updating a supplemental light parameter of the supplemental light source.

2. The method of claim 1, wherein determining the exposure state of the corresponding camera comprises: based on the first luminance distribution of the image, determining whether a proportion of overexposed pixels to total pixels in the image exceeds a threshold proportion; in response to determining that the proportion of overexposed pixels to total pixels in the image exceeds the threshold proportion, determining the exposure state of the camera as a first overexposure state; in response to determining that the proportion of overexposed pixels to total pixels in the image does not exceed the threshold proportion, based on the first luminance distribution of the image, determining an average luminance of the image; and based on a relative relationship between the average luminance of the image and an exposure parameter of the camera when capturing the image, determining the exposure state of the camera.

3. The method of claim 2, wherein the exposure parameter of the camera comprises an exposure gain and an exposure duration, and wherein based on the relative relationship between the average luminance of the image and the exposure parameter of the camera, determining the exposure state of the camera comprises: in response to a ratio of the average luminance of the image to a product of the exposure gain and the exposure duration of the camera being higher than a reference ratio range, determining the exposure state of the camera as a second overexposure state, or in response to the ratio of the average luminance of the image to the product of the exposure gain and the exposure duration of the camera being lower than the reference ratio range, determining the exposure state of the camera as an underexposure state, or in response to the ratio of the average luminance of the image to the product of the exposure gain and the exposure duration of the camera being within the reference ratio range, determining the exposure state of the camera as a normal exposure state.

4. The method of claim 1, wherein the exposure state of the camera comprises at least a first overexposure state, a second overexposure state, an underexposure state, or a normal exposure state, and the supplemental light parameter comprises a supplemental light duration; and wherein based on the exposure state of the camera, determining the first supplemental light adjustment amount to be performed for the camera comprises: in response to determining that the exposure state is the underexposure state, determining the first supplemental light adjustment amount as an extension of the supplemental light duration of the supplemental light source, or in response to determining that the exposure state is the first overexposure state, determining the first supplemental light adjustment amount as a shortening of the supplemental light duration of the supplemental light source and a shortening amplitude being a first shortening amplitude, or in response to determining that the exposure state is the second overexposure state, determining the first supplemental light adjustment amount as a shortening of the supplemental light duration of the supplemental light source and a shortening amplitude being a second shortening amplitude. ​ in response to determining that the exposure state is the second overexposure state, determining the first light compensation adjustment amount as a shortening of the light compensation duration of the light compensation light source by a first shortening magnitude, and in response to determining that the exposure state is the normal exposure state, determining the first light compensation adjustment amount as keeping the light compensation duration of the light compensation light source unchanged.

5. The method of claim 1, wherein the first brightness distribution in the image is determined based on a brightness distribution of a light compensation region in the image, and wherein the light compensation region in the image is determined by: in response to a presence of a specified object in the image, determining a region in the image containing the specified object as the light compensation region, or in response to an absence of the specified object in the image, determining a predetermined region in the image as the light compensation region.

6. The method of claim 1, wherein the first light compensation adjustment amount is determined at a first time instance among a plurality of time instances, the light compensation parameter is determined whether to be updated at each time instance among the plurality of time instances, and wherein updating the light compensation parameter of a light compensation light source associated with the at least one camera comprises: determining an update condition for the light compensation parameter at the first time instance based on whether the light compensation parameter is changed at a second time instance among the plurality of time instances, wherein the second time instance is prior to the first time instance; determining whether the update condition is satisfied based at least on a difference between the first light compensation adjustment amount and a reference light compensation adjustment amount for each camera in the at least one camera; and in response to the update condition being satisfied, updating the light compensation parameter based on the first light compensation adjustment amount for each camera in the at least one camera.

7. The method of claim 6, wherein determining the update condition for the light compensation parameter at the first time instance comprises: in response to the light compensation parameter being changed at the second time instance, determining the update condition as a first update condition, and wherein determining whether the update condition is satisfied comprises: in response to a difference between an average of the first light compensation adjustment amount for each camera in the at least one camera and the reference light compensation adjustment amount being greater than a first difference threshold, determining that the first update condition is satisfied.

8. The method of claim 6, wherein determining the update condition for the light compensation parameter at the first time instance comprises: in response to the light compensation parameter not being changed at the second time instance, determining the update condition as a second update condition, and wherein determining whether the update condition is satisfied comprises: obtaining an accumulated difference associated with the second update condition, wherein the accumulated difference indicates a difference between a second light compensation adjustment amount for each camera in the at least one camera at the second time instance and the reference light compensation adjustment amount; accumulating a difference between the first light compensation adjustment amount for each camera in the at least one camera at the first time instance and the reference light compensation adjustment amount to the accumulated difference; and ​ In response to the accumulated accumulated difference being greater than a second difference threshold, determining that the second update condition is satisfied.

9. The method of claim 6, wherein updating the fill light parameter of the fill light source associated with the at least one camera further comprises: in response to the first luminance distribution of one or more images of the at least one image indicating that a proportion of overexposed pixels to total pixels in the corresponding image exceeds a threshold proportion, updating the fill light parameter based on the first fill light adjustment amount of each camera of the at least one camera; and in response to the first luminance distribution of each image of the at least one image indicating that the proportion of overexposed pixels to total pixels in the corresponding image does not exceed the threshold proportion, determining an update condition for the fill light parameter at the first time based on whether the fill light parameter is changed at the second time.

10. The method of claim 1, wherein the fill light parameter comprises a fill light duration, the first fill light adjustment amount of each camera of the at least one camera comprises a fill light duration adjustment amount to be performed for the camera, and wherein updating the fill light parameter of the fill light source associated with the at least one camera comprises: updating the fill light duration based on an average of the fill light duration adjustment amount of each camera of the at least one camera.

11. The method of claim 1, further comprising: for each image of the at least one image, determining a first reference illuminance of the image based at least on a relative relationship between the first luminance distribution of the image and an exposure parameter of the camera corresponding to the image when capturing the image; determining a global reference illuminance of the at least one image based on the first reference illuminance of each image of the at least one image; and in response to the global reference illuminance being less than a first illuminance threshold, turning on the fill light source.

12. The method of claim 1, wherein the first luminance distribution is determined based on a luminance distribution of a fill light region in the image, and the method further comprises: for each image of the at least one image, determining a second reference illuminance of the image based on a relative relationship between a second luminance distribution of the image and an exposure parameter of the camera corresponding to the image when capturing the image, wherein the second luminance distribution is determined based on a luminance distribution of a region other than the fill light region in the image; determining a background reference illuminance of the at least one image based on the second reference illuminance of each image of the at least one image; and in response to the background reference illuminance being greater than a second illuminance threshold, turning off the fill light source.

13. The method of claim 1, the method further comprising: for each image of the at least one image, determining exposure measurement information of the image based on the first luminance distribution and a second luminance distribution of the image, wherein the first luminance distribution is determined based on a luminance distribution of a fill light region in the image, and the second luminance distribution is determined based on a luminance distribution of a region other than the fill light region in the image; and updating an exposure parameter of a camera corresponding to the image based on a difference between the exposure measurement information and exposure reference information.

14. An apparatus for exposure control, comprising: an obtaining module configured to obtain at least one image captured by at least one camera; an adjustment amount determining module configured to determine, for each image of the at least one image, an exposure state for a camera corresponding to the image based on at least a first luminance distribution of the image, wherein the exposure state indicates an exposure state of the camera after being supplemented with light by a light supplement source associated with the at least one camera when capturing the image; determine a first light supplement adjustment amount to be performed for the camera based on the exposure state of the camera; and an updating module configured to update a light supplement parameter of the light supplement source based on the first light supplement adjustment amount of each camera of the at least one camera.

15. A wearable device, comprising: at least one camera; a light supplement source; at least one processor; and at least one memory, wherein the at least one memory is coupled to the at least one processor and stores instructions for execution by the at least one processor, the instructions, when executed by the at least one processor, implement a method recited in any one of claims 1 to 13 to update a light supplement parameter of the light supplement source.

16. A computer-readable storage medium having computer-executable instructions stored thereon, the computer-executable instructions executable by a processor to implement a method recited in any one of claims 1 to 13.

17. A computer program product comprising computer-executable instructions, wherein the computer-executable instructions, when executed by a processor, implement a method recited in any one of claims 1 to 13. ​ ​

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