Lighting control for multi-viewpoint image capture

Abstract

An electronic device and method for lighting control for multi-perspective image capture are provided. The electronic device selects a sequence of lighting patterns from a predetermined plurality of lighting patterns for capturing a sequence of images of a subject. The electronic device controls a lighting system to illuminate the subject with a first pulse and a second pulse. The illumination intensity increases from a first intensity to a second intensity associated with the first pulse and the second pulse, respectively. The electronic device controls the lighting system to illuminate the subject with flash pulses corresponding to the selected sequence of lighting patterns based on the illumination of the subject with the first pulse and the second pulse. The electronic device controls a sequence of multi-perspective image capture devices to capture a sequence of images of the subject based on the illumination of the subject with the selected sequence of flash pulses.

Description

[Technical Field]

[0001] Cross-reference to related applications / incorporation by reference This application claims the benefit of priority to U.S. Patent Application No. 17 / 986,183, filed with the United States Patent and Trademark Office on November 14, 2022. The above application is incorporated herein by reference in its entirety.

[0002] Various embodiments of the present disclosure relate to imaging technology, and more particularly, to electronic devices and methods for controlling lighting systems for image capture using multi-view image capture devices. [Background technology]

[0003] Advances in the field of imaging technology have led to the development of image capture devices capable of capturing high-fidelity images based on various settings in different lighting environments. In various scenarios, a lighting system may be used in conjunction with the imaging system to illuminate the object to be captured. The lighting system may need to be synchronized with the imaging system to capture high-fidelity images of the object. The synchronization process may be a critical task, especially when high-fidelity images of an object need to be captured under various lighting conditions or when high-fidelity scans of the object need to be obtained. This may be because lighting conditions may affect the imaging quality (i.e., signal-to-noise ratio), sensitivity, low-light performance, and robustness of the image capture device to object movement during imaging. Therefore, maintaining synchronization between the lighting device and the imaging device under different lighting conditions may be tedious.

[0004] Furthermore, images captured using an imaging system may have a shallow depth of field. For example, if the subject is a person and the person's head (i.e., face) needs to be captured, the entire head may not be in focus during capture. To mitigate the shallow depth of field issue, manual focus adjustment may be required before capture. However, manual focus adjustment may affect the quality of the captured image or the speed and accuracy of the scan, especially if the subject is moving during capture. Furthermore, due to the use of focus-by-wire technology, the manually set focus may be lost when the imaging system is turned off or restarted. Summary of the Invention

[0005] The limitations and disadvantages of conventional approaches will become apparent to those skilled in the art by comparing the described system with certain aspects of the present disclosure illustrated in the remainder of this application and with reference to the drawings.

[0006] Provided are electronic devices and methods for controlling a lighting system for image capture using a multi-viewpoint image capture device substantially as shown and / or described in connection with at least one of the figures and more fully set forth in the claims.

[0007] These and other features and advantages of the present disclosure will become apparent from a consideration of the following detailed description of the disclosure when taken in conjunction with the accompanying drawings, in which like reference characters refer to like elements throughout. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 illustrates an exemplary network environment for controlling a lighting system for image capture using a series of multi-view image capture devices, according to an embodiment of the present disclosure. [Figure 2]2 is a block diagram illustrating the example electronic device of FIG. 1 for controlling an illumination system and a series of multi-perspective image capture devices for capturing a series of images of a subject, according to an embodiment of the present disclosure. [Figure 3] FIG. 1 illustrates an exemplary environment for capturing images of a subject illuminated by a series of lighting patterns using a series of multi-view image capture devices, according to an embodiment of the present disclosure. [Figure 4] FIG. 1 illustrates an exemplary execution pipeline for controlling a lighting system for image capture using a series of multi-view image capture devices, according to an embodiment of the present disclosure. [Figure 5A] FIG. 2 is a first exemplary timing diagram illustrating synchronization between an illumination system and a series of multi-view image capture devices for image capture in single-shot mode, according to an embodiment of the present disclosure. [Figure 5B] FIG. 10 is a second exemplary timing diagram illustrating synchronization between an illumination system and a series of multi-view image capture devices for burst mode image capture, according to an embodiment of the present disclosure. [Figure 6] 1 is a flowchart illustrating operations of an exemplary method for controlling a lighting system for image capture using a multi-view image capture device, according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0009] The disclosed electronic device and method for controlling a lighting system for image capture using a multi-perspective image capture device may include the following embodiments. An exemplary aspect of the present disclosure provides an electronic device (e.g., a computing device, desktop, laptop, or personal computer) capable of controlling a lighting system to illuminate a subject and a series of multi-perspective image capture devices to capture a series of images of the subject. The electronic device may select a series of lighting patterns from a plurality of predetermined lighting patterns (e.g., omni-directional lighting patterns or gradient lighting patterns) for capturing the series of images of the subject. The electronic device may control a lighting system associated with the electronic device to illuminate the subject with a first series of flash pulses including a first pulse and a second pulse. The illumination intensity of the first series of flash pulses may increase from a first intensity associated with the first pulse to a second intensity associated with the second pulse. The first intensity associated with the first pulse may be lower than the second intensity associated with the second pulse. Additionally, the electronic device may control the lighting system to illuminate the subject with a second series of flash pulses based on the illumination of the subject with the first series of flash pulses. The second series of flash pulses may correspond to a selected series of lighting patterns. The illumination intensity of each of the second series of flash pulses may correspond to a second intensity. Additionally, the electronic device may control a series of multi-perspective image capture devices associated with the electronic device to capture each of a series of images of the subject based on the illumination of the subject with the second series of flash pulses.

[0010] An image capture device can be controlled to capture an image of a subject illuminated by a lighting system. When an image needs to be captured in a dark environment, the lighting system can trigger a flash pulse to illuminate the subject. Typically, the lighting system can emit a pulse of an intensity that can cause the subject to react instantaneously to a sudden change in the subject's ambient lighting conditions (i.e., from dark to bright). The image capture device can capture this subject's reaction. Therefore, if the subject has not adapted to the ambient lighting conditions, user comfort and image quality may be compromised. Furthermore, the flash pulse triggered by the lighting system can correspond to typical lighting patterns. However, obtaining high-fidelity three-dimensional (3D) facial geometry and material scans may require careful and heuristic selection of lighting patterns. Existing image capture systems may not be able to control the lighting system to trigger a flash pulse that corresponds to an appropriate lighting pattern based on such requirements.

[0011] Typically, lighting systems may not be able to trigger flash pulses in synchronization with the opening and closing of the shutter of the image capture device. For example, the shutter speed may not be able to be adjusted or controlled relative to the triggering of flash pulses by the lighting system. Failure to coordinate flash pulse triggering with shutter speed can result in missed frames (due to low shutter speeds) and missed flash pulses (due to high shutter speeds). For example, flash pulses may be lost if the duration of the flash pulse is such that the flash pulse remains on while the shutter is closed.

[0012] Typically, the characteristics of one or more sensors in an image capture device can affect the depth of field. For example, an 85mm lens with a 35mm sensor and an aperture of f / 9 may only focus half of a subject's head when capturing an image of the subject to obtain a 3D head model. One or more lenses in an image capture device may employ focus-by-wire technology to capture an image of the subject. Therefore, a user (e.g., a photographer) may need to manually set or adjust the focus before capturing an image. The need for manual focus adjustment increases the sensitivity of the imaging system to slight movements of the subject during image capture. For example, movement of the subject's head during image capture can result in various types of degradation, such as blurring, degradation of captured image quality, inaccurate estimation of the subject's 3D model, and underestimation of reflectance components. Furthermore, each time the image capture device is turned off or restarted, it may be necessary to refocus one or more lenses in the image capture device.

[0013] To address these issues, the disclosed electronic device can control a lighting system or a series of multi-perspective image capture devices to select a series of lighting patterns. The electronic device can control the intensity and polarization of light emitted by one or more light sources of the lighting system to generate the selected series of lighting patterns. The multi-perspective image capture devices can be controlled to capture images of a subject illuminated with the selected series of lighting patterns. The captured images of the subject based on illuminating the subject with the selected series of lighting patterns can be used for high-fidelity three-dimensional (3D) facial scanning and accurate estimation of 3D geometry (e.g., facial geometry). Furthermore, the captured images can be used for high-quality reconstruction of facial geometry and texture, or for accurately performing a material scan (e.g., a scan of facial material) of the subject (illuminated with the selected series of lighting patterns). The material scan can be used to estimate material properties of skin and generate a photorealistic 3D representation of the subject's head (or face). Furthermore, the electronic device can control the lighting system to trigger flash pulses of various intensities, and can trigger a low-intensity flash pulse followed by a high-intensity flash pulse. Triggering a series of flash pulses in this manner can prevent the subject from being exposed to sudden or rapid changes in the intensity of the flash pulses.

[0014] The disclosed electronic device can further control the autofocus settings of the image capture devices of the series of multi-perspective image capture devices before capturing an image of the subject. The autofocus settings can also be controlled before capturing an image of the subject if there is a change in the detected facial expression or emotion expressed by the subject or if there is a change in the lighting pattern used to illuminate the subject. Controlling the autofocus can ensure that movement of the subject during image capture does not affect the accuracy of the 3D facial or material scan. Furthermore, the electronic device can set the shutter speed of each image capture device of the series of multi-perspective image capture devices to an optimal value for capturing images in both single-shot and burst modes. In single-shot mode, the electronic device can perform a 3D facial scan and determine a 3D color texture. In burst mode, the electronic device can further determine multiple textures (including color structures).

[0015] FIG. 1 illustrates an exemplary network environment for controlling a lighting system for image capture using an array of multi-perspective image capture devices, according to an embodiment of the present disclosure. Network environment 100 is shown in FIG. 1. Network environment 100 includes an electronic device 102, a lighting system 104, an array of multi-perspective image capture devices 106, and a server 108. In at least one embodiment, lighting system 104 may include light source 104A, light source 104B, ..., and light source 104N. In at least one embodiment, array of multi-perspective image capture devices 106 may include image capture device 106A, image capture device 106B, ..., and image capture device 106N. In at least one embodiment, server 108 may include database 110. Electronic device 102 may communicate with lighting system 104, array of multi-perspective image capture devices 106, and / or server 108 over one or more networks (e.g., communication network 112). Also shown is a subject 114 associated with lighting system 104 and multi-perspective image capture devices 106. The electronic device 102 can control the illumination system 104 to illuminate the subject 114 with flash pulses. The electronic device 102 can control the series of multi-view image capture devices 106 to capture images of the subject 114.

[0016] The N light sources and N image capture devices shown in Figure 1 are provided by way of example only. Illumination system 104 and array of multi-perspective image capture devices 106 may each include only one light source and more than N image capture devices without departing from the scope of this disclosure. For simplicity, Figure 1 shows only N light sources (in illumination system 104) and N image capture devices (in array of multi-perspective image capture devices 106).

[0017] The electronic device 102 may include suitable logic, circuitry, interfaces, and / or code configurable to control the lighting system 104 to trigger flash pulses corresponding to omni-directional lighting patterns and spherical gradient lighting patterns. The electronic device 102 may select from a series of lighting patterns including cross-polarized or parallel-polarized omni-directional lighting patterns and cross-polarized or parallel-polarized spherical gradient lighting patterns. The electronic device 102 may control the lighting system 104 to illuminate the object 114 with flash pulses. The electronic device 102 may control the series of multi-perspective image capture devices 106 to capture images of the object 114 based on the illumination of the object 114 with flash pulses corresponding to the omni-directional lighting patterns or the spherical gradient lighting patterns. Examples of the electronic device 102 may include, but are not limited to, a desktop, a tablet, a laptop, a computing device, a smartphone, a cellular phone, a mobile phone, a control device with an image sensor and a lighting system, or a consumer electronics (CE) device having a display.

[0018] The lighting system 104 may include suitable logic, circuitry, interfaces, and / or code that can be configured to illuminate the object 114 with flash pulses. The lighting system 104 may include multiple light sources (e.g., light source 104A, light source 104B, ..., and light source 104N). In at least one embodiment, each light source of the multiple light sources may correspond to an electronically controlled lighting fixture. The multiple light sources may be spatially arranged in the environment to illuminate the object 114 with flash pulses from the left side of the object 114, the right side of the object 114, above the object 114, below the object 114, in front of the object 114, or behind the object 114. Each light source of the multiple light sources may include one or more polarizers (i.e., polarizing filters). The one or more polarizers may linearly polarize the light emitted by the light source (e.g., horizontally or vertically). In at least one embodiment, each of the multiple light sources can include circular polarizers that can convert linearly polarized light into cross-polarized or parallel polarized illumination patterns. Examples of each of the multiple light sources can include, but are not limited to, an incandescent lamp, a halogen lamp, a light-emitting diode (LED) lamp, a metal halide lamp, a low-pressure sodium lamp, a fluorescent lamp / tube, a high-intensity discharge lamp, or a neon lamp. In some embodiments, the illumination system 104 can accommodate a light cage arrangement (e.g., a light stage) that can be positioned around the subject 114 to illuminate the subject 114 from various angles / directions based on trigger pulses.

[0019] The array of multi-perspective image capture devices 106 may include suitable logic, circuitry, interfaces, and / or code that may be configured to capture a series of images of the object 114 based on illumination of the object 114 by the illumination system 104. The array of multi-perspective image capture devices 106 may include multiple image capture devices (e.g., image capture device 106A, image capture device 106B, ..., and image capture device 106N). In some embodiments, the array of multi-perspective image capture devices 106 may capture a 360-degree view of the object 114. Each image capture device in the array of multi-perspective image capture devices 106 may be configured to capture a portion of the 360-degree view of the object 114. In some embodiments, the 360-degree view of the object 114 may be used to generate a three-dimensional (3D) scan of the object 114. The lens of each image capture device may be coupled to a circular polarizing filter. The circular polarizing filter may receive horizontally or vertically polarized light to generate a cross-polarized or parallel-polarized (omnidirectional or spherically gradient) illumination pattern. In at least one embodiment, each image capture device in the array of multi-perspective image capture devices 106 can be a high-resolution still camera with burst capabilities. The image capture devices in the array of multi-perspective image capture devices 106 can capture fine skin details to generate high-resolution meshes and textures. Additionally, the image capture devices can have high bit depths (e.g., an image capture device can generate 14-bit RAW files for high dynamic range (HDR) textures). The image capture devices can provide optimal low-light performance and have low sensor noise. Examples of each image capture device can include, but are not limited to, an image sensor, a wide-angle camera, an action camera, a closed-circuit television (CCTV) camera, a camcorder, a digital camera, a camera phone, a time-of-flight camera (ToF camera), a night vision camera, and / or other image capture devices.

[0020] The server 108 may include suitable logic, circuitry, interfaces, and / or code that may be configured to receive a series of captured images of the subject 114 from the electronic device 102. In at least one embodiment, the server 108 may determine a 3D facial geometry associated with the subject 114 based on the captured images of the subject 114 to construct a photorealistic, relightable model of the subject's 114 head. The 3D geometry may be determined based on information extracted from the captured images of the subject 114. The server 108 may be configured to perform (face) shape reconstruction or separation between diffuse and specular reflection components based on illumination of the subject 114 with a selected series of lighting patterns (e.g., cross-polarized or parallel-polarized omnidirectional lighting patterns). The diffuse and specular reflection components may correspond to light reflected from a facial surface associated with the subject 114 and captured by the series of multi-view image capture devices 106. The server 108 may be further configured to generate normal and height maps based on illumination of the object 114 with a selected set of lighting patterns (e.g., cross-polarized or parallel-polarized spherical gradient lighting patterns). The server 108 may perform operations through web applications, cloud applications, HTTP requests, repository operations, file transfers, and the like. Example implementations of the server 108 may include, but are not limited to, a database server, a file server, a web server, an application server, a mainframe server, a cloud computing server, or combinations thereof.

[0021] In at least one embodiment, server 108 may be implemented as multiple distributed cloud-based resources using multiple techniques known to those skilled in the art. Those skilled in the art will appreciate that the scope of the present disclosure may not be limited to the implementation of server 108 and electronic device 102 as two separate entities. In some embodiments, the functionality of server 108 may be incorporated, in whole or at least in part, into electronic device 102 without departing from the scope of the present disclosure.

[0022] The database 110 may include suitable logic, interfaces, and / or code that can be configured to store a series of images of a subject 114 captured by a series of multi-perspective image capture devices 106. The database 110 may be derived from data from a relational or non-relational database, or from a comma-separated values ​​(csv) file set in traditional storage or big data storage. The database 110 may be stored or cached on a device, such as the electronic device 102 or the server 108. In some embodiments, the database 110 may be hosted on multiple servers or devices in the same or different locations. The operations of the database 110 may be performed using hardware, including a processor, a microprocessor (e.g., that performs or controls the execution of one or more operations), a field programmable gate array (FPGA), or an application-specific integrated circuit (ASIC). In some other cases, the database 110 may be implemented using software.

[0023] The communication network 112 may include a communication medium that enables the electronic device 102, the lighting system 104, the array of multi-perspective image capture devices 106, and the server 108 to communicate with one another. The communication network 112 may be a wired or wireless communication network. Examples of the communication network 112 may include, but are not limited to, the Internet, a cloud network, a cellular or wireless mobile network (such as Long Term Evolution and Fifth Generation (5G) New Radio (NR)), a satellite communication system (e.g., using low-earth orbit satellites), a Wireless Fidelity (Wi-Fi) network, a personal area network (PAN), a local area network (LAN), or a metropolitan area network (MAN). The various devices in the network environment 100 may be configured to connect to the communication network 112 according to various wired and wireless communication protocols. Examples of such wired and wireless communication protocols include, but are not limited to, at least one of Transmission Control Protocol and Internet Protocol (TCP / IP), User Datagram Protocol (UDP), Hypertext Transfer Protocol (HTTP), File Transfer Protocol (FTP), ZigBee, EDGE, IEEE802.11, Light Fidelity (Li-Fi), 802.16, IEEE802.11s, IEEE802.11g, multi-hop communication, wireless access point (AP), device-to-device communication, cellular communication protocols, and Bluetooth (BT) communication protocols.

[0024] In operation, the electronic device 102 can be configured to select a sequence of illumination patterns from a plurality of predefined illumination patterns for capturing an image of the object 114. According to an embodiment, the electronic device 102 can receive user input indicating a selection of the sequence of illumination patterns from the plurality of predefined illumination patterns. The object 114 can be illuminated with the selected sequence of illumination patterns via flash pulses. According to an embodiment, the plurality of predefined illumination patterns can include an omnidirectional illumination pattern, a directional illumination pattern, a cross-polarized illumination pattern, and a parallel-polarized illumination pattern. The sequence of illumination patterns selected from the plurality of predefined illumination patterns can be categorized into a first sequence of illumination patterns and a second sequence of illumination patterns. The first sequence of illumination patterns can include a cross-polarized omnidirectional illumination pattern and a parallel-polarized omnidirectional illumination pattern. The second sequence of illumination patterns can include a cross-polarized spherical gradient illumination pattern and a parallel-polarized spherical gradient illumination pattern.

[0025] According to one embodiment, this classification may be based on information that can be extracted based on illumination of the subject 114 with flash pulses corresponding to the selected set of lighting patterns. The extracted information may include facial skin-related details, a high-resolution 3D face mesh (i.e., 3D face geometry), a high-resolution face texture map, material properties related to facial skin, facial diffuse reflectance components, specular reflectance components, normal maps, and height maps. Details of selecting the set of lighting patterns from a plurality of predetermined lighting patterns may be further described, for example, in Figures 3 and 4 (402).

[0026] The electronic device 102 may be further configured to control an illumination system 104 associated with the electronic device 102 to illuminate the object 114 with a first series of flash pulses including a first pulse and a second pulse. The illumination intensity of the first series of flash pulses may increase from a first intensity to a second intensity. The first intensity may be associated with the first pulse, and the second intensity may be associated with the second pulse. The first intensity may be lower than the second intensity. According to some embodiments, the first pulse may correspond to modeling light, and the first intensity may correspond to a predetermined intensity. According to some embodiments, the electronic device 102 may control the illumination system 104 to illuminate the object 114 with a first pulse having a lower intensity. Thereafter, the illumination system 104 may illuminate the object 114 with a second pulse having a higher intensity. By gradually increasing the illumination intensity from a first intensity (i.e., a lower intensity) associated with a first pulse to a second intensity (i.e., a higher intensity) associated with a second pulse, the subject 114 is allowed to adapt to the second intensity (i.e., the higher intensity).

[0027] Acclimatization is necessary because the subject 114 may be illuminated with flash pulses corresponding to a second intensity to capture an image of the subject 114. Acclimatization can prevent the subject 114 from being exposed to sudden changes in light intensity, which may be uncomfortable for the subject 114. For example, if the subject 114 has not adapted to the second intensity, the sudden triggering of a second pulse at the second intensity may cause the subject 114 to voluntarily or unconsciously close their eyes. Illuminating the subject 114 with a first pulse at a first intensity before illuminating the subject 114 with a second pulse at a second intensity can ensure eye comfort for the subject 114. Details of the control of the illumination system 104 to illuminate the subject 114 with the first series of flash pulses are further described, for example, in FIGS. 3 and 4 (404).

[0028] The electronic device 102 may be further configured to control the lighting system 104 to illuminate the subject 114 with a second series of flash pulses based on the illumination of the subject 114 with the first series of flash pulses. According to an embodiment, the second series of flash pulses may correspond to a selected series of lighting patterns. The selected series of lighting patterns may correspond to at least one of, but not limited to, the first series of lighting patterns or the second series of lighting patterns. The second series of flash pulses corresponding to a first series of lighting patterns (i.e., a cross-polarized or parallel-polarized omnidirectional lighting pattern) of the selected series of lighting patterns may be used for shape (e.g., facial shape or geometry) reconstruction or separation of diffuse and specular reflectance components. The illumination intensity of each flash pulse of the second series of flash pulses corresponding to the first series of lighting patterns may be equal to the second intensity.

[0029] According to an embodiment, the electronic device 102 can control the illumination system 104 to illuminate the object 114 with a second series of flash pulses corresponding to a second series of illumination patterns (i.e., a cross-polarized or parallel-polarized spherical gradient illumination pattern). The electronic device 102 can control the illumination intensity associated with the second series of flash pulses based on the position of a light source in the illumination system 104 that triggers the second series of flash pulses and the particular spherical gradient illumination pattern of the second series of illumination patterns used to illuminate the object 114. The second series of flash pulses corresponding to the second series of illumination patterns (i.e., a cross-polarized or parallel-polarized spherical gradient illumination pattern) of the selected series of illumination patterns can be used for normal map generation and height map generation.

[0030] In some embodiments, electronic device 102 can control illumination system 104 to illuminate object 114 with a second series of flash pulses corresponding to vertically polarized illumination or horizontally polarized illumination. The second series of flash pulses corresponding to vertically polarized illumination can be transformed into a cross-polarized omnidirectional illumination pattern or a cross-polarized spherical gradient illumination pattern. Similarly, the second series of flash pulses corresponding to horizontally polarized illumination can be transformed into a parallel-polarized omnidirectional illumination pattern or a parallel-polarized spherical gradient illumination pattern. Details of controlling illumination system 104 to illuminate object 114 with the second series of flash pulses are further described, for example, in FIGS. 3 and 4 (406).

[0031] The electronic device 102 may be further configured to control the series of multi-perspective image capture devices 106 associated with the electronic device 102 to capture images of the subject 114 based on the illumination of the subject 114 with the second series of flash pulses. For example, the selected series of lighting patterns may include 11 lighting patterns. The electronic device 102 may capture a series of images for each lighting pattern (i.e., the subject 114 illuminated with the lighting pattern). All image capture devices (e.g., image capture device 106A) in the series of multi-perspective image capture devices 106 may simultaneously capture images in each series of images. The number of images in each series of images may be based on the number of image capture devices in the series of multi-perspective image capture devices 106. For example, if the series of multi-perspective image capture devices 106 includes six image capture devices, the series of images captured for each lighting pattern may include six images (captured simultaneously). Thus, in such a case, the electronic device 102 may capture six images for each lighting pattern. Therefore, since the electronic device 102 can capture "6" images for each of the "11" selected lighting patterns (i.e., it can capture "6" images for each lighting pattern), the second series of flash pulses can include "66" (i.e., 6*11=66) flash pulses.

[0032] According to one embodiment, the series of multi-perspective image capture devices 106 can capture each of the series of images based on receiving a second series of flash pulses corresponding to a selected series of illumination patterns reflected from a surface (e.g., skin) of the subject 114. According to another embodiment, the series of multi-perspective image capture devices 106 can capture each of the series of images based on receiving reflected light corresponding to vertically polarized illumination or horizontally polarized illumination. The series of multi-perspective image capture devices 106 can convert a vertically polarized illumination pattern or a horizontally polarized illumination pattern into a cross-polarized illumination pattern or a parallel-polarized (omnidirectional or spherically gradient) illumination pattern based on capturing each of the series of images.

[0033] The electronic device 102 may be further configured to generate a photorealistic, relightable head model associated with the subject 114 based on a series of captured images of the subject 114. The electronic device 102 may determine (using each of the series of captured images) facial skin-related details, extract a high-resolution 3D face mesh (3D face geometry), generate a high-resolution facial texture map, perform facial shape reconstruction, estimate material properties associated with the facial skin, separate diffuse and specular reflectance components of the face, generate a normal map and a height map, etc. The photorealistic, relightable head model may be generated based on one or more of the facial skin details, the 3D face mesh, the facial texture map, the material properties associated with the facial skin, the separation of diffuse and specular reflectance, or the normal map and height map. Details of controlling the series of multi-view image capture devices 106 to capture images of the subject 114 are further described, for example, in FIGS. 3 and 4 (408).

[0034] Figure 2 is a block diagram illustrating the example electronic device of Figure 1 for controlling a lighting system and a series of multi-perspective image capture devices for capturing a series of images of a subject, in accordance with an embodiment of the present disclosure. The description of Figure 2 is provided with reference to the elements of Figure 1. Figure 2 illustrates a block diagram 200 of an electronic device 102. The electronic device 102 may include circuitry 202, memory 204, input / output (I / O) devices 206, a network interface 208, a lighting system 104, and a series of multi-perspective image capture devices 106. In at least one embodiment, the I / O devices 206 may also include a display device 210. The circuitry 202 may be communicatively coupled to the memory 204, the I / O devices 206, the network interface 208, the lighting system 104, and the series of multi-perspective image capture devices 106 via wired or wireless communication with the electronic device 102.

[0035] The circuit 202 may include suitable logic, circuits, and interfaces configurable to execute program instructions associated with different operations performed by the electronic device 102. These operations may include selecting a sequence of lighting patterns from a plurality of predetermined lighting patterns for capturing a sequence of images of the object 114. The operations may further include controlling the lighting system 104 associated with the electronic device 102 to illuminate the first object 114 with a sequence of flash pulses including a first pulse and a second pulse. The operations may further include controlling the lighting system 104 to illuminate the second object 114 with flash pulses corresponding to the selected sequence of lighting patterns based on the illumination of the object 114 with the first sequence of flash pulses. The operations may further include controlling the set of multi-perspective image capture devices 106 associated with the electronic device 102 to capture each of the sequence of images of the object 114 based on the illumination of the object 114 with the second flash pulses. The circuit 202 may include one or more specialized processing units, which may be implemented as an integrated processor or group of processors that collectively perform the functions of the one or more specialized processing units. The circuit 202 can be implemented based on multiple processor technologies known in the art, and example implementations of the circuit 202 can be an X86-based processor, a graphics processing unit (GPU), a reduced instruction set computing (RISC) processor, an application specific integrated circuit (ASIC) processor, a complex instruction set computing (CISC) processor, a microcontroller, a central processing unit (CPU), and / or other computing circuitry.

[0036] The memory 204 may include suitable logic, circuits, interfaces, and / or code that may be configured to store program instructions executed by the circuit 202. The program instructions stored in the memory 204 may enable the circuit 202 to perform the operations of the circuit 202 (and / or the electronic device 102). In at least one embodiment, the memory 204 may store images of the subject 114 captured by a series of multi-perspective image capture devices 106. The memory 204 may also store information related to a selected lighting pattern (e.g., an omnidirectional or spherical gradient lighting pattern, which may be cross-polarized or parallel-polarized) for capturing the series of images. The memory 204 may further store a determined 3D geometry of the head (face) of the subject 114, a material scan (i.e., a scan of the facial skin material), or characteristics (e.g., reflectance or scattering) associated with the facial skin. The memory 204 may store a photorealistic, reilluminatable model (of the head) of the subject 114 derived based on the 3D geometry and material scan. Examples of implementations of memory 204 include, but are not limited to, random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), hard disk drive (HDD), solid state drive (SSD), CPU cache, and / or secure digital (SD) cards.

[0037] The I / O device 206 may include suitable logic, circuitry, interfaces, and / or code that can be configured to receive input and provide output based on the received input. For example, the I / O device 206 may receive user input related to selecting a sequence of lighting patterns from a plurality of predetermined lighting patterns. The I / O device 206 may further receive user input indicating a command (to the lighting system 104) to trigger a first sequence of flash pulses and a second sequence of flash pulses (to illuminate the subject 114). The I / O device 206 may further receive user input indicating a command (to the sequence of multi-perspective image capture devices 106) to capture images of the subject 114 based on the illumination of the subject 114 with the second flash pulses. The I / O device 206 may further receive user input indicating that the first sequence of images has been captured based on the illumination of the subject 114 with one of the sequence of lighting patterns. In some embodiments, the I / O device 206 may receive user input indicating a command to generate a photorealistic reilluminatable model of the face (head) of the subject 114. Examples of I / O devices 206 include, but are not limited to, a touch screen, a keyboard, a mouse, a joystick, a microphone, a display device 212, and a speaker. Examples of I / O devices 206 may further include Braille I / O devices, such as Braille keyboards and Braille readers.

[0038] The I / O devices 206 may include a display device 210. The display device 210 may include suitable logic, circuitry, and interfaces configurable to receive input from the circuit 202 for rendering the captured image of the subject 114 on a display screen. The display device 210 may further be configured to render parameters determined based on the captured image of the subject 114. According to an embodiment, the display device 210 may be configured to render a photorealistic, re-illuminatable model of the head of the subject 114. In at least one embodiment, the display screen may be at least one of a resistive touch screen, a capacitive touch screen, or a thermal touch screen. The display device 210 or display screen may be implemented through several known technologies, such as, but not limited to, at least one of a liquid crystal display (LCD) display, a light emitting diode (LED) display, a plasma display, or an organic LED (OLED) display technology, or other display devices.

[0039] The network interface 208 may include suitable logic, circuits, and interfaces that may be configured to facilitate communication between the circuitry 202, the lighting system 104, the array of multi-perspective image capture devices 106, and the server 108 over the communications network 112. The network interface 208 may be implemented using various known technologies to support wired or wireless communications between the electronic device 102 and the communications network 112. The network interface 208 may include, but is not limited to, an antenna, a radio frequency (RF) transceiver, one or more amplifiers, a tuner, one or more oscillators, a digital signal processor, a coder-decoder (CODEC) chipset, a subscriber identity module (SIM) card, or a local buffer circuit.

[0040] The network interface 208 may be configured to communicate via wireless communication with a network such as the Internet, an intranet, or a wireless network such as a cellular telephone network, a wireless local area network (LAN), a local area network, or a metropolitan area network (MAN). The wireless communication may use one or more of a number of communication standards, protocols, and technologies, such as Global System for Mobile Communications (GSM), Enhanced Data GSM Environment (EDGE), Wideband Code Division Multiple Access (W-CDMA), Long Term Evolution (LTE), Fifth Generation (5G) New Radio (NR), Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Bluetooth, Wireless Fidelity (WiFi) (such as IEEE 802.11a, IEEE 802.11b, IEEE 802.11g, or IEEE 802.11n), Voice over Internet Protocol (VoIP), Light Fidelity (Li-Fi), Worldwide Interoperability for Microwave Access (Wi-MAX), short-range communications protocols, and wireless peer-to-peer protocols.

[0041] The functions or operations performed by electronic device 102 as described in Figure 1 may be performed by circuitry 202. The operations performed by circuitry 202 are described in detail in, for example, Figures 3, 4, 5A, and 6.

[0042] FIG. 3 illustrates an exemplary environment for capturing images of a subject illuminated by a series of lighting patterns using a series of multi-perspective image capture devices, according to an embodiment of the present disclosure. The description of FIG. 3 is provided with reference to elements of FIGS. 1 and 2. FIG. 3 illustrates an exemplary environment 300. The exemplary environment 300 can be an indoor or outdoor environment that can be used by a photographer or professional associated with a creative industry (such as the gaming or film industry) to capture images of a subject seated on a platform (e.g., a chair) within the exemplary environment 300. In some embodiments, the captured images can be used to generate a photorealistic, re-illuminatable model of the subject's head seated on the platform. FIG. 3 illustrates a subject 306 within the environment 300. The subject 306 can be illuminated by a series of light sources (e.g., as indicated by light sources 302A...302F) for capturing images using a series of image capture devices (e.g., as indicated by image capture devices 304A...304F).

[0043] For example, environment 300 illustrates a lighting system including a series of light sources, 302A, 302B, 302C, 302D, 302E, and 302F (hereinafter, 302A...302F). The series of light sources 302A...302F can be exemplary implementations of light sources 104A...104N. The functionality of the series of light sources 302A...302F can be identical to the functionality of light sources 104A...104N. In one example, light source 302A can trigger a flash pulse that illuminates subject 306 from the left side of subject 306. Light source 302B can trigger a flash pulse that illuminates subject 306 from the right side of subject 306. Furthermore, light source 302C can trigger a flash pulse that illuminates subject 306 from above subject 306, and light source 302D can trigger a flash pulse that illuminates subject 306 from below subject 306. Similarly, light source 302E can trigger a flash pulse that illuminates subject 306 from the front side of subject 306, and light source 302F can trigger a flash pulse that illuminates subject 306 from the back side of subject 306.

[0044] Also shown are a series of image capture devices, namely, 304A, 304B, 304C, 304D, 304E, and 304F (hereinafter, 304A...304F). The series of image capture devices 304A...304F may be exemplary implementations of image capture devices 106A...106N. The functionality of the series of image capture devices 304A...304F may be identical to the functionality of image capture devices 106A...106N. Image capture device 304A may capture a left view of object 306. Image capture device 304B may capture a right view of object 306. Furthermore, image capture device 304C may capture an upper view of object 306, and image capture device 304D may capture a lower view of object 306. Similarly, image capture device 304E can capture a front view of subject 306, and image capture device 304F can capture a back view of subject 306.

[0045] The six light sources (i.e., light sources 302A, 302B, 302C, 302D, 302E, and 302F) and six image capture devices (i.e., image capture devices 304A, 304B, 304C, 304D, 304E, and 304F) shown in FIG. 3 are presented by way of example only. Environment 300 may include only one or more than six light sources and only one or more than six image capture devices without departing from the scope of this disclosure. For simplicity, only six light sources and six image capture devices are shown in FIG. 3 .

[0046] According to one embodiment, the circuitry 202 of the electronic device 102 can control each of the series of light sources 302A...302F to trigger a first series of flash pulses. The first series of flash pulses can include a first pulse and a second pulse. The object 306 can be initially illuminated with the first pulse and then illuminated with the second pulse. The illumination intensity of the first series of flash pulses can increase from a first intensity associated with the first pulse to a second intensity associated with the second pulse. The second intensity can be higher than the first intensity. Illuminating the object 306 with the (lower intensity) first pulse can facilitate the object 306 adapting to the (higher intensity) second pulse.

[0047] According to one embodiment, each of the series of light sources 302A...302F can include a linear polarizer. The linear polarizer can convert unpolarized light emitted by each of the series of light sources 302A...302F into horizontally polarized or vertically polarized light. The series of light sources 302A...302F can further include a circular polarizer (which can include a linear polarizer and a quarter-wave plate). The circular polarizer can convert horizontally polarized light into a parallel polarized illumination pattern. Similarly, the circular polarizer can convert vertically polarized light into a cross-polarized illumination pattern.

[0048] In some embodiments, the circuit 202 can be configured to control the series of image capture devices 304A...304F to capture an image of the object 306 based on illuminating the object 306 with horizontally or vertically polarized light. Each image capture device in the series of image capture devices 304A...304F can include a circular polarizer. The circular polarizer can be coupled to a lens of the image capture device (e.g., image capture device 304A). The circular polarizer can convert the horizontally polarized reflected light or the vertically polarized reflected light into a parallel polarized illumination pattern or a cross polarized illumination pattern, respectively. This conversion can be based on capturing the image of the object 306.

[0049] The circuitry 202 of the electronic device 102 may be further configured to select a sequence of illumination patterns for capturing an image of the object 306. The sequence of illumination patterns may be selected from a first sequence of illumination patterns and a second sequence of illumination patterns. According to some embodiments, the first sequence of illumination patterns may include at least one of a cross-polarized omnidirectional illumination pattern or a parallel-polarized omnidirectional illumination pattern. According to some embodiments, the second sequence of illumination patterns may include a first subset of cross-polarized spherical gradient illumination patterns and a second subset of parallel-polarized spherical gradient illumination patterns. The first subset of cross-polarized spherical gradient illumination patterns includes cross-polarized spherical gradient illumination patterns that can illuminate the object 306 from at least one of a left side of the object 306, a right side of the object 306, an upper side of the object 306, a lower side of the object 306, a front side of the object 306, and a rear side of the object 306. Similarly, the second subset of parallel polarized spherical gradient illumination patterns includes parallel polarized spherical gradient illumination patterns that can illuminate the subject 306 from at least one of the left side of the subject 306, the right side of the subject 306, the top side of the subject 306, the bottom side of the subject 306, the front side of the subject 306, and the back side of the subject 306.

[0050] According to one embodiment, the selection of the sequence of illumination patterns can be based on control of a circular polarizer included in each of the sequence of light sources 302A...302F. The circuitry 202 can control the circular polarizers to enable the sequence of light sources 302A...302F to illuminate the object 306 with a particular illumination pattern from the first sequence of illumination patterns and the second sequence of illumination patterns.

[0051] In some embodiments, the selection of the sequence of illumination patterns may be based on control of a circular polarizer coupled to the lens of each image capture device in the sequence of image capture devices 304A...304F. The circular polarizer may enable selection of a particular illumination pattern from the first sequence of illumination patterns and the second sequence of illumination patterns based on the capture of an image of the object 306.

[0052] The circuit 202 may further be configured to control each of the series of light sources 302A...302F to trigger a second series of flash pulses based on the illumination of the object 306 with the first series of flash pulses. In at least one embodiment, the second series of flash pulses may be triggered after the illumination of the object 114 with the first series of flash pulses. The second series of flash pulses may correspond to a selected series of illumination patterns. For example, each light source of the series of light sources 302A...302F may trigger a first flash pulse of the second series of flash pulses at a first time point. The illumination intensity of the first flash pulse triggered by each light source of the series of light sources 302A...302F may correspond to a second intensity. Thus, six first flash pulses (triggered by light sources 302A, 302B, 302C, 302D, 302E, and 302F) may be triggered simultaneously at a first time point. The six first flash pulses may correspond to a cross-polarized omnidirectional illumination pattern. Circuit 202 may be further configured to control each image capture device in the series of image capture devices 304A...304F to capture an image of object 306. Thus, at a first time point, six images may be captured based on illumination of object 306 with a cross-polarized omnidirectional illumination pattern (via six first flash pulses).

[0053] Similarly, the series of light sources 302A...302F can trigger six second flash pulses at a second time point having illumination intensities corresponding to the second intensities. The six second flash pulses can correspond to a parallel polarized omnidirectional illumination pattern. The series of image capture devices 304A...304F can simultaneously capture six images based on illuminating the object 306 with the parallel polarized omnidirectional illumination pattern (via the six second flash pulses) at a second time point.

[0054] According to an embodiment, the circuitry 202 can be configured to select all illumination patterns from a first subset of cross-polarized spherical gradient illumination patterns and select three illumination patterns from a second subset of parallel-polarized spherical gradient illumination patterns. The selected illumination patterns can include cross-polarized spherical gradient illumination patterns that can illuminate the object 306 from the left, right, above, below, front, and back. The selected illumination patterns can further include parallel-polarized spherical gradient illumination patterns that can illuminate the object 306 from the left, above, and front.

[0055] The set of light sources 302A...302F can simultaneously trigger six third flash pulses at a third time point based on a selection of an illumination pattern from the first subset of cross-polarized spherical gradient illumination patterns. The third flash pulses can correspond to cross-polarized spherical gradient illumination patterns that can illuminate the object 306 from the left side. In at least one embodiment, the illumination intensity of the third flash pulse triggered by light source 302A can be higher than the illumination intensity of the third flash pulse triggered by light source 302B. The set of image capture devices 304A...304F can capture six images at a third time point based on illuminating the object 306 from the left side with the cross-polarized spherical gradient illumination pattern (via the six third flash pulses).

[0056] Similarly, the set of image capture devices 304A...304F may capture six images at fourth, fifth, sixth, seventh, and eighth time points, respectively. The six images captured at fourth, fifth, sixth, seventh, and eighth time points may be based on illumination of object 306 from the right (by light source 302B), the top (by light source 302C), the bottom (by light source 302D), the front (by light source 302E), and the back (by light source 302F), respectively. The six images captured at fourth, fifth, sixth, seventh, and eighth time points may be based on illumination of object 306 with a cross-polarized spherical gradient illumination pattern (via six fourth flash pulses, six fifth flash pulses, six sixth flash pulses, six seventh flash pulses, and six eighth flash pulses, respectively).

[0057] Note that the illumination intensity of the fourth flash pulse triggered by light source 302B can be higher than the illumination intensity of the fourth flash pulse triggered by light source 302A. Similarly, the illumination intensity of the fifth flash pulse triggered by light source 302C (at a fifth time point) can be higher than the illumination intensity of the fifth flash pulse triggered by light source 302D, and the illumination intensity of the sixth flash pulse triggered by light source 302D (at a sixth time point) can be higher than the illumination intensity of the sixth flash pulse triggered by light source 302C. Furthermore, the illumination intensity of the seventh flash pulse triggered by light source 302E (at a seventh time point) can be higher than the illumination intensity of the seventh flash pulse triggered by light source 302F, and the illumination intensity of the eighth flash pulse triggered by light source 302F (at an eighth time point) can be higher than the illumination intensity of the eighth flash pulse triggered by light source 302E.

[0058] The series of image capture devices 304A...304F may simultaneously capture six images at ninth, tenth, and eleventh time points based on a selection of an illumination pattern from the second subset of parallel-polarized spherical gradient illumination patterns. The six images captured at the ninth, tenth, and eleventh time points may be based on illumination of the object 306 from the left (by light source 302A), the top (by light source 302C), and the front (by light source 302E), respectively. The six images captured at the ninth, tenth, and eleventh time points may be based on illumination of the object 306 with the parallel-polarized spherical gradient illumination pattern (via six ninth, six tenth, and six eleventh flash pulses, respectively).

[0059] Note that the illumination intensity of the ninth flash pulse triggered by light source 302A (at a ninth time point) can be higher than the illumination intensity of the ninth flash pulse triggered by light source 302B. Similarly, the illumination intensity of the tenth flash pulse triggered by light source 302C (at a tenth time point) can be higher than the illumination intensity of the tenth flash pulse triggered by light source 302D. Furthermore, the illumination intensity of the eleventh flash pulse triggered by light source 302E (at an eleventh time point) can be higher than the illumination intensity of the eleventh flash pulse triggered by light source 302F.

[0060] Thus, the series of image capture devices 304A...304F can capture 11 sets of images (each set including six images) based on illuminating the subject 306 with the second series of flash pulses (i.e., six first flash pulses, ..., six eleventh flash pulses). The second series of flash pulses can correspond to 11 selected illumination patterns (i.e., a cross-polarized omnidirectional illumination pattern, a parallel-polarized omnidirectional illumination pattern, six cross-polarized spherical gradient illumination patterns, and three parallel-polarized spherical gradient illumination patterns). Thus, the second series of flash pulses can include 66 flash pulses, and the series of image capture devices 304A...304F can capture 66 images of the subject 306. Note that the subject 306 can exhibit one facial expression during the capture of the 66 images.

[0061] It should be noted that the environment 300 of FIG. 3 is for illustrative purposes and should not be construed as limiting the scope of the present disclosure.

[0062] FIG. 4 illustrates an exemplary execution pipeline for controlling a lighting system for image capture using a series of multi-perspective image capture devices, according to an embodiment of the present disclosure. The description of FIG. 4 is provided with reference to elements in FIGS. 1, 2, and 3. FIG. 4 illustrates an exemplary pipeline 400. The exemplary pipeline 400 may include a series of operations (e.g., operations 402-408) that may be performed by one or more components of FIG. 1, such as the electronic device 102. The electronic device 102 may execute these operations to control the lighting system 104 to trigger flash pulses corresponding to a series of lighting patterns and to control the series of multi-perspective image capture devices 106 to capture images of the subject 114 illuminated by the flash pulses.

[0063] At 402, a sequence of illumination patterns 402B can be selected from a plurality of predefined illumination patterns 402A. The circuit 202 can be configured to select a sequence of illumination patterns 402B from the plurality of predefined illumination patterns 402A for capturing an image of the subject 114. According to an embodiment, the plurality of predefined illumination patterns 402A can include one or more of an omnidirectional illumination pattern, a directional illumination pattern, a cross-polarized illumination pattern, and a parallel-polarized illumination pattern. The selected sequence of illumination patterns 402B can include a first sequence of illumination patterns and a second sequence of illumination patterns. The first sequence of illumination patterns can include a cross-polarized omnidirectional illumination pattern and a parallel-polarized omnidirectional illumination pattern. The first sequence of illumination patterns can be used for shape (e.g., 3D face geometry or mesh) reconstruction and separation of diffuse and specular reflectance components (associated with the face surface).

[0064] The second set of illumination patterns can include a first subset of cross-polarized spherical gradient illumination patterns and a second subset of parallel-polarized spherical gradient illumination patterns. The first subset of cross-polarized spherical gradient illumination patterns can include cross-polarized spherical gradient illumination patterns that can illuminate the object 114 from the left, right, above, below, front, and back of the object 114. Similarly, the second subset of parallel-polarized spherical gradient illumination patterns can include parallel-polarized spherical gradient illumination patterns that can illuminate the object 114 from the left, right, above, below, front, and back of the object 114. The second set of illumination patterns can be used to generate a normal map and a height map.

[0065] According to an embodiment, the circuit 202 can be configured to select a first set of illumination patterns, one or more illumination patterns from a first subset of cross-polarized spherical gradient illumination patterns, and one or more illumination patterns from a second subset of parallel-polarized spherical gradient illumination patterns. The second set of illumination patterns can be used to generate a normal map and a height map. The quality of the generated normal map and height map can depend on the number of illumination patterns in the selected set of illumination patterns 402B. For example, the circuit 202 can select the first set of illumination patterns (i.e., two illumination patterns), all illumination patterns from the first subset of cross-polarized spherical gradient illumination patterns (i.e., six illumination patterns), and three illumination patterns from the second subset of parallel-polarized spherical gradient illumination patterns. The illumination patterns selected from the second subset can include parallel-polarized spherical gradient illumination patterns that can illuminate the subject 114 from the left, top, and front sides of the subject 114.

[0066] The circuit 202 can select all illumination patterns from the first subset of cross-polarized spherical gradient illumination patterns because the diffuse reflectance component in an image of the object 114 captured when the object 114 is illuminated with a cross-polarized gradient illumination pattern may not contain high-frequency details. Furthermore, in such cases, the quality of the image may not be affected by the movement of the object 114 during image capture. Using all illumination patterns from the first subset of cross-polarized spherical gradient illumination patterns can maximize the reconstruction quality of the captured image. The circuit 202 can select three illumination patterns from the second subset of parallel-polarized spherical gradient illumination patterns because the image of the object 114 captured when the object 114 is illuminated with a parallel-polarized spherical gradient illumination pattern may contain high-frequency details. The circuit 202 can select at least three illumination patterns from the second subset of parallel-polarized spherical gradient illumination patterns to avoid motion-related blur in the extracted specular reflectance component (including high-frequency details).

[0067] At 404, illumination of the subject 114 with a first series of flash pulses 404A can be controlled. The subject 114 can be illuminated based on the control of the lighting system 104. The circuit 202 can be configured to control the lighting system 104 associated with the electronic device 102 to illuminate the subject 114 with the first series of flash pulses 404A. The first series of flash pulses 404A can include a first pulse and a second pulse. The illumination intensity of the first series of flash pulses 404A can increase from a first intensity associated with the first pulse to a second intensity associated with the second pulse. Thus, the first intensity can be lower than the second intensity. For example, the increase in illumination intensity from the first intensity to the second intensity can be a linear increase. The linear increase in illumination intensity can allow the subject 114 to adapt to the second pulse at a second intensity (i.e., a higher light intensity). According to an embodiment, the first pulse can correspond to modeling light, and the first intensity can correspond to a predetermined intensity.

[0068] At 406, illumination of the object 114 with a second series of flash pulses 406A can be controlled. The object 114 can be illuminated based on the control of the illumination system 104. The circuit 202 can be configured to control the illumination system 104 to illuminate the object 114 with the second series of flash pulses 406A. According to an embodiment, the second series of flash pulses 406A can correspond to a selected series of illumination patterns 402B. Thus, the second series of flash pulses 406A can correspond to the first series of illumination patterns, a first subset of the cross-polarized spherical gradient illumination patterns, and the selected one or more parallel polarized illumination patterns.

[0069] In some embodiments, the second series of flash pulses 406A can correspond to linearly polarized illumination (i.e., horizontally polarized illumination or vertically polarized illumination). The circuitry 202 can be configured to control the series of multi-view image capture devices 106 to convert the linearly polarized illumination into a first series of illumination patterns (i.e., cross-polarized or parallel-polarized omnidirectional illumination patterns) or a second series of illumination patterns (i.e., cross-polarized or parallel-polarized spherical gradient illumination patterns) based on the capture of images of the object 114. For example, the second series of flash pulses 406A corresponding to horizontally polarized illumination can be converted into a parallel-polarized omnidirectional illumination pattern or a parallel-polarized spherical gradient illumination pattern. Similarly, the second series of flash pulses 406A corresponding to vertically polarized illumination can be converted into a cross-polarized omnidirectional illumination pattern or a cross-polarized spherical gradient illumination pattern.

[0070] According to an embodiment, the illumination intensity of the second series of flash pulses 406A corresponding to the first series of illumination patterns (i.e., a cross-polarized or parallel-polarized omnidirectional illumination pattern) can be equal to the second intensity. The illumination intensity of the second series of flash pulses 406A corresponding to the second series of illumination patterns can vary based on the selected illumination pattern of the second series of illumination patterns. For example, the illumination intensity of a first flash pulse of the second series of flash pulses 406A triggered by the light source 104A can be higher than the illumination intensity of a second flash pulse of the second series of flash pulses 406A triggered by the light source 104B. In a first scenario, if the light source 104A is positioned to the left of the object 114 and the light source 104B is positioned to the right of the object 114, the first flash pulse and the second flash pulse can correspond to a cross-polarized or parallel-polarized spherical gradient illumination pattern that illuminates the object 114 from the left side. In a second scenario, if light source 104A is located on the right side and light source 104B is located on the left side, the first and second flash pulses can correspond to a cross-polarized or parallel-polarized spherical gradient illumination pattern that illuminates object 114 from the right side. Similarly, in other scenarios, the first and second flash pulses correspond to a cross-polarized or parallel-polarized spherical gradient illumination pattern that illuminates object 114 from above, below, front, or back of object 114.

[0071] At 408, the capture of each of the series of images of the object 114 may be controlled. Each of the series of images may be captured via control of the series of multi-perspective image capture devices 106. The circuit 202 may be configured to control the series of multi-perspective image capture devices 106 associated with the electronic device 102 to capture each of the series of images of the object 114 based on illuminating the object 114 with a second series of flash pulses 406A. The second series of flash pulses 406A may correspond to the (selected) series of illumination patterns 402B. Accordingly, the circuit 202 may control the series of multi-perspective image capture devices 106 to capture each of the series of images of the object 114 based on illuminating the object 114 with each illumination pattern of the selected series of illumination patterns 402B via the second series of flash pulses 406A. For example, the selected series of illumination patterns 402B may include 11 illumination patterns: a cross-polarized omnidirectional illumination pattern, a parallel-polarized omnidirectional illumination pattern, six cross-polarized spherical gradient illumination patterns, and three parallel-polarized spherical gradient illumination patterns. The circuitry 202 may control the series of multi-perspective image capture devices 106 to capture 11 sets of images of the object 114. Each set of the 11 images may be captured based on illumination of the object 114 with one of the 11 illumination patterns. Furthermore, each set of the 11 images may include six images, one from each capture direction (e.g., left side, right side, top side, bottom side, front side, and back side) relative to the object 114.

[0072] According to some embodiments, the number of images in each set of 11 images may be based on a capture mode associated with the series of multi-view image capture devices 106 and the number of image capture devices in the series of multi-view image capture devices 106. The capture mode may correspond to a single-shot mode or a burst mode. In single-shot mode, each image capture device in the series of multi-view image capture devices 106 may capture a single image during the time interval between the opening and closing of the shutter of the image capture device (or the time interval during which the shutter of the image capture device may be open). The circuitry 202 may be further configured to synchronize the opening and closing of the shutters of all image capture devices in the series of multi-view image capture devices 106. The circuitry 202 may control each image capture device in the series of multi-view image capture devices 106 to set a time interval. The time interval may correspond to a shutter speed associated with each image capture device in the series of multi-view image capture devices 106.

[0073] According to one embodiment, the circuit 202 can set a shutter speed associated with each image capture device in the series of multi-perspective image capture devices 106 based on the capture mode (i.e., single-shot mode or burst mode) associated with the capture of each image in the series. For example, in single-shot mode, the shutter speed associated with each image capture device in the series of multi-perspective image capture devices 106 can be set as 1 / 60 seconds. The circuit 202 can control a light source (e.g., light source 104A) in the illumination system 104 to trigger a flash pulse corresponding to a cross-polarized omnidirectional illumination pattern in the second series of flash pulses 406A. The flash pulse can be triggered during the time interval for capturing an image (i.e., 1 / 60 seconds). According to one embodiment, the circuit 202 can set a delay and flash duration associated with the illumination system 104 (i.e., light sources 104A...104N) based on the shutter speed (associated with each image capture device in the series of multi-perspective image capture devices 106). For example, if the flash duration is set as 1 / 1000 seconds, the delay can be set as 1 / 120 seconds. The delay can ensure that light source 104A triggers a flash pulse at the center (eg, 1 / 30th of a second) of the time interval (ie, 1 / 60th of a second time interval).

[0074] According to one embodiment, the circuit 202 can be configured to synchronize the illumination system 104 and the series of multi-perspective image capture devices 106 to capture each of a series of images of the object 114 based on a delay and a flash duration. For example, the circuit 202 can synchronize the light source 104A of the illumination system 104 with the image capture device 106A of the series of multi-perspective image capture devices 106. The circuit 202 can control the image capture device 106A to capture an image of the object 114 illuminated with a flash pulse (of the second series of flash pulses 406A) corresponding to a cross-polarized omnidirectional illumination pattern. The flash pulse can be triggered at the center of the time interval between the opening and closing of a shutter associated with the image capture device 106A.

[0075] Similarly, each of the other image capture devices in the series of multi-perspective image capture devices 106 can capture an image of the object 114 based on illuminating the object 114 with flash pulses (of the second series of flash pulses 406A) corresponding to the cross-polarized omnidirectional illumination pattern. The capture of the image of the object 114 can be based on synchronization between the light sources 104B...104N and the image capture devices 106B...106N of the illumination system 104. Each of the light sources 104B...104N can trigger a flash pulse of the second series of flash pulses 406A at the center of the time interval between the opening and closing of a shutter associated with each of the image capture devices 106B...106N. Thus, the series of multi-perspective image capture devices 106 can capture "N" images of the object 114 in single-shot mode based on illuminating the object 114 with the second series of flash pulses 406A corresponding to the cross-polarized omnidirectional illumination pattern.

[0076] Similarly, circuitry 202 can be configured to control the series of multi-perspective image capture devices 106 to capture "N" images of object 114 in single-shot mode for each of the remaining ten illumination patterns in selected series of illumination patterns 402B. The series of multi-perspective image capture devices 106 can capture a total of "11*N" images of object 114 in single-shot mode.

[0077] In burst mode, each image capture device in the array of multi-perspective image capture devices 106 can capture multiple images over multiple time intervals during which the shutter of the image capture device is open. The multiple images can be captured based on the triggering of multiple flash pulses in the second series of flash pulses 406A corresponding to one lighting pattern in the selected series of lighting patterns 402B. The circuit 202 can set a shutter speed (corresponding to the time interval) associated with each image device in the array of multi-perspective image capture devices 106. For example, the shutter speed can be set as 1 / 125 seconds.

[0078] This setting may be optimal because shutter speeds faster than 1 / 125 seconds can affect the brightness of the captured image. Furthermore, shutter speeds slower than 1 / 125 seconds can prevent the image capture devices in the chain of multi-perspective image capture devices 106 from operating efficiently in burst mode. For example, shutter speeds slower than 1 / 125 seconds (i.e., the time interval during which the shutter is open is longer than 1 / 125 seconds) can affect synchronization between the image capture devices in the chain of multi-perspective image capture devices 106. This is because the duration of in-camera (i.e., in the image capture device) image processing can be directly proportional to the time interval. An increased duration of in-camera image processing (due to a longer time interval (faster than 1 / 125 seconds)) can result in synchronization loss between the image capture devices in the chain of multi-perspective image capture devices 106. On the other hand, if the shutter speed is faster than 1 / 125 second (i.e., the shutter is open for a shorter time interval than 1 / 125 second), synchronization between the light source (e.g., light source 104A) of illumination system 104 and the image capture devices (e.g., image capture device 106A) of array of multi-perspective image capture devices 106 may be affected, causing one or more image capture devices in array of multi-perspective image capture devices 106 to miss a flash pulse for capturing a sequence of images in second sequence of flash pulses 406A.

[0079] The circuit 202 can control a light source (e.g., light source 104A) of the illumination system 104 to trigger multiple flash pulses (e.g., bursts) corresponding to the cross-polarized omnidirectional illumination pattern of the second series of flash pulses 406A at multiple time intervals. The shutter of each image capture device of the series of multi-viewpoint image capture devices 106 can be open during each time interval of the multiple time intervals. Each flash pulse of the multiple flash pulses can be triggered during each time interval (i.e., 1 / 125 seconds) to capture an image. For example, the light source 104A can trigger three flash pulses corresponding to the cross-polarized omnidirectional illumination pattern to capture three images during three time intervals. The flash duration can be set to, for example, 1 / 1000 seconds. The delay can be set so that each of the three flash pulses is triggered at the center (i.e., 1 / 250 seconds) of each corresponding time interval (i.e., 1 / 125 seconds).

[0080] The circuit 202 can control the image capture device 106A to capture three images of the object 114 illuminated with three flash pulses (of the second series of flash pulses 406A) corresponding to the cross-polarized omnidirectional illumination pattern. The three flash pulses can be triggered within three time intervals during which a shutter associated with the image capture device 106A is in an open state. Similarly, each other image capture device in the series of multi-perspective image capture devices 106 can capture three images of the object 114 based on the illumination of the object 114 with the three flash pulses (of the second series of flash pulses 406A) corresponding to the cross-polarized omnidirectional illumination pattern. Thus, the series of multi-perspective image capture devices 106 can capture “3*N” images of the object 114 in burst mode based on the illumination of the object 114 with the second series of flash pulses 406A corresponding to the cross-polarized omnidirectional illumination pattern.

[0081] Similarly, the circuitry 202 may be configured to control the series of multi-perspective image capture devices 106 to capture 3*N images of the subject 114 in burst mode for each of the remaining ten lighting patterns in the selected series of lighting patterns 402B. The series of multi-perspective image capture devices 106 may capture a total of 33*N images of the subject 114 in burst mode. Note that the 11*N images of the subject 114 (captured in single-shot mode) or the 33*N images (captured in burst mode) may be captured based on a particular facial expression of the subject 114. The facial expression may result in movement of facial features or expression of emotion.

[0082] According to one embodiment, circuitry 202 can be configured to control an autofocus setting associated with each image capture device in the series of multi-perspective image capture devices 106. Circuitry 202 can control the series of multi-perspective image capture devices 106 to capture each of the series of images of subject 114 based on the control of the autofocus setting. For example, the autofocus setting of each image capture device in the series of multi-perspective image capture devices 106 can be controlled prior to capturing each of the series of images of subject 114. The autofocus setting of each of the image capture devices can be enabled based on coupling a circular polarizer to the lens of each image capture device (e.g., an 85 millimeter lens with an F1.8 aperture).

[0083] According to an embodiment, the auto-focus setting can correspond to per-capture auto-focus, per-session auto-focus, or per-frame auto-focus.

[0084] If the autofocus setting supports capture-by-capture autofocus, the circuit 202 can control the autofocus setting (associated with each image capture device in the series of multi-perspective image capture devices 106) before each capture of a series of images of the subject 114 exhibiting a particular facial expression. For example, a first control of the autofocus setting can be performed before capturing 11*N or 33*N images of the subject 114 exhibiting a first facial expression. Once the 11*N or 33*N images have been captured, a second control of the autofocus setting can be performed. A second control of the autofocus setting can be performed to capture another 11*N or 33*N images of the subject 114 exhibiting a second facial expression. Thus, the autofocus setting of each image capture device is maintained for each capture of a series of images based on the illumination of the subject 114 in each of the eleven selected lighting patterns. With per-capture autofocus, the circuit 202 can accommodate potential head movements (i.e., head movements of the subject 114) during the capture of 11*N or 33*N images of the subject 114 exhibiting a particular facial expression. The circuit 202 can be further configured to perform post-rigid alignment to compensate for changes in one or more intrinsic parameters (e.g., focal length of one image capture device in the series of multi-perspective image capture devices 106, distortion associated with the lens of the image capture device, or position of the sensor of the image capture device). The one or more intrinsic parameters can be changed each time the autofocus settings are controlled before each capture of a series of images of the subject 114 exhibiting a particular facial expression.

[0085] If the autofocus settings correspond to per-session autofocus, the circuit 202 may control the autofocus settings (associated with each image capture device in the series of multi-perspective image capture devices 106) once before each capture of a series of images of the subject 114 exhibiting a series of facial expressions. For example, the autofocus settings controlled before the capture of 11*N or 33*N images of the subject 114 exhibiting a first facial expression may be retained for the capture of the corresponding 11*N or 33*N images of the subject 114 exhibiting a second facial expression.

[0086] If the autofocus setting corresponds to frame-by-frame autofocus, the circuit 202 may control the autofocus setting (associated with each image capture device in the series of multi-view image capture devices 106) each time before capturing a series of images of the subject 114 illuminated with one of the selected series of illumination patterns 402B. For example, a first control of the autofocus setting may occur before capturing “N” or “3*N” images of the subject 114 that may exhibit a facial expression illuminated with a first illumination pattern of the 11 selected illumination patterns. Once the “N” or “3*N” images have been captured, a second control of the autofocus setting may occur. For example, a second control of the autofocus setting may occur to capture another “N” or “3*N” images of the subject 114 that may exhibit the same facial expression illuminated with a second illumination pattern of the 11 selected illumination patterns.

[0087] According to one embodiment, the circuit 202 can be configured to receive a first indication that a first series of images has been captured by the series of multi-perspective image capture devices 106 based on illuminating the subject 114 with a first lighting pattern from the selected series of lighting patterns 402B. The first indication can be received based on input from a user associated with the series of multi-perspective image capture devices 106. Additionally or alternatively, the first indication can be received automatically from at least one of the series of multi-perspective image capture devices 106 or the lighting system 104. The circuit 202 can be further configured to control the lighting system 104 to illuminate the subject 114 with a first pulse associated with a first intensity from the first series of flash pulses 404A based on the received first indication. The subject 114 can be illuminated with a flash pulse corresponding to the first lighting pattern from the second flash pulses 406A prior to receiving the first indication. The flash pulse can be associated with a second intensity that is higher than the first intensity. Once the first series of images has been captured, the circuitry 202 may trigger a first pulse (of a lower intensity relative to the intensity of the flash pulse) through each of the light sources 104A...104N in response to the received first instruction and controlling the illumination system 104. Triggering the first pulse may ensure that the subject 114 is not exposed to higher intensity light when the series of multi-perspective image capture devices 106 are not engaged in image capture.

[0088] According to one embodiment, the circuit 202 can be configured to receive a second indication that a second series of images has been captured using the series of multi-perspective image capture devices 106. The second indication can be received based on input from a user associated with the series of multi-perspective image capture devices 106. Additionally or alternatively, the second indication can be received automatically from at least one of the series of multi-perspective image capture devices 106 or the lighting system 104. Based on the received second indication, the circuit 202 can be configured to control the lighting system 104 to illuminate the subject 114 with a first series of flash pulses 404A. The first series of flash pulses 404A can begin with a first pulse of lower intensity and end with a second pulse of higher intensity than the first pulse. The circuit 202 can further be configured to control the lighting system 104 to illuminate the subject 114 with a second series of flash pulses 406A based on the illumination of the subject 114 with the first series of flash pulses 404A (which can lead to the second pulse). The second series of flash pulses 406A may be triggered after illuminating the subject 114 with the second pulse (i.e., after the subject 114 has acclimatized to the second pulse and the second intensity associated with the second series of flash pulses 406A). The second series of flash pulses 406A may correspond to a second illumination pattern in the selected series of illumination patterns 402B. The circuitry 202 may be further configured to control the series of multi-perspective image capture devices 106 to capture a second image in the series of images based on the illumination of the subject 114 with the second series of flash pulses 406A.

[0089] FIG. 5A is a first exemplary timing diagram illustrating synchronization between an illumination system and a series of multi-perspective image capture devices for image capture in single-shot mode, according to an embodiment of the present disclosure. The description of FIG. 5A is provided with reference to elements in FIGS. 1, 2, 3, and 4. FIG. 5A illustrates an exemplary timing diagram 500A. The exemplary timing diagram 500A illustrates a timeline indicating when a shutter associated with each image capture device (in the series of multi-perspective image capture devices 106) can be opened and closed. The timeline further illustrates when each light source of the illumination system 104 can trigger a flash pulse based on when the shutter can be opened and closed. The circuit 202 can synchronize the triggering of the flash pulse with the opening and closing of the shutter to capture an image of the subject 114.

[0090] According to one embodiment, the capture mode associated with the series of multi-perspective image capture devices 106 can be a single-shot mode. In single-shot mode, each image capture device in the series of multi-perspective image capture devices 106 can capture a single image during the time interval between the opening and closing of the image capture device's shutter. For example, during a first time interval 502, one image capture device (e.g., image capture device 106A) in the series of multi-perspective image capture devices 106 can capture an image of the subject 114. During the first time interval 502, the shutter associated with image capture device 106A can be open to enable the capture. The first time interval 502 can correspond to the shutter speed of the shutter associated with the image capture device 106. The circuit 202 can set the shutter speed as 1 / 60 seconds.

[0091] The circuitry 202 can be configured to synchronize the lighting system 104 with the series of multi-perspective image capture devices 106. This synchronization allows each light source of the lighting system 104 to trigger a flash pulse based on the opening of a shutter associated with an image capture device in the series of multi-perspective image capture devices 106. For example, the light source 104A can trigger a flash pulse during the first time interval 502. The flash pulse can correspond to a first lighting pattern in the selected series of predefined lighting patterns 402A. The image capture device 106A can capture an image of the object 114 (during the first time interval 502) based on the illumination of the object 114 (with the first lighting pattern in the selected series of predefined lighting patterns 402A) via the flash pulse triggered by the light source 104A.

[0092] According to an embodiment, the circuit 202 can be configured to set a delay and flash duration associated with the illumination system 104 based on a shutter speed. For example, the circuit 202 can set a delay 502A and configure the flash duration as 1 millisecond (or 1 / 1000 seconds). The delay 502A can be set based on the shutter speed (or first time interval 502). The circuit 202 can control the light source 104A to trigger a 1 millisecond flash pulse with delay 502A relative to the opening of a shutter associated with the image capture device 106A. The captured image can be processed within the time interval 504. The first time interval 502 and the time interval 504 can span 0.5 seconds.

[0093] According to an embodiment, the circuitry 202 may be further configured to control the image capture device 106A to capture an image of the object 114 during a second time interval 506 based on illumination of the object 114 with a second illumination pattern in the selected sequence of illumination patterns 402B. The image captured during the second time interval 506 may be processed in a time interval 508. The circuitry 202 may be further configured to control the image capture device 106A to capture an image of the object 114 during a third time interval 510 based on illumination of the object 114 with a third illumination pattern in the selected sequence of illumination patterns.

[0094]

[0033] Figure 5B is a second exemplary timing diagram illustrating synchronization between an illumination system and a series of multi-perspective image capture devices for image capture in burst mode, according to an embodiment of the present disclosure. Figure 5B is described with reference to elements of Figures 1, 2, 3, 4, and 5A. Figure 5B illustrates an exemplary timing diagram 500B. The exemplary timing diagram 500B illustrates a timeline indicating when a shutter associated with each image capture device (in the series of multi-perspective image capture devices 106) can open and close. The timeline further illustrates when each light source of the illumination system 104 can trigger a flash pulse based on the opening and closing of the shutter in burst mode.

[0095] According to one embodiment, each image capture device in the series of multi-perspective image capture devices 106 can capture multiple images in burst mode during multiple time intervals spanning the opening and closing of the image capture device's shutter. For example, image capture device 106A can capture three images when the shutter associated with image capture device 106A is open (i.e., a first image during time interval 512, a second image during time interval 516, and a third image during time interval 520). Time intervals 512, 516, and 520 can correspond to a shutter speed that can be set as 1 / 125 seconds. Synchronizing illumination system 104 and the series of multi-perspective image capture devices 106 allows light source 104A to trigger three flash pulses that can correspond to a first lighting pattern in the selected series of lighting patterns 402B. During time interval 512, a first flash pulse 528A can be triggered to capture a first image, during time interval 516, a second flash pulse 528B can be triggered to capture a second image, and during time interval 520, a third flash pulse 528C can be triggered to capture a third image.

[0096] Image capture device 106A can capture three images of object 114 based on illumination of object 114 (in a first illumination pattern) via three flash pulses (i.e., first flash pulse 528A, second flash pulse 528B, and third flash pulse 528C) triggered by light source 104A. First flash pulse 528A, second flash pulse 528B, and third flash pulse 528C can be of the same duration (e.g., 1 millisecond). The first image can be processed within time interval 514. The second image can be processed within time interval 518. The third image can be processed within time interval 522. Time interval 512 (or time intervals 516 and 520) and time interval 514 (or time intervals 518 and 522) can span 0.1 seconds.

[0097] According to one embodiment, the circuit 202 can be configured to set flash durations associated with three flash pulses. For example, the flash duration of each of the three flash pulses can be set as 1 millisecond (1 / 1000 seconds). The circuit 202 can be configured to set a delay 512A for a first flash pulse 528A, a delay 516A for a second flash pulse 528B, and a delay 520A for a third flash pulse 528C. The delays 512A, 516A, and 520A can be of the same duration. The circuit 202 can control the light source 104A to trigger the first flash pulse 528A of 1 millisecond duration with a delay 512A relative to the opening of a shutter associated with the image capture device 106A. Similarly, the circuit 202 can control the light source 104A to trigger the second flash pulse 528B and the third flash pulse 528C with delays 516A and 520A relative to the opening of a shutter associated with the image capture device 106A, respectively.

[0098] According to one embodiment, the circuit 202 may be further configured to control the image capture device 106A to capture three images of the subject 114 based on the illumination of the subject 114 (with a second lighting pattern in the selected sequence of lighting patterns 402B) via three flash pulses. For example, the image capture device 106A may capture an image during a time interval 524 during which a shutter associated with the image capture device 106A may be open. During the time interval 524, a flash pulse 530A may be triggered to capture the image. The image capture device 106A may capture two additional images based on the illumination of the subject 114 (with the second lighting pattern) via two flash pulses. The two flash pulses may be triggered during successive time intervals after the time interval 524.

[0099] Similarly, circuitry 202 may be further configured to control image capture device 106A to capture three images of subject 114 based on the illumination of subject 114 with each of the other illumination patterns in selected sequence of illumination patterns 402B. Circuitry 202 may be further configured to control each image capture device in sequence of multi-perspective image capture devices 106 to capture three images of subject 114 based on the illumination of subject 114 with each of the illumination patterns in selected sequence of illumination patterns 402B.

[0100] It should be noted that the timing diagrams 500A and 500B of FIGS. 5A and 5B are for illustrative purposes and should not be construed as limiting the scope of the present disclosure.

[0101] Figure 6 is a flowchart illustrating operations of an exemplary method for controlling a lighting system for image capture using a multi-view image capture device, according to an embodiment of the present disclosure. Figure 6 is described with reference to elements in Figures 1, 2, 3, 4, and 5. Figure 6 shows a flowchart 600. Operations 602-610 can be performed by any computer system, such as, for example, electronic device 102 of Figure 1. Operations can begin at 602 and proceed to 604.

[0102] At 604, a sequence of illumination patterns can be selected from a plurality of predetermined illumination patterns for capturing a sequence of images of the object 114. In at least one embodiment, the circuit 202 can be configured to select a sequence of illumination patterns from a plurality of predetermined illumination patterns for capturing a sequence of images of the object 114. Details of selecting a sequence of illumination patterns from a plurality of predetermined illumination patterns are described, for example, in FIGS. 1, 3, and 4 (402).

[0103] At 606, the lighting system 104 associated with the electronic device 102 can be controlled to illuminate the subject 114 with a first series of flash pulses including a first pulse and a second pulse, where the illumination intensity of the first series of flash pulses can increase from a first intensity associated with the first pulse to a second intensity associated with the second pulse, where the first intensity can be lower than the second intensity. In at least one embodiment, the circuit 202 can be configured to control the lighting system 104 associated with the electronic device 102 to illuminate the subject 114 with the first series of flash pulses including the first pulse and the second pulse. The illumination intensity of the first series of flash pulses can increase from a first intensity associated with the first pulse to a second intensity associated with the second pulse, where the first intensity can be lower than the second intensity. Details of controlling the lighting system 104 to illuminate the subject 114 with the first series of flash pulses are described, for example, in FIGS. 1 , 3 , and 4 (step 404).

[0104] At 608, the illumination system 104 can be controlled to illuminate the subject 114 with a second series of flash pulses based on the illumination of the subject 114 with the first series of flash pulses, where the second series of flash pulses can correspond to a selected series of lighting patterns and where the illumination intensity of each of the flash pulses in the second series can correspond to a second intensity. In at least one embodiment, the circuit 202 can be configured to control the illumination system 104 to illuminate the subject 114 with a second series of flash pulses based on the illumination of the subject 114 with the first series of flash pulses. The second series of flash pulses can correspond to a selected series of lighting patterns and where the illumination intensity of each of the second series can correspond to a second intensity. Details of controlling the illumination system 104 to illuminate the subject 114 with the second series of flash pulses are described, for example, in FIGS. 1 , 3 and 4 (step 406).

[0105] At 610, the set of multi-perspective image capture devices 106 associated with the electronic device 102 can be controlled to capture each of the set of images of the object 114 based on illuminating the object 114 with the second set of flash pulses. In at least one embodiment, the circuit 202 can be configured to control the set of multi-perspective image capture devices 106 associated with the electronic device 102 to capture each of the set of images of the object 114 based on illuminating the object 114 with the second set of flash pulses. Details of controlling the set of multi-perspective image capture devices 106 to capture the set of images of the object 114 are described, for example, in Figures 1, 3, and 4 (step 408). Control can proceed to end.

[0106] Although flowchart 600 is depicted as discrete operations such as 604, 606, 608, and 610, the disclosure is not so limited. Thus, in some embodiments, such discrete operations may be further divided into additional operations, combined into fewer operations, or eliminated, depending on the implementation, without departing from the essence of the disclosed embodiments.

[0107] Various embodiments of the present disclosure may provide a non-transitory computer-readable medium and / or storage medium having stored thereon computer-executable instructions executable by a machine and / or a computer to operate an electronic device (such as the electronic device 102). The computer-executable instructions may cause the machine and / or computer to perform operations including selecting a sequence of illumination patterns from a plurality of predetermined illumination patterns for capturing a sequence of images of the object 114. The operations may further include controlling an illumination system 104 associated with the electronic device 102 to illuminate the object 114 with a first sequence of flash pulses including a first pulse and a second pulse. An illumination intensity of the first sequence of flash pulses may increase from a first intensity associated with the first pulse to a second intensity associated with the second pulse. The first intensity may be lower than the second intensity. The operations may further include controlling the illumination system 104 to illuminate the object 114 with a second sequence of flash pulses based on the illumination of the object 114 with the first sequence of flash pulses. The second sequence of flash pulses may correspond to the selected sequence of illumination pattern. The illumination intensity of each of the second series of flash pulses can correspond to the second intensity. The operations can further include controlling a series of multi-perspective image capture devices 106 associated with the electronic device 102 to capture each of the series of images of the subject 114 based on the illumination of the subject 114 with the second series of flash pulses.

[0108] An exemplary embodiment of the present disclosure may include an electronic device (such as the electronic device 102 of FIG. 1 ) that may include a circuit (such as the circuit 202) communicatively coupleable to the electronic device (such as the electronic device 102 of FIG. 1 ). The circuit 202 may be configured to select a sequence of illumination patterns from a plurality of predetermined illumination patterns for capturing a sequence of images of a subject (e.g., the subject 114). The plurality of predetermined illumination patterns may correspond to one or more of an omnidirectional illumination pattern, a directional illumination pattern, a cross-polarized illumination pattern, or a parallel-polarized illumination pattern. The selected sequence of illumination patterns may correspond to a first sequence of illumination patterns for shape reconstruction or a second sequence of illumination patterns for normal and height map generation. The first sequence of illumination patterns may include a cross-polarized omnidirectional illumination pattern or a parallel-polarized omnidirectional illumination pattern. The second set of illumination patterns may include a cross-polarized illumination pattern that illuminates the subject 114 from the left side of the subject 114, a parallel polarized illumination pattern that illuminates the subject from the left side, a cross-polarized illumination pattern that illuminates the subject 114 from the right side of the subject 114, a parallel polarized illumination pattern that illuminates the subject from the right side, a cross-polarized illumination pattern that illuminates the subject from above the subject 114, a parallel polarized illumination pattern that illuminates the subject 114 from above, a cross-polarized illumination pattern that illuminates the subject from below the subject 114, a parallel polarized illumination pattern that illuminates the subject from below, a cross-polarized illumination pattern that illuminates the subject 114 from in front of the subject 114, a parallel polarized illumination pattern that illuminates the subject 114 from the front, a cross-polarized illumination pattern that illuminates the subject 114 from behind the subject 114, or a parallel polarized illumination pattern that illuminates the subject 114 from behind.

[0109] The circuit 202 may be further configured to control the lighting system 104 associated with the electronic device 102 to illuminate the subject 114 with a first series of flash pulses, including a first pulse and a second pulse. The illumination intensity of the first series of flash pulses increases from a first intensity associated with the first pulse to a second intensity associated with the second pulse. The first intensity may be lower than the second intensity. The first pulse may correspond to modeling light, and the first intensity may correspond to a predetermined intensity. The circuit 202 may be further configured to control the lighting system 104 to illuminate the subject 114 with a second series of flash pulses based on the illumination of the subject 114 with the first series of flash pulses. The second series of flash pulses may correspond to a selected series of illumination patterns. The illumination intensity of each of the flash pulses in the second series may correspond to the second intensity. The circuitry 202 may be further configured to control a series of multi-perspective image capture devices associated with the electronic device 102 (e.g., the series of multi-perspective image capture devices 106) to capture each of a series of images of the subject 114 based on illuminating the subject 114 with the second series of flash pulses.

[0110] According to an embodiment, the circuitry 202 may be further configured to determine a shutter speed associated with each of the series of multi-perspective image capture devices 106 based on a capture mode associated with capturing the series of images. The circuitry 202 may be further configured to determine a delay and flash duration associated with the lighting system 104 based on the determined shutter speed. The circuitry 202 may be further configured to synchronize the lighting system 104 and the series of multi-perspective image capture devices 106 to capture the series of images of the subject 114 based on the determined delay and flash duration. The capture mode may be a single-shot mode or a burst mode.

[0111] According to an embodiment, the circuitry 202 may be further configured to control an autofocus setting associated with each of the series of multi-perspective image capture devices 106. The circuitry 202 may be further configured to control the series of multi-perspective image capture devices 106 to capture a series of images of the subject 114 further based on controlling the camera's autofocus setting. The autofocus setting may correspond to capture-by-capture autofocus, session-by-session autofocus, or frame-by-frame autofocus.

[0112] According to an embodiment, the circuitry 202 may be further configured to receive a first indication that a first image has been captured from the series of images by the series of multi-perspective image capture devices 106. The circuitry 202 may be further configured to: control the illumination system 104 to illuminate the subject 114 with a first pulse associated with a first intensity based on the received first indication.

[0113] According to an embodiment, the circuit 202 can be further configured to receive a second instruction indicating that the series of multi-perspective image capture devices 106 have initiated capture of a second image from the series of images. The circuit 202 can be further configured to control the illumination system 104 to illuminate the subject 114 with a first series of flash pulses based on the received second instruction. The circuit 202 can be further configured to control the illumination system 104 to illuminate the subject 114 with the first series of flash pulses and based on the received second instruction. The circuit 202 can be further configured to control the series of multi-perspective image capture devices 106 to capture a second image from the series of images based on the illumination of the subject 114 with the second series of flash pulses and based on the received second instruction.

[0114] The present disclosure can be implemented in hardware or a combination of hardware and software. The present disclosure can be implemented in a centralized manner in at least one computer system, or in a distributed manner where different elements can be distributed across several interconnected computer systems. Any computer system or other device adapted to perform the methods described herein can be suitable. The combination of hardware and software can be a general-purpose computer system that includes a computer program that, when loaded and executed, can control the computer system to perform the methods described herein. The present disclosure can be implemented in hardware, including portions of integrated circuits that also perform other functions.

[0115] The present disclosure may also be embodied in a computer program product, which includes all features that enable the implementation of the methods described herein and which is capable of executing these methods when loaded into a computer system. A computer program in this context means any expression, in any language, code or notation, of a set of instructions intended to cause a system having information processing capabilities to perform a particular function, either directly, or after a) conversion into another language, code or notation, or b) reproduction in a different content form, or both.

[0116] While the present disclosure has been described with reference to several embodiments, those skilled in the art will recognize that various modifications may be made and equivalents may be substituted without departing from the scope of the disclosure. Additionally, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from the scope of the disclosure. Therefore, it is not intended that the disclosure be limited to the particular embodiments disclosed, but rather, it is intended to include all embodiments falling within the scope of the appended claims. [Explanation of symbols]

[0117] 100 Network Environment 102 Electronic equipment 104 Lighting System 104A~N light source 106 A series of multi-viewpoint image capture devices 106A~N Image capture device 108 servers 110 databases 112 Communication Network 114 Subject

Claims

1. 1. An electronic device, comprising: selecting a sequence of illumination patterns from a plurality of predetermined illumination patterns for capturing images of the subject; controlling an illumination system associated with the electronic device to illuminate the subject with a first series of flash pulses including a first pulse and a second pulse, the illumination intensity increasing from a first intensity associated with the first pulse to a second intensity associated with the second pulse, the first intensity being less than the second intensity; controlling the illumination system based on the illumination of the object with the first series of flash pulses to illuminate the object with a second series of flash pulses corresponding to the selected series of illumination patterns, the second series of flash pulses having respective illumination intensities corresponding to the second intensity; controlling a series of multi-view image capture devices associated with the electronic device to capture each of a series of images of the subject based on illumination of the subject with the second flash pulse; a circuit configured to: An electronic device characterized by:

2. the plurality of predetermined illumination patterns correspond to one or more of an omnidirectional illumination pattern, a directional illumination pattern, a cross-polarized illumination pattern, or a parallel-polarized illumination pattern; The electronic device of claim 1 .

3. the selected set of illumination patterns corresponds to at least one of a first series of illumination patterns for shape reconstruction or a second series of illumination patterns for normal map and height map generation; The electronic device of claim 1 .

4. the first series of illumination patterns includes one or more of a cross-polarized omnidirectional illumination pattern or a parallel-polarized omnidirectional illumination pattern; The electronic device of claim 3 .

5. The second series of illumination patterns comprises: a cross-polarized spherical gradient illumination pattern that illuminates the object from the left side of the object; a parallel polarized spherical gradient illumination pattern illuminating the object from the left side; a cross-polarized spherical gradient illumination pattern that illuminates the object from the right side of the object; a parallel polarized spherical gradient illumination pattern illuminating the object from the right side; a cross-polarized spherical gradient illumination pattern that illuminates the object from above the object; a parallel polarized spherical gradient illumination pattern that illuminates the object from above; a cross-polarized spherical gradient illumination pattern that illuminates the object from below the object; a parallel polarized spherical gradient illumination pattern illuminating the subject from below; a cross-polarized spherical gradient illumination pattern that illuminates the object from a front side of the object; a parallel polarized spherical gradient illumination pattern illuminating the subject from the front side; a cross-polarized spherical gradient illumination pattern that illuminates the object from behind the object; or a parallel polarized spherical gradient illumination pattern illuminating the subject from the rear; The electronic device of claim 3 , comprising one or more of:

6. The circuit comprises: setting a shutter speed associated with each of the series of multi-viewpoint image capture devices based on a capture mode associated with capturing the series of images; setting a delay and a flash duration associated with the lighting system based on the determined shutter speed; synchronizing the illumination system and the series of multi-view image capture devices to capture each of the series of images of the subject based on the determined delay and flash duration. The electronic device of claim 1 further configured to:

7. the capture mode is one of a single-shot mode or a burst mode; 7. The electronic device of claim 6.

8. The circuit comprises: controlling autofocus settings associated with each of the series of multi-perspective image capture devices; controlling the series of multi-view image capture devices to capture a series of images of the subject further based on controlling the camera autofocus setting. The electronic device of claim 1 further configured to:

9. the autofocus setting corresponds to one of per-capture autofocus, per-session autofocus, or per-frame autofocus; 9. The electronic device of claim 8.

10. the first pulse corresponds to modeling light, and the first intensity corresponds to a predetermined intensity. The electronic device of claim 1 .

11. The circuit comprises: receiving a first indication that a first image has been captured from the series of images by the series of multi-view image capture devices; controlling the illumination system to illuminate the object with the first pulse associated with the first intensity based on the received first instruction; The electronic device of claim 1 further configured to:

12. The circuit comprises: receiving a second indication that capture of a second image from the series of images by the series of multi-view image capture devices has begun; controlling the illumination system to illuminate the subject with the first series of flash pulses based on the received second instruction; controlling an illumination system to illuminate the subject with the second series of flash pulses based on the illumination of the subject with the first series of flash pulses and the received second instruction; controlling the multi-view image capture device to capture the second image in the series of images based on the illumination of the subject with the second flash pulse and the received second instruction. The electronic device of claim 11 further configured to:

13. In an electronic device, selecting a sequence of illumination patterns from a plurality of predetermined illumination patterns for capturing images of the subject; controlling an illumination system associated with the electronic device to illuminate the subject with a first series of flash pulses including a first pulse and a second pulse, the illumination intensity increasing from a first intensity associated with the first pulse to a second intensity associated with the second pulse, the first intensity being less than the second intensity; controlling the illumination system based on the illumination of the object with the first series of flash pulses to illuminate the object with a second series of flash pulses corresponding to the selected series of illumination patterns, the second series of flash pulses having respective illumination intensities corresponding to the second intensity; controlling a series of multi-view image capture devices associated with the electronic device to capture each of a series of images of the subject based on illumination of the subject with the second flash pulse; A method comprising:

14. the plurality of predetermined illumination patterns correspond to one or more of an omnidirectional illumination pattern, a directional illumination pattern, a cross-polarized illumination pattern, or a parallel-polarized illumination pattern; The method of claim 13.

15. the selected set of illumination patterns corresponds to at least one of a first series of illumination patterns for shape reconstruction or a second series of illumination patterns for normal map and height map generation; The method of claim 13.

16. the first series of illumination patterns includes one or more of a cross-polarized omnidirectional illumination pattern or a parallel-polarized omnidirectional illumination pattern; 16. The method of claim 15.

17. The second series of illumination patterns comprises: a cross-polarized spherical gradient illumination pattern that illuminates the object from the left side of the object; a parallel polarized spherical gradient illumination pattern illuminating the object from the left side; a cross-polarized spherical gradient illumination pattern that illuminates the object from the right side of the object; a parallel polarized spherical gradient illumination pattern illuminating the object from the right side; a cross-polarized spherical gradient illumination pattern that illuminates the object from above the object; a parallel polarized spherical gradient illumination pattern that illuminates the object from above; a cross-polarized spherical gradient illumination pattern that illuminates the object from below the object; a parallel polarized spherical gradient illumination pattern illuminating the subject from below; a cross-polarized spherical gradient illumination pattern that illuminates the object from a front side of the object; a parallel polarized spherical gradient illumination pattern illuminating the subject from the front side; a cross-polarized spherical gradient illumination pattern that illuminates the object from behind the object; or a parallel polarized spherical gradient illumination pattern illuminating the subject from the rear; 16. The method of claim 15, comprising one or more of:

18. setting a shutter speed associated with each of the series of multi-viewpoint image capture devices based on a capture mode associated with capturing the series of images; setting a delay and flash duration associated with the lighting system based on the determined shutter speed; synchronizing the lighting system and the series of multi-view image capture devices to capture each of a series of images of the subject based on the determined delay and flash duration; 14. The method of claim 13, further comprising:

19. controlling autofocus settings associated with each of the series of multi-viewpoint image capture devices; controlling the series of multi-view image capture devices to capture each of the series of images of the subject further based on controlling the camera autofocus setting; 14. The method of claim 13, further comprising:

20. A non-transitory computer-readable medium having stored thereon computer-executable instructions that, when executed by an electronic device, selecting a sequence of illumination patterns from a plurality of predetermined illumination patterns for capturing images of the subject; controlling an illumination system associated with the electronic device to illuminate the subject with a first series of flash pulses including a first pulse and a second pulse, the illumination intensity increasing from a first intensity associated with the first pulse to a second intensity associated with the second pulse, the first intensity being less than the second intensity; controlling the illumination system based on the illumination of the object with the first series of flash pulses to illuminate the object with a second series of flash pulses corresponding to the selected series of illumination patterns, the second series of flash pulses having respective illumination intensities corresponding to the second intensity; controlling a series of multi-view image capture devices associated with the electronic device to capture each of a series of images of the subject based on illumination of the subject with the second flash pulse; 10. A non-transitory computer-readable medium for causing the electronic device to perform operations including:

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