Patent Description:
<CIT> describes the preamble of claim <NUM>, it regards a control apparatus for a cabin of an aircraft or spacecraft, which apparatus comprises a first control device for actuating at least one camera by at least a first control signal, which control device is configured to provide the first control signal as a function of at least a second control signal for actuating at least one lighting device of the cabin. <CIT> discloses a multifunction control illumination device implementing a camera. <CIT> describes an illumination apparatus with an illumination source with a pulsed illumination output structure; and a capture sensor with an image capture structure synchronized with and responsive to reflection signals generated by the pulsed illumination output signal structure. <CIT> describes a method for detecting, in a digital video recording device, video recapture of video images displayed through an image rendering device in which light intensity is controlled through periodic variation of a light intensity of a light source. <CIT> describes a method for operating a camera of a motor vehicle, in which an environmental region of the motor vehicle is captured by means of the camera, wherein an illumination source is operated pulsed with a preset pulse frequency in a periphery of the motor vehicle and wherein the pulse frequency is determined and at least one setup parameter of the camera is adapted depending on the pulse frequency. <CIT> describes a traffic monitoring system with a camera system configured to capture images of vehicles.

In one aspect, embodiments of the inventive concepts disclosed herein are directed to an aircraft system as outlined by the characterizing features of claim <NUM>. Further details of the aircraft system according to the invention are described in claims <NUM>-<NUM>. The aircraft system includes a light device and a camera. The light device is configured to emit light having a lighting frequency defined by on states and off states of the light device. The camera is in view of the emitted light. The camera has an image acquisition frequency configured to capture all images during the on states of the light device. The system preferably comprises controlling and/or synchronization means to synchronize the lighting frequency and the image acquisition frequency to enhance brightness (and the consistency thereof) of images captured by the camera.

The aircraft system implements a camera that includes an image sensor and a processor. The image sensor is in view of emitted light from a light device, the emitted light having a lighting frequency defined by on states and off states of the light device. The image sensor has an image acquisition frequency and is configured to capture images. The processor is communicatively coupled to the image sensor. The processor is configured to control the image sensor such that the image sensor captures all images during the on states of the light device. The method not belonging to the invention includes controlling, by a processor, an image sensor of a camera, the image sensor in view of emitted light from a light device, the emitted light having a lighting frequency defined by on states and off states of the light device, the image sensor having an image acquisition frequency. The method also includes capturing, by the image sensor of the camera, all images during the on states of the light device. The system of camera may comprise features of the respective preferred embodiments thereof. In the drawings:.

Broadly, embodiments of the inventive concepts disclosed herein are directed to a system, apparatus, and method for synchronizing an image acquisition frequency and timing thereof of a camera with a lighting frequency and timing thereof of at least one light device so that the camera captures all images during on states of the at least one light device. For example, a lighting system (e.g., an aircraft cabin lighting system) has the lighting system's pulse width modulation (PWM) frequency and timing synchronized (e.g., aligned) with a camera's image acquisition frequency and timing so that there are no flicker artifacts, rolling shutter (e.g., aliasing), or black frames (e.g., where light emitting diodes (LEDs) are off during image acquisition). Some embodiments may include a lighting controller sending a synch signal (e.g., a synch line) to a camera so as to cause the camera to acquire images during a leading edge of a PWM cycle when the lights are in an on state. Similarly, some embodiments may include a camera sending a synch signal (e.g., a synch line) to a lighting controller so as to cause lights to be in a leading edge of a PWM cycle (when the lights are in an on state) when the camera is scheduled to acquires images.

Embodiments include connecting a camera with a lighting system to cause alignment with the camera's image acquisition and on states of light devices. In some embodiments, a lighting controller may output a synch signal to a camera to cause synchronization of light devices with the camera, while in other embodiments, the camera may output a synch signal to a lighting controller to cause synchronization of light devices with the camera. Embodiments allow the camera to align the camera's frames with on states of light devices so as to avoid image flicker and other artifacts, and embodiments may maintain bright and clear images even when the environment appears dimly lit to humans because images are acquired during an on state portion (e.g., a leading on state edge) of a PWM flash. Due to such synchronization, an aircraft cabin may always be consistently and brightly lit during a camera's image acquisitions even when the cabin appears dimly lit to humans. Such synchronization can be performed with reading lights, ceiling lights, sidewall lights, and/or other feature lights to maintain a coherent, camera friendly environment. Additionally, some embodiments may include infrared (IR) LEDs configured to emit IR light and an IR camera configured to capture IR images to allow night vision of the cabin, such as when the cabin lighting is in night mode.

Additionally, in some embodiments, if a camera's image acquisition frequency is too slow (e.g., less than <NUM> Hertz (Hz)), a frequency multiplying method can be applied. For example, the camera can be configured to perform a synchronized image acquisition for one out of every two PWM flashes, one out of every three PWM flashes, one out of every four PWM flashes, etc. This keeps the frequency of the PWM flashes above the flicker fusion frequency of human vision and allows for the synchronization of an image acquisition frequency and timing thereof of a camera with a lighting frequency and timing thereof of a light device so that the camera captures all images during on states of the at least one light device, even though the image acquisition frequency is less than (e.g., ½ of, <NUM>/<NUM> of, ¼ of,. or <NUM>/n of (where n is an integer)) the lighting frequency.

Referring now to <FIG>, an exemplary embodiment of a system (e.g., a vehicular system (e.g., an aircraft system)) implemented in a vehicle (e.g., an aircraft <NUM>) according to the inventive concepts disclosed herein. While <FIG> exemplarily depict an aircraft system implemented on the aircraft <NUM>, some embodiments may be implemented as any suitable vehicular system (e.g., an automobile system, a train system, and/or a ship system) implemented in any suitable vehicle (e.g., an automobile, a train, and/or a ship).

The aircraft <NUM> may include at least one lighting controller <NUM>, at least one light device (e.g., at least one LED light device <NUM>), at least one camera <NUM>, at least one IR camera <NUM>, and at least one computing device, some or all of which may be communicatively coupled at any given time. While the aircraft <NUM> exemplarily includes elements as shown, in some embodiments, one or more of the elements of the aircraft <NUM> may be omitted, or the aircraft <NUM> may include other elements.

The light devices (e.g., the LED light devices <NUM>, which may include LEDs) are configured to emit light having a lighting frequency defined by on states and off states of the light devices. That is, the light devices may repeat cycles of being in an on state followed by being in an off state. In some embodiments, the lighting frequency is a PWM frequency. The lighting frequency may be adjustable, such as by the lighting controller <NUM>, so as to cause lighting to appear dimmer or brighter to humans. In some embodiments, the light devices may have synchronized lighting frequencies such that the on states and off states are synchronized for all of the light devices. In some embodiments, the light devices may be controlled by the lighting controller <NUM>. For example, the PWM frequency (e.g., so as to dim or brighten the perceived light) and a timing thereof (e.g., by shifting a phase of lighting cycles) may be controlled by the lighting controller <NUM>. In some embodiments, some of the light devices may be implemented as IR light devices (e.g., IR LED light devices) and/or may include IR lights (e.g., IR LEDs). For example, the light devices may include LED light devices <NUM> and separate IR LED light devices. For example, light bars (or any other light assemblies, such as reading lights) may include the LED light devices <NUM> and the IR LED light devices, where each light bar is part of a red green blue white IR (RGBW(IR)) string such that the camera <NUM> and/or the camera <NUM> may be configured to capture images across the visible and IR spectrum.

The lighting controller <NUM> may include at least one processor <NUM>, memory <NUM>, and at least one storage device <NUM>, as well as other components, equipment, and/or devices commonly included in a computing device, some or all of which may be communicatively coupled at any given time, as shown in <FIG>. The processor <NUM> may be implemented as any suitable processor, such as a general purpose processor, a field-programmable gate array (FPGA), and/or an image processor. For example, the lighting controller <NUM> may be configured to control the lighting frequency (e.g., so as to dim or brighten the perceived light) and a timing thereof (e.g., by shifting a phase of lighting cycles) of the light devices.

In some embodiments, the lighting controller <NUM> may be configured to obtain an image acquisition frequency and a timing (e.g., a phase at a point in time of the image acquisition cycle) thereof from the camera <NUM> and to synchronize the lighting frequency of the light devices with the image acquisition frequency of the camera <NUM> such that the camera <NUM> captures all images during the on states (e.g., during leading edges of the on states) of the light devices. The image acquisition frequency and the timing thereof may be obtained as a synch signal (e.g., a synch line).

In some embodiments, the lighting controller <NUM> may be configured to obtain and/or determine a lighting frequency and a timing (e.g., a phase at a point in time of the lighting cycle) thereof of the light devices and to output the lighting frequency and the timing thereof of the light devices to the camera <NUM>. The lighting frequency and the timing thereof may be output as a synch signal (e.g., a synch line). As such, the camera <NUM> may be configured to receive the lighting frequency and the timing thereof from the lighting controller <NUM> and to synchronize the image acquisition frequency of the camera <NUM> with the lighting frequency such that the camera <NUM> captures all images during the on states (e.g., during leading edges of the on states) of the light devices.

In some embodiments, the lighting controller <NUM> may be configured to synchronize the lighting frequency with the image acquisition frequency by adjusting (e.g., increasing or decreasing) the lighting frequency to be the same as or an n (where n is an integer greater than or equal to <NUM>) multiple of the image acquisition frequency and/or by adjusting a timing (e.g., by shifting a phase of the lighting cycle) of each lighting cycle.

The processor <NUM> may be configured to run various software applications or computer code stored (e.g., maintained) in a non-transitory computer-readable medium (e.g., memory <NUM> and/or storage <NUM>) and configured to execute various instructions or operations. For example, the processor <NUM> may be configured to perform any or all of the operations of the lighting controller <NUM>. The lighting controller <NUM> may be implemented as any suitable controller or computing device (e.g., <NUM>). In some embodiments, the lighting controller <NUM> may be implemented as a cabin lighting controller. Additionally, for example, the lighting controller <NUM> and/or the processor <NUM> may be implemented as special purpose computers or special purpose processors configured (e.g., programmed) to execute instructions for performing any or all of the operations disclosed throughout. In some embodiments, the system of <FIG> may include any suitable number of lighting controllers <NUM>. In some embodiments, the computing device <NUM> may be implemented as a lighting controller such that the lighting controller <NUM> may be omitted.

While the lighting controller <NUM> exemplarily includes elements as shown, in some embodiments, one or more of the elements of the lighting controller <NUM> may be omitted, or the lighting controller <NUM> may include other elements.

The camera <NUM> (e.g., a digital camera) may include at least one image sensor <NUM>, at least one processor <NUM>, memory <NUM>, at least one storage device <NUM>, and at least one light synch sensor <NUM>, as well as other components, equipment, and/or devices commonly included in a digital camera, some or all of which may be communicatively coupled at any given time, as shown in <FIG>. The image sensor <NUM> may be implemented as any suitable image sensor. The processor <NUM> may be implemented as any suitable processor, such as a general purpose processor, a field-programmable gate array (FPGA), and/or an image processor. The camera <NUM> may be positioned in view of emitted light from the light devices. The camera <NUM> may have an image acquisition frequency, which may be configured to capture all images during the on states of the light devices. The image acquisition frequency may be adjustable, and the processor <NUM> may be configured to control the image acquisition frequency and a timing (e.g., e.g., a phase of the image acquisition cycle) thereof. For example, the processor <NUM> may be configured to shift a phase of the image acquisition cycle to change a timing. For example, the processor <NUM> may be configured to cause the image sensor to capture images. In some embodiments, the camera <NUM> may be configured to capture images in the visible spectrum and the IR spectrum; for example, the camera <NUM> may include the image sensor <NUM> and an IR image sensor (e.g., <NUM>) or the image sensor <NUM> may be configured to capture images in the visible spectrum and the IR spectrum.

In some embodiments, the processor <NUM> may be configured to output an image acquisition frequency and a timing (e.g., a phase at a point in time of the image acquisition cycle) thereof to the lighting controller <NUM> such that the lighting controller <NUM> can synchronize the lighting frequency of the light devices with the image acquisition frequency of the camera <NUM> so that the camera <NUM> captures all images during the on states (e.g., during leading edges of the on states) of the light devices. The image acquisition frequency and the timing thereof may be output as a synch signal (e.g., a synch line).

In some embodiments, the processor <NUM> may be configured to obtain (e.g., receive) a lighting frequency and a timing (e.g., a phase at a point in time of the lighting cycle) thereof of the light devices from the lighting controller <NUM> and synchronize the image acquisition frequency with the lighting frequency such that the camera <NUM> captures all images during the on states of the light devices. The lighting frequency and the timing thereof may be obtained as a synch signal (e.g., a synch line).

In some embodiments, the processor <NUM> may be configured to obtain and/or determine a lighting frequency and a timing (e.g., a phase at a point in time of the lighting cycle) thereof of the light devices. For example, the processor <NUM> may be configured to obtain and/or determine a lighting frequency and a timing thereof based on data received from the light synch sensor <NUM>, which may be configured to detect the lighting frequency and the timing thereof. Based on the lighting frequency and the timing thereof, the processor may be configured to synchronize the image acquisition frequency with the lighting frequency such that the camera <NUM> captures all images during the on states (e.g., during leading edges of the on states) of the light devices.

The image acquisition frequency is an initial image acquisition frequency. The processor <NUM> is configured to determine that the lighting frequency of the light devices is less than the initial image acquisition frequency, to reduce a frequency of the initial image acquisition frequency to a second image acquisition frequency, and to synchronize the second image acquisition frequency with the lighting frequency such that the camera <NUM> captures all images during the on states (e.g., during leading edges of the on states) of the light devices.

The processor <NUM> is configured to synchronize the image acquisition frequency with the lighting frequency by adjusting (e.g., increasing or decreasing) the image acquisition frequency to be the same as or a <NUM>/n multiple of the lighting frequency and/or by adjusting a timing (e.g., by shifting a phase of the image acquisition cycle) of each image acquisition cycle.

The processor <NUM> may be configured to run various software applications or computer code stored (e.g., maintained) in a non-transitory computer-readable medium (e.g., memory <NUM> and/or storage <NUM>) and configured to execute various instructions or operations. For example, the processor <NUM> may be configured to perform any or all of the operations of the camera <NUM>. Additionally, for example, the processor <NUM> may be implemented as a special purpose processor configured (e.g., programmed) to execute instructions for performing any or all of the operations disclosed throughout. In some embodiments, the system of <FIG> may include any suitable number of cameras <NUM>. In some embodiments, the processor <NUM> of the computing device <NUM> may be configured to perform, at least in part, the functionality of the processor <NUM>.

The light synch sensor <NUM> may be configured to detect the lighting frequency and the timing thereof. In some embodiments, the light synch sensor <NUM> may include a processor (e.g., a controller (e.g., a microcontroller)) configured to measure the lighting frequency (e.g., a PWM frequency) and the timing thereof of sensed light such that the light synch sensor <NUM> can determine the lighting frequency and the timing thereof without being communicatively coupled to the lighting controller <NUM> (if the system includes a lighting controller). In some embodiments, the light synch sensor <NUM> may be configured to measure the lighting frequency and the timing thereof for visible light and/or IR light. The light synch sensor <NUM> may be communicatively coupled to the processor <NUM> of the camera <NUM> and configured to output detected (e.g., measured) lighting frequency and the timing thereof to the processor <NUM> of the camera <NUM>. In some embodiments, the light synch sensor <NUM> is implemented in or on the camera <NUM>; however, in some embodiments, the light synch sensor <NUM> may be implemented at any suitable position in a system (e.g., in a vehicle cabin) where the light synch sensor <NUM> is in view of light emitted from the light devices. For example, the light synch sensor <NUM> may be implemented separately from the camera <NUM>.

In some embodiments, a processor (e.g., the processor <NUM> and/or a controller of the light synch sensor <NUM>) may be configured to execute software such that the processor is configured to determine an appropriate operating mode of a plurality of operating modes (e.g., bright operating mode, medium operating mode, and dim operating mode) for the camera <NUM>, such as by locking on all light flashes (e.g., LED light flashes), locking on alternating light flashes, or recurrently locking on one of a series of light flashes (e.g., one of every n light flashes). As such, in some embodiments, the camera <NUM> may be retrofitted, without modifying or replacing legacy lighting systems, so as to achieve a synchronized camera and lighting system.

While the camera <NUM> exemplarily includes elements as shown, in some embodiments, one or more of the elements of the camera <NUM> may be omitted, or the camera <NUM> may include other elements.

The IR camera <NUM> (e.g., a digital IR camera) may include at least one IR image sensor <NUM>, at least one processor <NUM>, memory <NUM>, at least one storage device <NUM>, and at least one light synch sensor (not shown), as well as other components, equipment, and/or devices commonly included in a digital IR camera, some or all of which may be communicatively coupled at any given time, as shown in <FIG>. The image sensor <NUM> may be implemented as any suitable IR image sensor. The IR camera <NUM> may be implemented similarly as and have functionality similarly to the camera <NUM>, except that the IR camera <NUM> is configured to capture IR images. For example, similar to the camera <NUM>, an IR image acquisition frequency of the IR camera <NUM> may be synchronized with an IR lighting frequency of IR light devices such that the camera <NUM> captures all IR images during the on states (e.g., during leading edges of the on states) of the IR light devices. Additionally, for example, the IR camera <NUM> may be configured to capture IR images when the lighting frequency of the light devices is less than the image acquisition frequency.

While the IR camera <NUM> exemplarily includes elements as shown, in some embodiments, one or more of the elements of the IR camera <NUM> may be omitted, or the IR camera <NUM> may include other elements.

In some embodiments, the IR camera <NUM> may be omitted. For example, the camera <NUM> may be configured to sense light in the IR spectrum and capture IR images. For example, the camera <NUM> may have sensitivity to IR light and be configured to capture black and white images based on sensed IR light.

The computing device <NUM> may include at least one processor <NUM>, at least one memory <NUM>, and at least one storage device <NUM>, as well as other components, equipment, and/or devices commonly included in a computing device, some or all of which may be communicatively coupled. The processor <NUM> may be implemented as any suitable processor, such as a general purpose processor, an FPGA, and/or an image processor. For example, the computing device <NUM> may be configured to control the lighting controller <NUM>, the camera <NUM>, and the IR camera <NUM>. For example, the processor <NUM> may be configured to receive user input data to change a dimness or a brightness of the light devices, and the processor <NUM> may output an instruction to the lighting controller <NUM> to change the dimness or brightness of the light devices. Likewise, the lighting controller <NUM> and/or the camera <NUM> may respond such that the lighting frequency and the image acquisition frequency remain aligned, such as disclosed throughout. The processor <NUM> may be configured to run various software applications or computer code stored (e.g., maintained) in a non-transitory computer-readable medium (e.g., memory <NUM> and/or storage <NUM>) and configured to execute various instructions or operations. The computing device <NUM> may be implemented as any suitable computing device. In some embodiments, the computing device <NUM> is implemented as a vetronics computing device (e.g., an avionics computing device) in a vehicle, such as the aircraft <NUM>, an automobile, or a train, resulting in a vehicle, for example an aircraft, comprising a system and/or a camera according to the first and second aspect, respectively, of the invention as discussed herein before and as claimed. Such a vehicle is claimed as well. Additionally, for example, the computing device <NUM> or the processor <NUM> may be implemented as special purpose computers or special purpose processors configured (e.g., programmed) to execute instructions for performing any or all of the operations disclosed throughout. In some embodiments, the system of <FIG> may include any suitable number of computing devices <NUM>.

While the computing device <NUM> exemplarily includes elements as shown, in some embodiments, one or more of the elements of the computing device <NUM> may be omitted, or the computing device <NUM> may include other elements.

Referring now to <FIG>, an exemplary graph of an LED lighting cycle at <NUM>% LED power output compared to image acquisition cycles (e.g., camera frame acquisition cycles) of a camera is shown. As shown in <FIG>, the LED is at <NUM>% power output such that the LED is always in an on state. The image acquisitions (as shown by peaks in <FIG>) occur while the LED is in an on state such that the camera captures all images during an on state of the LED.

Referring now to <FIG>, an exemplary graph of LED lighting cycles at <NUM>% LED power output compared to image acquisition cycles (e.g., camera frame acquisition cycles) of a camera, according to inventive concepts disclosed herein, is shown. As shown in <FIG>, the LED is at <NUM>% power output such that the LED is operating half the time in on states during the peaks and operating half the time in off states during the valleys. The image acquisition frequency is aligned with the light frequencies such that the image acquisitions (as shown by peaks in <FIG>) occur during the leading edge of the on state of each LED lighting cycle. Each image acquisition occurs while the LED is in an on state such that the camera captures all images during on states of the LED so as to avoid flicker and other artifacts. An advantage of synchronizing the image acquisitions to being aligned with leading edges of on states of the LED may be that the image acquisition remains synchronized with the on states of the light devices even if a duration of each on state is reduced (e.g., so as to dim the light devices).

Referring now to <FIG>, exemplary overlaid graphs of LED lighting cycles at various LED power outputs compared to various image acquisition cycles of a camera, according to inventive concepts disclosed herein, are shown. The top graph shows an LED lighting cycle at <NUM>% LED power output compared to image acquisition cycles of a camera configured for capturing <NUM> frames per second, similar to <FIG>. The second graph shows LED lighting cycles at <NUM>% LED power output compared to image acquisition cycles of a camera configured for capturing <NUM> frames per second, similar to <FIG>. The third graph shows LED lighting cycles at <NUM>% LED power output compared to image acquisition cycles of a camera configured for capturing <NUM> frames per second. The fourth graph shows LED lighting cycles at <NUM>% LED power output compared to image acquisition cycles of a camera configured for capturing <NUM> frames per second. With respect to the fourth graph, as the LED dims to a low level and approaches the camera's image acquisition duration, the mode of the LED system may changes from a PWM mode to a pulse-frequency modulation (PFM) mode, which lengthens the lighting cycle (by increasing the amount of time between on states) to achieve a lower dim level while still allowing each image acquisition to fully occur during an on state of the LED. For second, third, and fourth graphs, the image acquisition frequency is aligned with the lighting frequency such that the image acquisitions (as shown by peaks in <FIG>) occur during the leading edge of the on state of each LED lighting cycle.

Referring now to <FIG>, an exemplary embodiment of a method <NUM> according to the inventive concepts disclosed herein may include one or more of the following steps. Additionally, for example, some embodiments may include performing one more instances of the method <NUM> iteratively, concurrently, and/or sequentially.

A step <NUM> includes controlling, by a processor, an image sensor of a camera, the image sensor in view of emitted light from at least one light device, the emitted light having a lighting frequency defined by on states and off states of the at least one light device, the image sensor having an image acquisition frequency.

A step <NUM> includes capturing, by the image sensor of the camera, all images during the on states of the at least one light device.

As will be appreciated from the above, embodiments of the inventive concepts disclosed herein may be directed to a method, a lighting system, and a camera, wherein the lighting system is synchronized with the camera such that the camera captures all images during on states of the lighting system.

As used throughout and as would be appreciated by those skilled in the art, "at least one non-transitory computer-readable medium" may refer to as at least one non-transitory computer-readable medium (e.g., memory <NUM>, memory <NUM>, memory <NUM>, memory <NUM>, storage <NUM>, storage <NUM>, storage <NUM>, storage <NUM>, or a combination thereof; e.g., at least one computer-readable medium implemented as hardware; e.g., at least one non-transitory processor-readable medium, at least one memory (e.g., at least one nonvolatile memory, at least one volatile memory, or a combination thereof; e.g., at least one random-access memory, at least one flash memory, at least one read-only memory (ROM) (e.g., at least one electrically erasable programmable read-only memory (EEPROM)), at least one on-processor memory (e.g., at least one on-processor cache, at least one on-processor buffer, at least one on-processor flash memory, at least one on-processor EEPROM, or a combination thereof), or a combination thereof), at least one storage device (e.g., at least one hard-disk drive, at least one tape drive, at least one solid-state drive, at least one flash drive, at least one readable and/or writable disk of at least one optical drive configured to read from and/or write to the at least one readable and/or writable disk, or a combination thereof), or a combination thereof).

Claim 1:
An aircraft system (<NUM>), wherein the aircraft system comprises:
at least one light device (<NUM>), configured to emit light having a lighting frequency defined by on states and off states of the at least one light device (<NUM>);
a camera (<NUM>, <NUM>) wherein the camera comprises:
an image sensor (<NUM>, <NUM>) in view of emitted light from the at least one light device (<NUM>), the image sensor (<NUM>, <NUM>) having an image acquisition frequency, the image sensor (<NUM>, <NUM>) configured to capture images; and
a processor (<NUM>, <NUM>) communicatively coupled to the image sensor (<NUM>, <NUM>), the processor configured to control the image sensor (<NUM>, <NUM>) such that the image sensor (<NUM>, <NUM>) captures all images during the on states of the at least one light device (<NUM>),
characterized in that
the image acquisition frequency is an initial image acquisition frequency; and
the processor is further configured to:
determine whether the lighting frequency of the at least one light device (<NUM>) is less than the initial image acquisition frequency;
when the lighting frequency is less than the initial image acquisition frequency, reduce the initial image acquisition frequency to a second image acquisition frequency;
synchronize the second image acquisition frequency with the lighting frequency by adjusting the second image acquisition frequency to be the same as or a <NUM>/n multiple of the lighting frequency, wherein n is an integer greater than or equal to <NUM>, such that the camera (<NUM>, <NUM>) captures all images during the on states of the at least one light device (<NUM>), so that there are no flicker artifacts, rolling shutter or black frames.