Patent Description:
An image sensor is one of main components of a terminal photographing system, and plays a decisive role in imaging quality. Currently, a commonly used color imaging sensor is a Bayer sensor. To obtain a full-color image, the Bayer sensor needs perform interpolation and supplement by using a demosaicing algorithm. This causes a reduction in image resolution. In addition, problems such as a moiré pattern, color noise, and zippering noise are often caused in the interpolation process, and therefore imaging quality is degraded.

With development and popularization of intelligent terminal technologies, people have growing requirements on photographing experience of intelligent terminals. Users expect to obtain higher photographing quality.

Therefore, how to improve imaging quality of an image becomes a problem that urgently needs to be resolved. <CIT> discloses infrared (IR) camera systems for and a method of obtaining infrared images of target subjects. In one embodiment, an IR camera system includes a lens, a number of IR pass filters, an optical detector, a processor mounted on a circuit board, a distance sensor, a visible light sensor, an IR light sensor, an IR illuminator, and a number of video outputs, all of which may be disposed within an appropriately configured housing. The filters are mounted on a juke-box like rack system also included within the housing. The processor determines which pass filter is needed in order to optimize the image and sends an electronic signal to the rack system directing the rack system to move the appropriate filter into the optical pathway between the lens and the optical detector and pull all of the other IR filters out of the optical pathway between the lens and the optical detector
<CIT> discloses an imaging system for color image acquisition including: an image sensor, a tunable spectral filter arranged in an optical path of light propagation towards the image sensor, and a controller connected to the image sensor and to the tunable spectral filter. The controller is configured and operable for generating a colored image by sequentially operating the tunable spectral filter for sequentially filtering light passing towards the image sensor with three or more different spectral filtering curves during three or more corresponding integration time durations. The tunable spectral filter is configured, as an etalon and includes a pair of reflective surfaces. At least one of the reflective surfaces includes a layer of high refractive index of at least n=<NUM> or even higher than <NUM>, or a layer of low refractive index, smaller than n=<NUM>. The configuration of the etalon provide wide transmission peaks of the spectral curves with full-width-half maximum (FWHM) in the range of about <NUM> to <NUM>, free spectral range (FSR) of at least <NUM>, and thickness of the etalon in the order to <NUM> or even less.

This application provides an imaging system of claim <NUM>, to improve imaging quality of an image.

The following first describes an imaging principle: An optical image generated from a scene by using a lens is projected onto a surface of an image sensor. The image sensor converts an optical signal into an electrical signal, analog-to-digital conversion processing is performed on the electrical signal to obtain a digital image signal, the digital image signal is processed by a processor, and then a processed image is transmitted to a display for view.

Most colors in the nature are usually obtained by mixing several monochrome colors such as three primary colors of red, green, and blue based on a specific proportion. Therefore, to obtain a color image, monochrome images of several primary colors need to be obtained first, and then the monochrome images are mixed based on a specific proportion to obtain the color image.

With reference to <FIG>, the following uses an example in which monochrome colors are three primary colors of red, green, and blue, to describe an implementation of obtaining monochrome images of a scene based on a Bayer array filter. As shown in <FIG>, in the Bayer array filter, a sensor of red, green, and blue band light is arranged in a chessboard shape. Therefore, in images obtained after a scene is projected onto the sensor by using the Bayer array filter, three colors of red, green, and blue are arranged in a chessboard shape, and monochrome images corresponding to the three colors of red, green, and blue are shown in <FIG>.

As shown in <FIG>, each monochrome image includes only a part of data. To obtain complete monochrome images of red, green, and blue, an interpolation operation needs to be performed on a monochrome color based on each monochrome image shown in <FIG>, to obtain complete monochrome images that are shown in <FIG> and that respectively include only red, green, and blue.

A color image restored from the three monochrome images obtained through the interpolation operation has relatively low resolution. In addition, problems such as a moiré pattern, color noise, and zippering noise are further caused in the interpolation process, and therefore imaging quality is also degraded.

To improve imaging quality of an image, this application provides a new filter, a camera module, an imaging system, and an imaging method.

<FIG> is a schematic diagram of an architecture of an imaging system <NUM> according to an embodiment of this application. The imaging system <NUM> includes a camera module <NUM> and a processing module <NUM>. Optionally, the imaging system <NUM> may further include a storage module <NUM> and a display module <NUM>.

The camera module <NUM> includes a filter module <NUM> and a sensor module <NUM>. The processing module <NUM> may include an image signal processor <NUM> and a filter control unit <NUM>. The filter module <NUM>, the filter control unit <NUM>, the sensor module <NUM>, the image signal processor <NUM>, the storage module <NUM>, and the display module <NUM> communicate with each other, in other words, transmit signals or data, by using a bus system <NUM>.

The filter module <NUM> is configured to: receive a control signal output by the filter control unit <NUM>, and output optical signals of different bands in incident light to a same pixel on the sensor module at different times under control of the control signal. The optical signals output by the filter module <NUM> include an optical signal of a band required for completing imaging by the imaging system <NUM>. For example, when a spectral mode of the imaging system <NUM> is an RGB mode, required bands include red, green, and blue bands; when a spectral mode of the imaging system <NUM> is an RYB mode, required bands include red, yellow, and blue bands; when a spectral mode of the imaging system <NUM> is an RWB mode, required bands include red and blue bands and a full band; when a spectral mode of the imaging system <NUM> is an RGBW mode, required bands include red, green, and blue bands and a full band; and in other special spectral modes, required bands may include a near infrared light band in addition to a visible light band. For ease of description, the optical signal of the required band is referred to as a target optical signal.

The sensor module <NUM> is configured to: convert, into electrical signals, optical signals incident through the filter module <NUM>, and output the electrical signals. A process in which the sensor module <NUM> converts the optical signal into the electrical signal may also be referred to as photosensitive imaging. A process in which the sensor module <NUM> continuously converts optical signals into electrical signals may be referred to as continuous integration of the optical signals.

Optionally, the sensor module <NUM> may perform, under control of the control unit, optical-to-electrical signal conversion only when the filter module <NUM> outputs the target optical signal; or may perform optical-to-electrical signal conversion on all optical signals output by the filter module <NUM>. In the latter case, the image signal processor <NUM> may select, from the electrical signals output by the sensor module <NUM>, an electrical signal obtained by converting the target optical signal. The electrical signals output by the sensor module <NUM> may be referred to as raw image data.

An example of the sensor module <NUM> is a full-band pass sensor. Photosensitive imaging can be performed for visible light on each pixel of the full-band pass sensor, or photosensitive imaging can be performed for visible light and near infrared light on each pixel of the full-band pass sensor.

The image signal processor (image signal processor, ISP) <NUM> is configured to process the electrical signals output by the sensor module <NUM>, to obtain a color image. The image signal processor <NUM> is configured to perform the following processing on the raw image data: white balance (white balance, WB), color restoration (color correction, CC), gamma (gamma) correction, and three-dimensional look-up table (<NUM> dimensions look-up-table, 3D Lut) correction, to implement color-related tuning to obtain a full-color image.

The filter control unit <NUM> is configured to output a control signal to the filter module <NUM>, to control the filter module <NUM> to output target optical signals of different bands in incident light through filtering at different times.

The storage module <NUM> is configured to store program code to be executed by the processing module <NUM> and/or image-related data, for example, raw image data collected by the sensor module <NUM>, temporary data obtained when the processing module <NUM> performs color tuning on the raw image data, and a color image obtained through color tuning.

The storage module <NUM> may be a read-only memory (read-only memory, ROM), a static storage device, a dynamic storage device, a random access memory (random access memory, RAM), or the like.

The display module <NUM> is configured to display the color image obtained by the image signal processor <NUM> through processing. The display module <NUM> may be a liquid crystal display (liquid crystal display, LCD), a light emitting diode (light emitting diode, LED) display device, a cathode ray tube (cathode ray tube, CRT) display device, a projector (projector), or the like.

In the imaging system shown in <FIG>, demosaicing processing does not need to be performed, so that image resolution can be increased, and a moiré pattern can be avoided. The filter module <NUM> can provide finer spectral raw data, and the processing module <NUM> can provide a high-dimensional CCM matrix, to ensure multi-degree of freedom in color tuning and ensure color restoration accuracy.

<FIG> is a schematic diagram of an architecture of an imaging system <NUM> according to another embodiment of this application. As shown in <FIG>, the imaging system <NUM> may include the components of the imaging system <NUM>, and in addition, the camera module <NUM> in the imaging system <NUM> may further include a lens module <NUM>.

The lens module <NUM> may be further configured to enable the target optical signal output by the filter module <NUM> to cover a larger area of a photosensitive region of the sensor module <NUM>, for example, to just cover the photosensitive region of the sensor module <NUM>. An angle at which an optical signal passing through the lens module <NUM> is incident on the filter module <NUM> is less than an angle at which the optical signal is incident on the filter module <NUM> when there is no lens module <NUM>. In other words, the lens module <NUM> may be intended to reduce an angle at which the optical signal is incident on the filter module <NUM>. In this way, the lens module <NUM> reduces a problem of a color deviation generated by the filter module <NUM> in a case of large-angle incidence, and also ensures that more optical signals are incident on the sensor module <NUM>, so that imaging quality can be further improved.

It may be understood that the lens module <NUM> is located before the filter module <NUM>, and the lens module <NUM> may be further configured to: collect optical signals or an optical signal transmitted or reflected by a target object and/or a target scene, and output the optical signals or the optical signal to the filter module <NUM>.

The lens module <NUM> may include but is not limited to the following lens components: a plastic lens group, a plastic-glass hybrid lens group, a diffractive optical element (diffractive optical elements, DOE) lens, a metalens (metalens), or another lens. It may be understood that the lens module <NUM> includes three lenses only as an example, and the lens module <NUM> may include more or less lenses or more types of lenses.

<FIG> is a schematic diagram of an architecture of an imaging system <NUM> according to another embodiment of this application. As shown in <FIG>, the imaging system <NUM> may include the components of the imaging system <NUM>, and in addition, the camera module <NUM> in the imaging system includes a motor module <NUM>, and the processing module <NUM> may further include a motor control unit <NUM>.

The motor module <NUM> is specifically configured to: receive a control signal output by the motor control unit <NUM>, and move the lens module <NUM> based on the control signal, to adjust a relative position between the lens module <NUM> and the sensor module <NUM>, for example, adjust a distance between the lens module <NUM> and the sensor module <NUM> in an optical axis direction of a lens, to implement a focusing function, and adjust the relative position between the lens module <NUM> and the sensor module <NUM> in a direction perpendicular to the optical axis direction, to implement optical image stabilization.

The motor module <NUM> may include but is not limited to the following types of motors: a voice coil motor (voice coil motor, VCM), a shape-memory alloy (shape-memory alloy, SMA) motor, a piezo (Piezo) motor, or a micro-electro-mechanical system (microelectro mechanical system, Mems) motor.

In this embodiment of this application, the filter module is independent of focusing and optical image stabilization functions, and therefore optical image stabilization performance is not sacrificed.

<FIG> is a schematic diagram of an architecture of an imaging system <NUM> according to another embodiment of this application. As shown in <FIG>, the imaging system <NUM> may include the components of the imaging system <NUM>. Differences are as follows: The motor module <NUM> is specifically configured to: receive a control signal output by the motor control unit <NUM>, and move the sensor module <NUM> based on the control signal, to adjust a relative position between the lens module <NUM> and the sensor module <NUM>, for example, adjust a distance between the lens module <NUM> and the sensor module <NUM> in an optical axis direction of a lens, to implement a focusing function, and adjust the relative position between the lens module <NUM> and the sensor module <NUM> in a direction perpendicular to the optical axis direction of the lens, to implement optical image stabilization.

<FIG> is a schematic diagram of an architecture of an imaging system <NUM> according to another embodiment of this application. As shown in <FIG>, the imaging system <NUM> may include the components of the imaging system <NUM>. Differences are as follows: The motor module <NUM> is specifically configured to: receive a control signal output by the motor control unit <NUM>, and move the lens module <NUM> and the sensor module <NUM> based on the control signal, to adjust a relative position between the lens module <NUM> and the sensor module <NUM>, for example, adjust a distance between the lens module <NUM> and the sensor module <NUM> in an optical axis direction of a lens, to implement a focusing function, and adjust the relative position between the lens module <NUM> and the sensor module <NUM> in a direction perpendicular to the optical axis direction, to implement optical image stabilization. In addition, the motor module <NUM> can move both the lens module <NUM> and the sensor module <NUM>, so that focusing and image stabilization can be quickly implemented.

<FIG> is a schematic diagram of an architecture of an imaging system <NUM> according to another embodiment of this application. As shown in <FIG>, the imaging system <NUM> may include the components of the imaging system <NUM>. Differences are as follows: A position of the lens module <NUM> in the imaging system <NUM> is different from that of the lens module <NUM> in the imaging system <NUM>. Specifically, the lens module <NUM> in the imaging system <NUM> is located between the filter module <NUM> and the sensor module <NUM>.

<FIG> is a schematic diagram of an architecture of an imaging system <NUM> according to another embodiment of this application. As shown in <FIG>, the imaging system <NUM> may include the components of the imaging system <NUM>. Differences are as follows: The imaging system <NUM> includes at least one more lens module <NUM> than the imaging system <NUM>, and the lens module <NUM> is located on a side that is of the filter module <NUM> and that is away from the sensor module <NUM>.

<FIG> is a schematic diagram of an architecture of an imaging system <NUM> according to another embodiment of this application. As shown in <FIG>, the imaging system <NUM> may include the components of the imaging system <NUM>. Differences are as follows: The motor module <NUM> in the imaging system <NUM> is configured to: receive a control signal output by the motor control unit <NUM>, and move, based on the control signal, the sensor module <NUM> and the lens module <NUM> on the side that is of the filter module <NUM> and that is away from the sensor module <NUM>, to adjust a relative position between the lens module <NUM> and the sensor module <NUM>, so that focusing and image stabilization can be quickly implemented.

The foregoing describes schematic structures of the imaging system provided in this application. The following describes structures of a filter module provided in this application. Before the filter module provided in this application is described, an optical aperture in the imaging system of this application is first described.

<FIG> is a schematic diagram of a structure of a camera module according to an embodiment of this application. As shown in <FIG>, a camera module <NUM> includes a lens <NUM>, a filter module <NUM>, and a sensor module <NUM>. In <FIG>, a dashed-line cylinder region is centered on a normal line of the lens <NUM> and the sensor module <NUM>, and the dashed-line cylinder region is an optical aperture <NUM>.

It may be understood that the camera module <NUM> includes the lens <NUM>, the filter module <NUM>, and the sensor module <NUM> only as an example. Actually, a structure of the camera module <NUM> may be a structure of a camera module in any one of the foregoing imaging systems. For example, the camera module <NUM> may further include a motor module, or another lens module may be included between the filter <NUM> and the sensor module <NUM>, or the lens <NUM> may not be included.

In addition, it may be understood that a shape of the filter module <NUM> shown in <FIG> is only an example, and the filter module <NUM> may be a filter module shown in any one of <FIG>.

<FIG> is a schematic diagram of a structure of a filter module <NUM> according to an embodiment of this application. The filter module <NUM> may be a filter module in a camera module shown in any one of <FIG>.

The filter module <NUM> includes a red narrowband filter <NUM>-<NUM>, a green narrowband filter <NUM>-<NUM>, a blue narrowband filter <NUM>-<NUM>, and a high-speed electric wheel <NUM>-<NUM>. The red narrowband filter <NUM>-<NUM>, the green narrowband filter <NUM>-<NUM>, and the blue narrowband filter <NUM>-<NUM> are installed on the high-speed electric wheel <NUM>-<NUM>. The high-speed electric wheel <NUM>-<NUM> is not transparent, and only the narrowband filters are transparent.

A working principle of the filter module <NUM> is as follows: The high-speed electric wheel receives a control signal output by a filter control unit, and rotates at a high speed under control of the control signal, to drive the red narrowband filter <NUM>-<NUM>, the green narrowband filter <NUM>-<NUM>, and the blue narrowband filter <NUM>-<NUM> to rotate. Because a position of an optical aperture <NUM>-<NUM> is fixed, the red narrowband filter <NUM>-<NUM>, the green narrowband filter <NUM>-<NUM>, and the blue narrowband filter <NUM>-<NUM> alternately cover the optical aperture <NUM>-<NUM> when being driven by the high-speed electric wheel. When each of the red narrowband filter <NUM>-<NUM>, the green narrowband filter <NUM>-<NUM>, and the blue narrowband filter <NUM>-<NUM> covers the optical aperture <NUM>-<NUM>, the optical aperture <NUM>-<NUM> outputs a target optical signal of a corresponding band. In other words, the target optical signal output by the filter module <NUM> is switched between red, green, and blue bands through high-speed rotation of the high-speed electric wheel.

<FIG> is a schematic diagram of a structure of a filter module <NUM> according to another embodiment of this application. The filter module <NUM> includes a red narrowband filter <NUM>-<NUM>, a green narrowband filter <NUM>-<NUM>, a blue narrowband filter <NUM>-<NUM>, and a high-speed electric wheel <NUM>-<NUM>. The red narrowband filter <NUM>-<NUM>, the green narrowband filter <NUM>-<NUM>, and the blue narrowband filter <NUM>-<NUM> are installed on the high-speed electric wheel <NUM>-<NUM>. The high-speed electric wheel <NUM>-<NUM> is not transparent. The filter module <NUM> is a drawer push-pull mechanical switching structure. For example, in a time period, the red narrowband filter <NUM>-<NUM> is pushed by the high-speed electric wheel <NUM>-<NUM> to a channel on which an optical aperture is located, and the other filters are pulled out of the channel on which the optical aperture is located. The filter module <NUM> may be a filter module in a camera module shown in any one of <FIG>.

A working principle of the filter module <NUM> is as follows: Because a position of the optical aperture <NUM>-<NUM> is fixed, the red narrowband filter <NUM>-<NUM>, the green narrowband filter <NUM>-<NUM>, and the blue narrowband filter <NUM>-<NUM> alternately cover the optical aperture <NUM>-<NUM> when being driven by a drawer-like/translation motor. When each of the red narrowband filter <NUM>-<NUM>, the green narrowband filter <NUM>-<NUM>, and the blue narrowband filter <NUM>-<NUM> covers the optical aperture <NUM>-<NUM>, the optical aperture <NUM>-<NUM> outputs a target optical signal of a corresponding band. In other words, the target optical signal output by the filter module <NUM> is switched between red, green, and blue bands through driving of the drawer-like/translation motor.

It may be understood that the filters in the filter module <NUM> or the filter module <NUM> may be filters of other bands, for example, may be a red narrowband filter, a yellow narrowband filter, and a blue narrowband filter, may be a red narrowband filter, a blue narrowband filter, and a full-band filter, or may be a red narrowband filter, a green narrowband filter, a blue narrowband filter, and a full-band filter.

Based on the filter module shown in <FIG> and <FIG>, an infrared cut-off filter covers the optical aperture <NUM>-<NUM>. Based on the filter module shown in <FIG> or <FIG>, an infrared cut-off filter covers the optical aperture <NUM>-<NUM>. The infrared cut-off filter does not rotate with the high-speed electric motor, to filter out infrared light in a target optical signal, so that imaging quality is improved. Alternatively, an infrared cut-off filter may cover a surface of a filter that cannot completely filter out infrared light, to filter out infrared light.

<FIG> is a schematic diagram of a structure of a filter module <NUM> according to another embodiment of this application. The filter module <NUM> may be a filter module in a camera module shown in any one of <FIG>.

The filter module <NUM> includes a graded interferometric thin film filter <NUM>-<NUM> and a high-speed electric wheel <NUM>-<NUM>, and the graded interferometric thin film filter <NUM>-<NUM> is fastened to the high-speed electric wheel <NUM>-<NUM>. The graded interferometric thin film filter <NUM>-<NUM> may perform continuous filtering in a visible light range. The high-speed electric wheel <NUM>-<NUM> is not transparent, and only the graded interferometric thin film filter <NUM>-<NUM> is transparent. An optical aperture of the imaging system is indicated by <NUM>-<NUM>.

In a direction of an arrow, the graded interferometric thin film filter <NUM>-<NUM> has a gradient color, and the color gradually changes from light to dark. Therefore, the graded interferometric thin film filter <NUM>-<NUM> can continuously filter light in the visible light range. For example, the graded interferometric thin film filter <NUM>-<NUM> can continuously filter light with wavelengths in a range of <NUM> nanometers to <NUM> nanometers.

As shown in <FIG>, wavelengths of light that can be transmitted by the filter <NUM>-<NUM> continuously change in the direction of the arrow by using a dotted line as a start point. In this way, when the graded interferometric thin film filter <NUM>-<NUM> continuously rotates in an opposite direction of the arrow, wavelengths of target optical signals that can be output by the filter module <NUM> through filtering continuously change.

The high-speed electric wheel <NUM>-<NUM> may drive the filter <NUM>-<NUM> to rotate only counterclockwise or clockwise, or may drive the filter to alternately rotate counterclockwise and clockwise.

For example, the high-speed electric wheel <NUM>-<NUM> may drive the filter <NUM>-<NUM> to continuously rotate counterclockwise, to implement continuous filtering.

For another example, the high-speed electric wheel <NUM>-<NUM> may drive the filter <NUM>-<NUM> to continuously rotate clockwise, to implement continuous filtering.

For another example, the high-speed electric wheel <NUM>-<NUM> drives the filter <NUM>-<NUM> to rotate clockwise after driving the filter <NUM>-<NUM> to rotate one circle counterclockwise, and then drives the filter to rotate counterclockwise after driving the filter to rotate one circle clockwise, to implement continuous filtering.

A working principle of the filter module <NUM> is similar to the working principle of the filter module <NUM>, and is not described herein again. Differences are as follows: There is always light passing through the graded filter, and a gap between two filters in the structure <NUM> does not exist.

As the graded interferometric thin film filter <NUM>-<NUM> cannot completely filter out infrared light, a separate infrared cut-off filter may be installed on the optical aperture <NUM>-<NUM>, and the infrared cut-off filter does not rotate with the wheel.

The filter module <NUM> includes a graded interferometric thin film filter <NUM>-<NUM> and a high-speed electric wheel <NUM>-<NUM>, and the graded interferometric thin film filter <NUM>-<NUM> is fastened to the motor <NUM>-<NUM>. The graded interferometric thin film filter <NUM>-<NUM> performs continuous filtering in a visible light range along a length edge. The motor <NUM>-<NUM> is not transparent, and only the graded interferometric thin film filter <NUM>-<NUM> is transparent. An optical aperture of the imaging system is indicated by <NUM>-<NUM>.

As shown in <FIG>, wavelengths of light that can be transmitted by the filter <NUM>-<NUM> continuously change in the direction of the arrow. In this way, when the graded interferometric thin film filter <NUM>-<NUM> continuously rotates in an opposite direction of the arrow, wavelengths of target optical signals that can be output by the filter module <NUM> through continuous filtering continuously change.

In some examples, the motor <NUM>-<NUM> may drive the filter <NUM>-<NUM> to move in the direction of the arrow and to move in the opposite direction of the arrow. For example, the motor <NUM>-<NUM> drives the filter <NUM>-<NUM> to move in the direction of the arrow, so that different color parts of the filter <NUM>-<NUM> slide from the optical aperture <NUM>-<NUM> from left to right. Then the motor <NUM>-<NUM> drives the filter <NUM>-<NUM> to move in the opposite direction of the arrow, so that different color parts of the filter <NUM>-<NUM> slide from the optical aperture <NUM>-<NUM> from right to left.

A working principle of the filter module <NUM> is similar to the working principle of the filter module <NUM>, and is not described herein again. Differences are as follows: The graded filter can continuously filter light, and a gap between two filters in the structure <NUM> does not exist.

As the graded interferometric thin film filter <NUM>-<NUM> cannot completely filter out infrared light, a separate infrared cut-off filter is installed on the optical aperture <NUM>-<NUM>, and the infrared cut-off filter does not rotate with the wheel.

<FIG> is a schematic diagram of a structure of a filter module <NUM> helpful for understanding the invention but not covered by the claims. The filter module <NUM> may be a filter module in a camera module shown in any one of <FIG>.

The filter module <NUM> includes a reflector <NUM>-<NUM>, a reflector <NUM>-<NUM>, a high-speed moving motor <NUM>-<NUM>, and a fastening structure <NUM>-<NUM>. The reflector <NUM>-<NUM> and the reflector <NUM>-<NUM> are sequentially arranged in an optical axis direction. An optical axis may be understood as a center line of a light pillar (a beam) that vertically passes through the reflector <NUM>-<NUM> and the reflector <NUM>-<NUM>. The reflector <NUM>-<NUM> is fastened to a fixed position in the filter module <NUM> by using the fastening structure <NUM>-<NUM>. When being driven by the high-speed moving motor <NUM>-<NUM>, the reflector <NUM>-<NUM> moves away from or toward the reflector <NUM>-<NUM> in the optical axis direction.

The reflector <NUM>-<NUM> may reflect light incident on the reflector <NUM>-<NUM> to the reflector <NUM>-<NUM>, and the reflector <NUM>-<NUM> may also reflect light incident on the reflector <NUM>-<NUM> to the reflector <NUM>-<NUM>. For example, opposite inner surfaces of the reflector <NUM>-<NUM> and the reflector <NUM>-<NUM> have high reflectivities.

Based on a principle of Fabry-Pérot (Fabry-Pérot, F-P) interference, when two reflection surfaces of the reflector <NUM>-<NUM> and the reflector <NUM>-<NUM> are strictly parallel, and monochrome light coming from any point of a light source is radiated to the reflector <NUM>-<NUM> and the reflector <NUM>-<NUM> at an incident angle θ, transmitted light is obtained through superposition of many parallel beams, and an optical path difference between any pair of adjacent beams is <NUM>×n×l×cosθ, and transmittance of the reflector <NUM>-<NUM> and the reflector <NUM>-<NUM> is determined by the optical path difference, where n refers to a refractive index of a medium between the reflector <NUM>-<NUM> and the reflector <NUM>-<NUM>, <NUM> refers to a distance between the reflector <NUM>-<NUM> and the reflector <NUM>-<NUM>, and θ refers to the incident angle.

When the optical path difference is an integer multiple of a wavelength of a target optical signal, the reflector <NUM>-<NUM> and the reflector <NUM>-<NUM> have maximum transmittance for the target optical signal. In this case, it may be considered that the filter module <NUM> can allow only the target optical signal to pass through and reflect light of another wavelength.

Therefore, the reflector <NUM>-<NUM> may be moved by using the high-speed moving motor <NUM>-<NUM>, to change the distance between the reflector <NUM>-<NUM> and the reflector <NUM>-<NUM>, so that an optical path difference of transmitted light between the reflector <NUM>-<NUM> and the reflector <NUM>-<NUM> can be adjusted, and therefore, transmittance of light that can pass through the reflector <NUM>-<NUM> and the reflector <NUM>-<NUM> can be adjusted, and the filter module <NUM> finally outputs a target optical signal of a required wavelength.

In other examples, the reflector <NUM>-<NUM> may also be disposed on the high-speed moving motor and move with the high-speed moving motor. In these examples, it only needs to be ensured that the distance between the reflector <NUM>-<NUM> and the reflector <NUM>-<NUM> can change when the reflector <NUM>-<NUM> and the reflector <NUM>-<NUM> move with the high-speed moving motor, so that the optical path difference can be an integer multiple of the wavelength of the target optical signal.

The filter module <NUM> may be continuously tunable in an entire visible light range, or may be continuously tunable in a visible light range and a near infrared light range. When the filter module <NUM> is continuously tunable in the entire visible light range, the reflectors <NUM>-<NUM> and <NUM>-<NUM> may usually be silver (Ag)-plated reflectors.

The high-speed moving motor <NUM>-<NUM> may be an MEMS or a piezo high-speed moving motor. The high-speed moving motor <NUM>-<NUM> may receive a control signal output by a filter control unit. The control signal is used to control a moving distance of the high-speed moving motor <NUM>-<NUM>.

Optionally, if infrared light is not considered for image processing, an infrared cut-off filter <NUM>-<NUM> may be added to filter the infrared light, as shown in <FIG>. The infrared cut-off filter <NUM>-<NUM> completely covers an optical aperture of the reflector <NUM>-<NUM>, so that only light of a visible light band can be allowed to pass.

The filter module <NUM> includes a linear polarizer <NUM>-<NUM>, a phase delay unit <NUM>-<NUM>, a liquid crystal cell <NUM>-<NUM>, and an analyzer <NUM>-<NUM>. The linear polarizer <NUM>-<NUM>, the phase delay unit <NUM>-<NUM>, the liquid crystal cell <NUM>-<NUM>, and the analyzer <NUM>-<NUM> are sequentially arranged in an optical axis direction. An optical axis may be understood as a center line of a light pillar (a beam) that vertically passes through the linear polarizer <NUM>-<NUM>.

An optical signal is converted into linearly polarized light by using the linear polarizer <NUM>-<NUM>, and under an action of the phase delayer <NUM>-<NUM> and the liquid crystal cell <NUM>-<NUM>, a birefringence effect occurs on the linearly polarized light, and a phase difference is generated, so that the linearly polarized light rotates in a polarization direction, and therefore only an optical signal that has a direction consistent with that of the analyzer <NUM>-<NUM> can pass. Phase differences caused by a same liquid crystal rotation direction to optical signals of different bands are different. Therefore, a variable voltage may be output to the liquid crystal cell, and the variable voltage is used to control the liquid crystal cell to select a target optical signal of a corresponding band. The liquid crystal cell <NUM>-<NUM> may receive a control signal output by a filter control unit. The control signal is used to control an input voltage of the liquid crystal cell <NUM>-<NUM>.

An infrared cut-off filter is added to the filter module <NUM> to filter out infrared light, so that imaging quality is improved. In the tunable filter module <NUM>, there is no special requirement on a position of the infrared cut-off filter, provided that the infrared cut-off filter can cover an entire optical aperture region. In an example, as shown in <FIG>, an infrared cut-off filter <NUM>-<NUM> is arranged behind the analyzer in the optical axis direction.

Optionally, as shown in <FIG>, the structure shown in <FIG> (a structure in a dashed-line box in <FIG>) is used as an integral unit, and a plurality of such structures are sequentially arranged in the optical axis direction to obtain a new filter module <NUM>. The filter structure can output an optical signal of a finer band. Optionally, an infrared cut-off filter may be added to the filter module <NUM> to filter out infrared light, so that imaging quality is improved.

In the tunable filter module <NUM>, there is no special requirement on a position of the infrared cut-off filter, provided that the infrared cut-off filter can cover an entire optical aperture region. In an example, an infrared cut-off filter <NUM>-<NUM> is arranged behind the last analyzer in the optical axis direction.

The filter module <NUM> includes a linear polarizer <NUM>-<NUM>, a phase delay unit <NUM>-<NUM>, an acousto-optic tunable filter (AOTF) <NUM>-<NUM>, and an analyzer <NUM>-<NUM>. The linear polarizer <NUM>-<NUM>, the phase delay unit <NUM>-<NUM>, the acousto-optic tunable filter (AOTF) <NUM>-<NUM>, and the analyzer <NUM>-<NUM> are sequentially arranged in an optical axis direction. An optical axis may be understood as a center line of a light pillar (a beam) that vertically passes through the linear polarizer <NUM>-<NUM>. The phase delay unit is also referred to as a phase delayer.

An incident optical signal is converted into linearly polarized light by using the linear polarizer <NUM>-<NUM>, and under an action of the phase delayer <NUM>-<NUM> and the AOTF <NUM>-<NUM>, a birefringence effect occurs on the linearly polarized light, and a phase difference is generated, so that the linearly polarized light rotates in a polarization direction, and therefore only an optical signal that has a direction consistent with that of the analyzer <NUM>-<NUM> can pass. The AOTF is driven by using a radio frequency. Phase differences caused by a same radio frequency (radio frequency, RF) signal to different wavelengths are different. Therefore, a frequency of a radio frequency signal may be changed to control the AOTF to select light of different wavelengths.

The phase delayer may be a liquid crystal phase delayer, and a material of the AOTF may be tellurium dioxide (TeO2).

To improve imaging quality, an infrared cut-off filter is added to the filter module. In the tunable filter module <NUM>, there is no special requirement on a position of the infrared cut-off filter, provided that the infrared cut-off filter can cover an entire optical aperture region. In an example, as shown in <FIG>, an infrared cut-off filter <NUM>-<NUM> is arranged behind the analyzer in the optical axis direction.

In embodiments of this application, because the filter module can output target signal light of different bands through time division, the sensor module can obtain complete monochrome images without performing an interpolation operation, so that a problem that image quality is degraded due to an interpolation operation can be avoided.

<FIG> is a schematic flowchart of an imaging method according to an embodiment of this application. The imaging method may be performed by an imaging system shown in any one of <FIG>.

The imaging method shown in <FIG> includes S2710 to S2780. It may be understood that the imaging method provided in this application may include more or less steps. For example, when an imaging system that performs the imaging method does not include a motor module or a motor control unit, the imaging method does not include S2750 or S2740.

S2710: Start an imaging application. For example, a user taps an icon of an imaging application on a mobile phone, and the mobile phone starts the imaging application.

S2720: A filter control unit outputs a control signal to a filter module, to control the filter module to output a target optical signal.

Specifically, the filter control unit controls, based on a specified spectral mode, the filter module to perform spectral screening. The spectral mode includes but is not limited to the following modes: an RGB mode, where required bands include red, green, and blue bands; an RYB mode, where required bands include red, yellow, and blue bands; an RWB mode, where required bands include red and blue bands and a full band; an RGBW mode, where required bands include red, green, and blue bands and a full band; and some other special spectral modes, where in addition to a visible light band, required bands may include a near infrared light band, for example, used for subsequent image processing, to obtain better imaging quality in an ISP through calculation. A spectral range of each band may be fine-tuned based on actual application.

A sensor module receives an optical signal, converts the optical signal into an electrical signal (namely, raw image data), and transmits the electrical signal to the ISP. In some designs, a photosensitive integration time and a period of the sensor module fit filter times and periods of various filters in the filter module. Specifically, the sensor module continuously integrates target optical signals of a specified single band, and does not detect an optical signal in a band switching process in each spectral mode. Data obtained by the sensor module by performing continuous integration on the target optical signals of the specified single band may be referred to as narrowband images.

S2730: The ISP receives the raw image data from the sensor module, and processes the raw image data. For example, the sensor module transmits a narrowband image group to the ISP, and the ISP performs processing such as preprocessing, white balance, color restoration, gamma correction, and 3D LUT correction on narrowband images in an entire color image processing pipeline (color image processing pipeline), to finally complete color-related tuning to obtain a color image.

S2740: The motor control unit outputs control information to the motor module based on information fed back by a gyroscope, so that the motor module adjusts a distance between a lens module and the sensor module under control of the control information. If the imaging system does not include the motor module or the motor control unit, this step may not be performed.

S2750: The motor control unit outputs control information to the motor module based on focusing information output by the ISP, so that the motor module adjusts the distance between the lens module and the sensor module under control of the control information. If the imaging system does not include the motor module or the motor control unit, this step may not be performed.

S2760: A display module displays the color image obtained by the ISP through processing.

S2770: Determine whether to perform photographing or video recording. For example, when the user taps a "photo" or "video" button in a user interface, it is determined to perform photographing or video recording.

S2780: If it is determined to perform photographing or video recording, a storage module saves the color image obtained by the ISP through processing; otherwise, perform S2720 again.

In this embodiment of this application, because the narrowband images received by the ISP from the sensor module are monochrome images, complete monochrome images can be obtained in the entire ISP color pipeline without a need to perform an interpolation operation (namely, demosaicing processing), so that image resolution can be effectively increased, and a moiré pattern can be avoided, thereby finally improving imaging quality.

This application further provides an imaging method. A schematic flowchart of the imaging method is shown in <FIG>. The imaging method shown in <FIG> may include S3101 to S3107.

The imaging method may be performed by an ISP. For example, the ISP processes narrowband images in a color image processing pipeline to obtain a color image. The n narrowband images may be images photographed by using a camera module that includes a filter module shown in any one of <FIG>. A narrowband image <NUM> to a narrowband image n are in a one-to-one correspondence with n bands included in a spectral mode of an imaging system to which the ISP belongs. A narrowband image i refers to image data obtained by a sensor module by continuously integrating target optical signals of an ith band in the n bands after the filter module obtains the target optical signals of the ith band. For example, when n is equal to <NUM>, the narrowband image <NUM> corresponds to a red band, and the narrowband image <NUM> corresponds to a green band, and the narrowband image <NUM> corresponds to a blue band.

S3101: Preprocess (preprocessing) the n narrowband images.

Preprocessing herein may be performing processing unrelated to a color, for example, related processing such as noise suppression or sharpening, on image data collected by the sensor module.

For example, to implement three channels (n=<NUM>), because some tunable filters actually collect more finer channels (n><NUM>) during collection, the filters may add image information corresponding to adjacent channels in a preprocessing phase, to obtain a final channel mode.

Adding the image information corresponding to the adjacent channels can cancel random noise, to improve an anti-noise capability of an obtained image. In other words, the preprocessing manner can improve a photosensitive capability of a multi-channel filter.

S3102: Perform white balance on images obtained through preprocessing.

White balance can restore a color of a photographed scene, so that colors of scenes photographed under different light sources are similar to colors of images viewed by human eyes.

If image data of three channels is obtained through preprocessing, three data matrices are usually required when white balance processing is performed. The three data matrices are in a one-to-one correspondence with the image data of the three channels. For a manner of obtaining the three data matrices, refer to the conventional technology.

If image data of at least three channels is obtained through preprocessing, at least three data matrices are usually required when white balance processing is performed. The at least three data matrices are in a one-to-one correspondence with the image data of the at least three channels. For a manner of obtaining the at least three data matrices, refer to the manner of obtaining three data matrices.

S3103: Perform, by using a color correction matrix, color restoration on images obtained through white balance.

Color correction can ensure that a color of an image can relatively accurately reproduce a scene viewed by human eyes at a photographing scene. A dimension of the color correction matrix (color correction matrix, CCM) used for color restoration may be obtained based on a quantity of image channels obtained through preprocessing and a quantity of primary colors of a display system.

For example, when image data of n channels is obtained through preprocessing, and a display system is a system with m primary colors, a corresponding CCM is an m×n matrix, where m and n are positive integers.

For example, when image data of three channels is obtained through preprocessing, and a display system is a system with three primary colors, a corresponding CCM is a <NUM>×<NUM> matrix.

For a manner of obtaining the CCM in this embodiment of this application, refer to a manner of obtaining a <NUM>×<NUM> CCM in the conventional technology.

S3104: Perform gamma correction on images obtained through color restoration.

In this embodiment of this application, if an ith image in the n narrowband images obtained through preprocessing is denoted as a matrix λi, and a matrix used for performing white balance processing on the ith image is denoted as awbi, an example mathematical expression for performing white balance, color correction, and gamma correction on the n narrowband images obtained through preprocessing is as follows: <MAT> where λi in <MAT> represents an image data matrix of an ith channel in n channels obtained through preprocessing, i is a positive integer less than or equal to n, <MAT> represents the CCM, m represents a quantity of primary colors of a display system, ()γ represents gamma processing, λj in <MAT> represents a jth primary color image data matrix in m primary color image data matrices obtained through white balance, color correction, and gamma correction, and j is a matrix less than or equal to m.

S3105: Perform 3D LUT correction on images obtained through gamma correction.

S3106: Perform post processing (post processing) on images obtained through 3D LUT correction. Post processing is similar to preprocessing, and details are not described herein again.

S3107: Display images obtained through post processing and/or store images obtained through post processing. Before the images are stored, the images may be first compressed to reduce storage space.

It may be understood that the operations shown in <FIG> are merely an example, and the imaging method provided in this application may include more or less operations, or similar operations may be performed.

This application further provides an imaging method, and the imaging method may include S2720 and S2730. Optionally, the imaging method may further include S2740. Optionally, the method may further include S2750. Optionally, the method may further include S2760 and/or S2780.

This application further provides a camera module in an imaging system shown in any one of <FIG>.

This application further provides a multi-module camera. The multi-module camera includes a plurality of camera modules, and at least one of the camera modules is a camera module in an imaging system shown in any one of <FIG>. Optionally, at least one of the camera modules may be a conventional camera module such as a camera module based on a Bayer array sensor or a Foveon (foveon) sensor. In this way, imaging quality can be improved, and binocular ranging can be jointly implemented.

A schematic flowchart of an image method when the multi-module camera includes a conventional camera module and a camera module in an imaging system shown in any one of <FIG> is shown in <FIG>. The camera module newly provided in this application is referred to as a tunable camera module.

S2810: Start an imaging application. For this step, refer to S2710.

S2820: Start the conventional camera module to perform a preview and focusing. For this step, refer to the conventional technology.

S2830: Determine whether to use the tunable camera module to perform photographing or video recording; and if yes, perform S2840; otherwise, repeatedly perform S2850.

S2840: Use the tunable camera module to perform photographing or video recording. For a specific implementation of this step, refer to S2720 to S2780 in the imaging method shown in <FIG>.

This application further provides an imaging apparatus. The imaging apparatus includes a processing module in an imaging system shown in any one of <FIG>, and may even include a storage module and/or a display module in the imaging system.

This application further provides a terminal device. The terminal device includes an imaging system shown in any one of <FIG>.

This application further provides a mode setting method. The method includes: displaying a mode selection interface, where the mode selection interface includes a plurality of mode options; determining, based on input information of a user in the mode selection interface, a mode selected by the user, where for example, a mode corresponding to an option tapped by the user is the mode selected by the user; and setting a spectral mode based on the mode selected by the user. Different spectral modes correspond to optical signals of different bands.

This application further provides a method for adjusting a spectral mode of a camera module. The method includes: receiving indication information used to indicate to set the spectral mode of the camera module; and outputting mode information of each of a plurality of spectral modes in response to the indication information, where the mode information of each spectral mode includes name information of the spectral mode.

In different spectral modes in the plurality of spectral modes, filter channels of the camera module are different. For example, the plurality of spectral modes include but are not limited to a normal mode, a high-precision mode, a dark mode, and a print mode. Generally, a user selects the normal mode by default.

In the normal mode, a tunable filter uses a same filtering policy as a conventional Bayer filter, and uses red, green, and blue channels for filtering. In the high-precision mode, the tunable filter uses at least four channels for filtering, and spectrum fineness is greater than that of the conventional Bayer filter. In the dark mode, a filter channel of the tunable filter usually includes at least one channel that is wider than that of an RGB monochrome band, for example, RYB and RWB. Optionally, the plurality of spectral modes may further include an expert mode. The expert mode is mainly used for a requirement of a more professional population. In the expert mode, the user may define a quantity of filter channels and a band of each channel.

The method may further include: receiving second information, where the second information is used to indicate to set the spectral mode of the camera module to a target spectral mode in the plurality of spectral modes; and setting the spectral mode of the camera module to the target spectral mode in response to the second information. The target spectral mode is a spectral mode selected by the user from the plurality of spectral modes.

In some designs, the mode information of the plurality of spectral modes may be output in the form of an interface. An example is shown in <FIG>. Alternatively, the mode information of the plurality of spectral modes may be output in another manner, for example, a voice play manner.

In some designs, the mode information of each spectral mode may further include information about a band or a filter channel corresponding to the spectral mode.

<FIG> is a schematic diagram of a mode setting interface according to an embodiment of this application. The interface includes the following spectral mode options: a normal mode, a high-precision mode, a dark mode, a print mode, and an expert mode. A default mode is set to the normal mode. An icon after each mode name is a selectable icon. An icon selected by a user indicates that the user sets a spectral mode to a mode corresponding to the icon. The expert mode is controlled by a dual-selective switch, and the dual-selective switch is usually in an off state.

<FIG> is a schematic diagram of a structure of an imaging apparatus according to an embodiment of this application. The imaging apparatus <NUM> includes an obtaining module <NUM> and a processing module <NUM>. The imaging apparatus <NUM> may be configured to implement any one of the foregoing imaging methods.

The obtaining module <NUM> is configured to obtain a plurality of groups of raw image data. The plurality of groups of raw image data are raw image data obtained by a camera module by performing optical-to-electrical conversion on target optical signals that are of different bands and that are collected at different times. The processing module <NUM> is configured to perform color tuning processing on the plurality of groups of raw image data to obtain a color image. Different groups of raw image data in the plurality of groups of raw image data correspond to target optical signals of different bands.

The processing module <NUM> is specifically configured to perform white balance, color restoration, gamma correction, and three-dimensional look-up processing on the plurality of groups of raw image data.

<FIG> is a schematic diagram of a structure of an imaging apparatus according to another embodiment of this application. The apparatus <NUM> includes a memory <NUM> and a processor <NUM>.

The memory <NUM> is configured to store a program. The processor <NUM> is configured to execute the program stored in the memory <NUM>. When the program stored in the memory <NUM> is executed, the processor <NUM> is configured to perform any one of the foregoing imaging methods.

<FIG> is a schematic diagram of a structure of an apparatus for adjusting a spectral mode of a camera module according to an embodiment of this application. The apparatus <NUM> includes an input module <NUM> and an output module <NUM>. Optionally, the apparatus <NUM> may further include a processing module <NUM>. The apparatus <NUM> may be configured to implement the foregoing method for adjusting a spectral mode of a camera module.

For example, the input module <NUM> is configured to receive indication information used to indicate to set the spectral mode of the camera module. The output module <NUM> is configured to output mode information of each of a plurality of spectral modes in response to the indication information. The mode information of each spectral mode includes name information of the spectral mode.

Optionally, the input module <NUM> may be further configured to receive second information. The second information is used to indicate to set the spectral mode of the camera module to a target spectral mode in the plurality of spectral modes. The processing module <NUM> is configured to set the spectral mode of the camera module to the target spectral mode in response to the second information. The target spectral mode is a spectral mode selected by a user from the plurality of spectral modes.

<FIG> is a schematic diagram of a structure of an apparatus for adjusting a spectral mode of a camera module according to an embodiment of this application. The apparatus <NUM> includes a memory <NUM> and a processor <NUM>.

The memory <NUM> is configured to store a program. The processor <NUM> is configured to execute the program stored in the memory <NUM>. When the program stored in the memory <NUM> is executed, the processor <NUM> is configured to perform the foregoing method for adjusting a spectral mode of a camera module.

A person of ordinary skill in the art may be aware that, in combination with the examples described in embodiments disclosed in this specification, units and algorithm steps can be implemented by electronic hardware or a combination of computer software and electronic hardware.

In several embodiments provided in this application, it should be understood that the disclosed system, apparatus, and method may be implemented in another manner. For example, division into the units is merely logical function division and may be other division in actual implementation. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections may be implemented through some interfaces. The indirect couplings or communication connections between the apparatuses or units may be implemented in an electrical, mechanical, or another form.

In addition, functional units in embodiments of this application may be integrated into one processing unit, or each of the units may exist alone physically, or two or more units may be integrated into one unit.

It should be understood that the processor in embodiments of this application may be a central processing unit (central processing unit, CPU), or the processor may be another genera-purpose processor, a digital signal processor (digital signal processor, DSP), an application-specific integrated circuit (application-specific integrated circuit, ASIC), a field programmable gate array (field programmable gate array, FPGA), or another programmable logic device, discrete gate or transistor logic device, discrete hardware component, or the like. The general-purpose processor may be a microprocessor, or the processor may be any conventional processor or the like.

When the functions are implemented in a form of a software functional unit and sold or used as an independent product, the functions may be stored in a computer-readable storage medium. Based on such an understanding, the technical solutions of this application essentially, or the part contributing to the conventional technology, or some of the technical solutions may be implemented in a form of a software product. The computer software product is stored in a storage medium, and includes several instructions for instructing a computer device (which may be a personal computer, a server, a network device, or the like) to perform all or some of the steps of the methods described in embodiments of this application. The foregoing storage medium includes any medium that can store program code, for example, a USB flash drive, a removable hard disk, a read-only memory (read-only memory, ROM), a random access memory (random access memory, RAM), a magnetic disk, or an optical disc.

It should be understood that "/" in this application represents "or". The term "and/or" may include three parallel solutions. For example, "A and/or B" may include: "A", "B", and "A and B". It should be understood that "A or B" in this application may include: "A", "B", and "A and B".

Claim 1:
An imaging system (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>), comprising a camera module, comprising a filter module (<NUM>, <NUM>, <NUM>, <NUM>) and a sensor module (<NUM>, <NUM>), wherein
the filter module (<NUM>, <NUM>, <NUM>) is configured to output target optical signals of different bands in optical signals incident on the filter module (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) to a same pixel on the sensor module (<NUM>, <NUM>) at different times; and
the sensor module (<NUM>, <NUM>) is configured to: convert the target optical signals incident on the sensor module (<NUM>, <NUM>) into electrical signals, and output the electrical signals;
wherein the filter module (<NUM>) comprises a movement module and a plurality of filters;
each filter is configured to output a target optical signal in optical signals incident on the filter, and bands of target optical signals output by different filters in the plurality of filters are different; and
the movement module is configured to move, at different times, different filters in the plurality of filters to target positions at which optical signals can be received;
characterized in that
the imagining system further comprises a processing module (<NUM>, <NUM>) configured to perform color tuning processing on the plurality of groups of raw image data to obtain a color image, wherein different groups of raw image data in the plurality of groups of raw image data correspond to target optical signals of different bands, and the processing module (<NUM>) is specifically configured to perform white balance, color restoration, gamma correction, and three-dimensional look-up table processing on the plurality of groups of raw image data,
and characterized in that
the filter module (<NUM>) further comprises an infrared cut-off filter, and the infrared cut-off filter is configured to filter out infrared light in the target optical signal before the target optical signal is incident on the sensor module (<NUM>, <NUM>).