CN113498237B

CN113498237B - Driving current control method and mixed light supplement control method for multispectral light supplement lamp

Info

Publication number: CN113498237B
Application number: CN202010198709.2A
Authority: CN
Inventors: 申俊飞; 田仁富; 刘刚; 曾峰; 徐鹏
Original assignee: Hangzhou Hikvision Digital Technology Co Ltd
Current assignee: Hangzhou Hikvision Digital Technology Co Ltd
Priority date: 2020-03-20
Filing date: 2020-03-20
Publication date: 2023-03-28
Anticipated expiration: 2040-03-20
Also published as: CN113498237A

Abstract

The invention provides a driving current control method and a mixed light supplement control method for a multispectral light supplement lamp. Based on the invention, the multispectral fill-in light comprises at least two light-emitting elements with incompletely overlapped spectral ranges, so that the multispectral fill-in light can generate mixed light by the synchronous light emission of the at least two light-emitting elements in response to the driving current, and the driving current corresponding to each light-emitting element in the at least two light-emitting elements can be determined by using a mixed light ratio obtained by mixed spectrum estimation of single-light-source spectrum synthesis, and the mixed light ratio is determined by taking the mixed light as a target that the mixed light meets the expected image contrast and the expected image brightness of a fill-in object and the preset comfortable interval of human eyes to the color and brightness of the mixed light, so that the drive current determined according to the mixed light ratio can enable the fill-in light effect of the mixed light generated by the multispectral light, and can better meet the demand of a fill-in light scene to which the fill-in light object belongs to.

Description

Driving current control method and mixed light supplement control method for multispectral light supplement lamp

Technical Field

The invention relates to a light supplement technology for optical imaging, in particular to a driving current control method for a multispectral light supplement lamp and a mixed light supplement control method for the multispectral light supplement lamp.

Background

In some application scenarios of optical imaging (such as monitoring scenarios), it is necessary to improve the imaging effect by supplementing light. In addition, the prior art is dedicated to improving the light supplement effect of the light supplement lamp for different scene requirements.

Disclosure of Invention

In one embodiment, there is provided a driving current control method for a multi-spectral fill-in lamp including at least two light emitting elements whose spectral ranges do not completely overlap to generate mixed light by the at least two light emitting elements in response to synchronous light emission of driving currents, and the driving current control method includes:

acquiring single light source spectrums of at least two light-emitting elements and single light source photocurrent characteristic parameters;

synthesizing the acquired single light source spectrums into a mixed spectrum, and enabling the mixed spectrum to meet a preset light supplement target parameter by optimizing the light mixing ratio of the single light source spectrums of the at least two light emitting elements in the mixed spectrum, wherein the light supplement target parameter is used for representing a preset expected image contrast and an expected image brightness of a light supplement object and a preset comfortable interval of human eyes for the color and the brightness of the mixed light;

and determining a driving current corresponding to each of the at least two light-emitting elements based on a light mixing ratio enabling the mixed spectrum to meet a preset light supplement target parameter and the acquired single light source photocurrent characteristic parameter.

Optionally, combining the acquired single light source spectra to form a mixed spectrum comprises: and weighting and superposing the spectral power of the single light source spectrum in the same wavelength range to form a mixed spectrum, wherein the mixed light proportion comprises the proportion weight of the single light source spectrum in the spectral power weighting and superposing process.

Optionally, the step of enabling the mixed spectrum to meet the preset light supplement target parameter by optimizing the light mixing ratio of the single light source spectrums of the at least two light emitting elements in the mixed spectrum includes: acquiring a supplementary lighting target parameter, wherein the supplementary lighting target parameter is determined according to a preset comfortable interval of color and brightness of mixed light of human eyes and an expected image contrast and an expected image brightness which are preset for a supplementary lighting object, and the supplementary lighting target parameter comprises an expected color temperature interval and an expected color difference interval which takes a reference chromaticity coordinate as a reference; and optimizing the light mixing ratio of the single light source spectrums of the at least two light-emitting elements in the mixed spectrum by taking the color temperature and chromaticity coordinates of the mixed spectrum to be matched with the expected color temperature interval and the expected color difference interval as targets.

Optionally, with a goal that the color temperature and chromaticity coordinates of the mixed spectrum match the desired color temperature interval and the desired color difference interval, optimizing a mixing ratio of the single light source spectra of the at least two light emitting elements in the mixed spectrum includes: in response to the ratio weight of the mixed light ratio being assigned as an initial value or being updated, determining chromaticity coordinates of a mixed spectrum formed by combining the current ratio weights; inquiring a reference chromaticity coordinate closest to the chromaticity coordinate of the mixed spectrum and a color temperature corresponding to the reference chromaticity coordinate in a pre-established parameter corresponding table; the color temperature in the parameter correspondence table comprises color temperature values of color temperature points in a reference color temperature curve, and the reference chromaticity coordinates in the parameter correspondence table comprise coordinate values of the color temperature points in the reference color temperature curve in a chromaticity coordinate system; when the inquired color temperature does not fall into the expected color temperature interval and/or the color difference between the chromaticity coordinates of the mixed spectrum and the inquired reference chromaticity coordinates does not fall into the expected color difference interval, updating the matching weight of the spectral power weighted superposition parameter; when the inquired color temperature falls into the expected color temperature interval and the color difference between the chromaticity coordinates of the mixed spectrum and the inquired reference chromaticity coordinates falls into the expected color difference interval, determining that the color temperature and the chromaticity coordinates of the mixed spectrum match the expected color temperature interval and the expected color difference interval.

Optionally, determining chromaticity coordinates of the mixed spectrum formed by combining with the current proportioning weight comprises: determining a color tristimulus value of a mixed spectrum formed by combining the current proportioning weights; normalizing the determined color tristimulus values; and converting the x value and the y value in the normalized color tristimulus values into a u value and a v value of chromaticity coordinates respectively.

Optionally, the reference chromaticity coordinates corresponding to the color temperature points in the color temperature range not higher than 5000K in the parameter correspondence table are coordinate values corresponding to the color temperature points of the black body locus in the color temperature range not higher than 5000K in the chromaticity coordinate system in the reference color temperature curve; and the reference chromaticity coordinate corresponding to the color temperature point in the color temperature range exceeding 5000K in the parameter corresponding table is a coordinate value corresponding to the color temperature point of the daylight track in the color temperature range exceeding 5000K in the chromaticity coordinate system in the reference color temperature curve.

Optionally, the method further includes the step of optimizing a light mixing ratio of the single light source spectrums of the at least two light emitting elements in the mixed spectrum to enable the mixed spectrum to meet a preset light supplement target parameter: checking and optimizing the obtained light mixing ratio by using a color rendering index expected value further included in the obtained light supplement target parameters; if the color rendering index of the mixed spectrum is not lower than the expected color rendering index value, the verification is successful; and if the color rendering index of the mixed spectrum is lower than the expected color rendering index, triggering the re-estimation of the mixed light proportion.

Optionally, the determining, by the at least two light emitting elements, a driving current corresponding to each of the at least two light emitting elements based on a light mixing ratio that enables the mixed spectrum to satisfy a preset fill-in target parameter and the acquired single light source photocurrent characteristic parameter includes: determining a driving current corresponding to the infrared light-emitting elements in a first current range and a driving current corresponding to each visible light-emitting element in a second current range based on a light mixing ratio enabling the mixed spectrum to meet a preset light supplement target parameter and the acquired single light source photocurrent characteristic parameter; wherein the first current range is greater than the second current range.

Optionally, the visible light emitting element comprises at least two, wherein: the combination of the wavelength ranges of the single light source spectra of the at least two visible light emitting elements covers a continuous wavelength band, or the wavelength ranges of the single light source spectra of the at least two visible light emitting elements do not overlap, or the wavelength range of the single light source spectrum of one of the at least two visible light emitting elements is a fraction of the wavelength range of the single light source spectra of the other visible light emitting elements.

In another embodiment, a hybrid fill-in control method for a multi-spectral fill-in lamp is provided, wherein the multi-spectral fill-in lamp is used for filling in a field of view area of a camera, the multi-spectral fill-in lamp has at least two light sources, and the hybrid fill-in control method includes:

acquiring spectral radiant power of each light source of at least two light sources;

synthesizing the obtained spectral radiation power to obtain a mixed spectrum according to a preset first light mixing ratio, and calculating chromaticity coordinates of the mixed spectrum, wherein the first light mixing ratio is used for indicating the proportion between the spectral radiation powers of at least two light sources contained in the mixed spectrum;

according to the chromaticity coordinates of the mixed spectrum obtained through calculation, a preset reference curve with the chromaticity coordinates as a first coordinate dimension and with the color temperature as a second coordinate dimension is searched for, and the color temperature of the mixed spectrum is obtained, wherein the color temperature of the mixed spectrum has the minimum chromaticity coordinate distance between the chromaticity coordinates corresponding to the color temperature of the mixed spectrum in the preset reference curve and the chromaticity coordinates of the mixed spectrum obtained through calculation; and

when detecting that the color temperature or chromaticity coordinate distance of the mixed spectrum does not fall into a reference interval determined according to the image information of the camera, adjusting the first light mixing ratio to a second light mixing ratio which is enough to enable the color temperature or chromaticity coordinate distance of the mixed spectrum to fall into the reference interval, wherein the second light mixing ratio is used for indicating the magnitude of the driving current of each light source of any light source set of the at least two light sources;

wherein, when detecting the color temperature of the mixed spectrum, the reference interval comprises a color temperature interval associated with the image information; upon detecting the chromaticity coordinate distance, the reference interval includes a chromaticity interval associated with the image information;

wherein the image information comprises one or a combination of target attributes in the image, brightness of the image and acquisition time of the image.

acquiring spectral radiant power of each light source of any light source set in at least two light sources;

synthesizing the obtained spectral radiation power to obtain a mixed spectrum according to a preset first light mixing ratio, wherein the first light mixing ratio is used for indicating the proportion between the spectral radiation powers of at least two light sources contained in the mixed spectrum;

calculating chromaticity coordinates of the mixed spectrum by using the color tristimulus values of the mixed spectrum;

obtaining an evaluation parameter of the mixed spectrum by searching a preset reference curve which takes the chromaticity coordinate as a first coordinate dimension and takes the color temperature as a second coordinate dimension according to the chromaticity coordinate of the mixed spectrum obtained by calculation, wherein when the evaluation parameter comprises color difference, the color difference of the mixed spectrum is the minimum chromaticity coordinate distance between the chromaticity coordinate value of the mixed spectrum obtained by calculation and the preset reference curve; when the evaluation parameters comprise color temperatures, the color temperatures of the mixed spectrums have the minimum chromaticity coordinate distance between chromaticity coordinates corresponding to the color temperatures of the mixed spectrums in a preset reference curve and the chromaticity coordinate values of the mixed spectrums obtained through calculation;

detecting whether an evaluation parameter of the mixed spectrum falls into a reference interval determined according to the image information collected by the camera, wherein when the evaluation parameter comprises color difference, the reference interval comprises a color difference interval related to the image information; when the evaluation parameter comprises a color temperature, the reference interval comprises a color temperature interval related to the image information; the image information comprises one or a combination of target attributes in the image, the brightness of the image and the acquisition time of the image;

when the evaluation parameter of the mixed spectrum is detected not to fall into the reference interval, the first light mixing ratio is adjusted to a second light mixing ratio which is enough to enable the evaluation parameter of the mixed spectrum to fall into the reference interval.

Optionally, when the image information acquired by the camera includes a target indicating a human face, a color temperature interval in a reference interval determined according to the image information acquired by the camera is a first color temperature interval; when the image information collected by the camera comprises a target indicating a license plate, determining a color temperature interval in a reference interval as a second color temperature interval according to the image information collected by the camera; wherein the first color temperature interval and the second color temperature interval do not overlap, and the upper limit of the color temperature of the first color temperature interval is smaller than the lower limit of the color temperature of the second color temperature interval.

Alternatively, the first color temperature zone is set to 2000K to 3000K, and the second color temperature zone is set to 4000K to 5000K.

Optionally, detecting whether the evaluation parameter of the mixed spectrum falls within a reference interval determined according to the image information collected by the camera further includes: responding to an externally input parameter interval determined according to image information collected by a camera, and determining the input parameter interval as a reference interval for detecting evaluation parameters of the mixed spectrum; or, a parameter interval adaptively associated with the image information is generated according to the image information acquired by the camera, and the parameter interval adaptively associated with the image information is determined as a reference interval for detecting the evaluation parameter of the mixed spectrum.

Optionally, synthesizing the obtained spectral radiation power to obtain a mixed spectrum according to a preset first light mixing ratio, including: and weighting and superposing the acquired spectral radiant power in the same wavelength range by taking a preset first light mixing ratio as a ratio weight to form the radiant power in the wavelength range.

Optionally, calculating chromaticity coordinates of the mixed spectrum using the color tristimulus values of the mixed spectrum, including: determining a color tristimulus value of a mixed spectrum formed by combining the first light mixing proportion; normalizing the determined color tristimulus values; and converting the x value and the y value in the normalized color tristimulus values into a u value and a v value of chromaticity coordinates respectively.

In another embodiment, a multispectral fill light is provided, comprising:

at least two light emitting elements;

a processor for performing the driving current control method as described above;

a drive circuit for providing a current output to the at least two light-emitting elements in response to the drive current determined by the processor.

Based on the above embodiment, the multispectral fill-in light can be supported to include at least two light emitting elements whose spectral ranges are not completely overlapped, so that the multispectral fill-in light can generate mixed light by the at least two light emitting elements in response to synchronous light emission of the driving current, and for the driving current corresponding to each of the at least two light emitting elements, the multispectral fill-in light can be determined by using a mixed light ratio estimated from a mixed spectrum synthesized by a single light source spectrum, and the mixed light ratio is determined with the mixed spectrum as a target to meet a desired image contrast and a desired image brightness of a fill-in light object, and a preset comfortable interval of human eyes for the color and brightness of the mixed light, so that the driving current determined according to the mixed light ratio can enable a fill-in effect of the mixed light generated by the multispectral fill-in light object, and can further fill in the demand of a fill-in light scene to which the fill-in light object belongs.

In addition, the above embodiment does not limit the spectral ranges of at least two light emitting elements included in the multispectral fill-in light, so that the multispectral fill-in light can be supported to adopt any combination of light emitting elements in spectral ranges, thereby improving the spectral freedom of fill-in light.

Drawings

The following drawings are only schematic illustrations and explanations of the present invention, and do not limit the scope of the present invention:

FIG. 1 is a schematic flow chart illustrating a driving current control method for a multi-spectral fill-in light according to an embodiment;

FIG. 2 is a graph illustrating an example of a single light source spectrum suitable for use in the driving current control method of FIG. 1;

FIGS. 3a and 3b are graphs showing examples of single light source photocurrent characteristics suitable for the driving current control method shown in FIG. 1;

FIG. 4 is a schematic flow chart illustrating an example of the driving current control method shown in FIG. 1, wherein the desired color temperature interval and the desired color difference interval are used as constraint conditions for implementing light mixing ratio optimization;

fig. 5 is a schematic flow chart of a ratio weight updating process of the light mixing ratio in the example flow shown in fig. 4;

FIGS. 6a and 6b are schematic diagrams of reference color temperature curves for providing reference for the proportioning weight update process shown in FIG. 5;

FIG. 7 is an expanded flow diagram of the example flow shown in FIG. 4 with further color rendering indices introduced as secondary constraints;

FIG. 8 is a schematic diagram of an exemplary electrical architecture of a multi-spectral fill light in another embodiment;

fig. 9 is a schematic flowchart illustrating a hybrid fill-in light control method for a multi-spectral fill-in light according to another embodiment.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and examples.

In the embodiments described below, the multi-spectral fill light includes at least two light emitting elements whose spectral ranges do not completely overlap to produce mixed light by the at least two light emitting elements in response to synchronous emission of the drive current. The single light source spectrum of at least two light-emitting elements can be regarded as a "seed light source" for the mixed light.

Accordingly, in order to enable the multispectral fill-in light lamp to provide light that enables mixed light to approach or even meet the requirements of a fill-in light scene to which a fill-in light object belongs, the following embodiments provide a driving current control method of the multispectral fill-in light lamp, which can seek a reasonable light mixing ratio of a "seed light source" in the mixed light and determine a driving current of each light emitting element according to the sought light mixing ratio.

Fig. 1 is a schematic flowchart illustrating a driving current control method of a multi-spectral fill-in light according to an embodiment. Referring to fig. 1, the driving current control method may include:

s110: acquiring single light source spectra and single light source photocurrent characteristic parameters of at least two light-emitting elements;

s120: synthesizing the acquired single light source spectrums into a mixed spectrum, and enabling the mixed spectrum to meet a preset light supplement target parameter by optimizing the light mixing ratio of the single light source spectrums of the at least two light emitting elements in the mixed spectrum, wherein the light supplement target parameter is used for representing a preset expected image contrast (related to color and brightness) and an expected image brightness of a light supplement object and a preset comfortable interval of human eyes to the color and brightness of the mixed light;

s130: and determining the driving current corresponding to each of the at least two light-emitting elements based on the light mixing ratio which enables the mixed spectrum to meet the light supplement target parameter and the acquired single light source photocurrent characteristic parameter.

Based on the above flow, the driving current control method in this embodiment supports that the multispectral fill-in light includes at least two light emitting elements whose spectral ranges are not completely overlapped, so that the multispectral fill-in light can generate mixed light by the at least two light emitting elements in response to synchronous light emission of the driving current, and for the driving current corresponding to each of the at least two light emitting elements, the driving current can be determined by using a mixed light ratio estimated from a mixed spectrum synthesized by a single light source spectrum, and the mixed light ratio is determined with a target that the mixed spectrum satisfies an expected image contrast and an expected image brightness of a fill-in object, and a preset comfortable interval of human eyes for the color and brightness of the mixed light, so that the driving current determined according to the mixed light ratio can enable a fill-in effect of the mixed light generated by the multispectral fill-in light, and can be closer to a demand of a scene to which the fill-in light object belongs.

In addition, the driving current control method in this embodiment does not limit the spectral ranges of at least two light emitting elements included in the multispectral fill-in light, so that the multispectral fill-in light can be supported to adopt a combination of light emitting elements in any spectral range, thereby improving the spectral freedom of fill-in light.

In a combined example of the light emitting elements, the at least two light emitting elements may include an infrared light emitting element and a visible light emitting element to provide mixed light including infrared light and visible light. The visible light emitting element may be one or at least two. When the number of the visible light emitting elements is at least two, the wavelength ranges of at least two visible light emitting elements are combined to cover a continuous wave band, or the wavelength ranges of at least two visible light emitting elements do not overlap, or the wavelength range of one of the at least two visible light emitting elements is a part of the wavelength ranges of other visible light emitting elements.

For the case that the light supplement object is collocated with certain colors (for example, a license plate with a blue-background white character), if only the infrared light is used for light supplement, the color feature contrast in the image obtained based on the infrared light supplementary lighting imaging is extremely low, so that the recognition obstacle of the light supplement object in the image is caused; however, if only white visible light is used for light supplement, the white visible light has strong attenuation at night when the ambient brightness is low, so that the contrast of the light supplement object in the image formed at night is insufficient, and because the white visible light has dazzling light with high brightness, the light pollution caused by the dazzling light is easy to interfere with the visual sense of people, for example, when a road is monitored, the dazzling light generated by a white light lamp affects the safe driving of a driver.

Therefore, when the at least two light-emitting elements comprise the infrared light-emitting element and the visible light-emitting element, the arrangement is carried out to obtain the preset expected image contrast and the expected image brightness of the light supplement object, so that the mixed light generated by the multispectral light supplement lamp can meet the condition that the light supplement object has the image contrast and the image brightness which are enough to be detected and identified in an image obtained by imaging the light supplement environment; through configuring a preset comfortable interval of human eyes for the color and the brightness of the mixed light, the brightness constraint can be formed for the visible light component with the designated color in the mixed light generated by the multispectral fill light lamp.

The light supplement object has enough image contrast and image brightness in the image to be detected and recognized, and may refer to that local key features (such as license plate number contour features, face features of a human face, and texture features of human tissues) of the light supplement object in the image can be detected and recognized; the luminance constraint is formed on the visible light component with the specified color in the mixed light generated by the multispectral fill-in light, so that the luminance of the visible light component with the specified color in the mixed light generated by the multispectral fill-in light is lower than the level of causing light pollution, for example, the luminance of the white visible light component in the mixed light does not exceed the tolerance of human eyes, or the luminance of the red visible light component in the mixed light is lower than the luminance level of generating red exposure.

FIG. 2 is a graph illustrating an example of a single light source spectrum suitable for use in the driving current control method shown in FIG. 1. Taking at least two Light Emitting elements of the multispectral fill-in Light include an infrared Light Emitting element and an RGB three-color visible Light Emitting element, and an LED (Light Emitting Diode) is selected as an example, in this case, the "seed Light source" may include a single Light source spectrum of the infrared Light Emitting element and the RGB three-color visible Light Emitting element.

In fig. 2, an example of a single light source spectrum that can be acquired by S110 in the process shown in fig. 1 is shown, including an exemplary single light source spectrum 200 of infrared light IR, an exemplary single light source spectrum 210 of red visible light R, an exemplary single light source spectrum 220 of green visible light G, and an exemplary single light source spectrum 230 of blue visible light B.

The peak wavelength of the infrared light IR may be in a range of 730nm to 750nm (e.g., 740 nm), the peak wavelength of the red visible light R may be in a range of 620nm to 640nm (e.g., 629 nm), the peak wavelength of the green visible light G may be in a range of 510nm to 530nm (e.g., 519 nm), and the peak wavelength of the blue visible light B may be in a range of 440nm to 460nm (e.g., 452 nm).

Fig. 3a and 3b are diagrams illustrating examples of curves of photocurrent characteristics. Still taking the example that the at least two light-emitting elements of the multispectral fill-in light include an infrared light-emitting element and an RGB three-color visible light-emitting element, the single-light-source photocurrent characteristic may be obtained by testing actual devices of the selected light-emitting elements in advance, and may be represented by a curve of luminous flux of the light-emitting elements with variation of the energization current. Fig. 3a shows an example of a parameter curve of the single-light-source photocurrent characteristic of the infrared light emitting device that can be obtained at S110 in the process shown in fig. 1, and fig. 3b shows an example of a curve of the single-light-source photocurrent characteristic of the visible light emitting device that can be obtained at S110 in the process shown in fig. 1.

When the mixed light of the infrared light and the visible light is adopted for light compensation, the infrared light can be used as the main light of the mixed light, and the visible light is used as the auxiliary mixed light. At this time, as shown in S130 in the flow illustrated in fig. 1, based on the light mixing ratio enabling the mixed spectrum to satisfy the preset light supplement target parameter and the acquired single light source photocurrent characteristic parameter, the driving current corresponding to the infrared light emitting element in the first current range and the driving current corresponding to each visible light emitting element in the second current range may be determined, where the first current range is greater than the second current range. For example, the first current range may be set to 0 to 700 milliamps (mA), and the second current range may be set to 0 to 100mA.

Thus, in fig. 3a, an exemplary variation curve 300 of the luminous flux Φ of the infrared light-emitting element in the first current I variation range of 0 to 700 milliamperes (mA) is shown.

Also, in fig. 3b, there is shown:

an exemplary change curve 310 of luminous flux phi of a visible light emitting element generating red visible light R in a second current I change range of 0 to 100 milliamperes (mA);

an exemplary change curve 320 for the luminous flux phi of the visible light emitting element generating green visible light G in a second current I change range of 0 to 100 milliamperes (mA);

an exemplary change curve 330 of the luminous flux phi of the visible-light emitting element generating the blue visible light B in the second current I variation range of 0 to 100 milliamperes (mA).

Although the above description is directed to the case where at least two light emitting elements include both an infrared light emitting element and a visible light emitting element, it is understood that the driving current control method in this embodiment does not exclude the case where the multispectral fill light includes only at least two visible light emitting elements. That is, the driving current control method can also support a multi-spectral fill-in light including only at least two visible light emitting elements.

For example, for a detection scene with a human face as a fill-in object, the multispectral fill-in light used may adopt a mixture of green visible light and white visible light, that is, the multispectral fill-in light may include a green visible light emitting element and a white visible light emitting element, or may include three light emitting elements of RGB three-color visible light to generate a combination of green visible light and white visible light by color mixing.

At this time, by configuring a desired image contrast and a desired image brightness preset by the fill-in object, the green visible light can be made to be a main light in the mixed light, so as to help to improve the image contrast enough to be detected and recognized of the face features in the image imaged by the face in the fill-in environment, and the white visible light can be made to be an auxiliary light in the mixed light, so as to improve the environment brightness through the white visible light, so that the image brightness enough to be detected and recognized of the face features in the image imaged by the face in the fill-in environment can be obtained; by configuring a preset comfortable interval of human eyes for the color and the brightness of the mixed light, the brightness of the white visible light component in the mixed light can be constrained not to exceed the tolerance of the human eyes.

For another example, for a medical scene in which human tissue is used as a light supplement object, the multispectral light supplement lamp used may adopt a mixed light of three visible lights, namely red, green and blue, that is, the multispectral light supplement lamp may include three light emitting elements of three visible lights, RGB.

At this time, by configuring the expected image contrast and the expected image brightness preset by the light supplement object, the red visible light and the green visible light can become main lights in mixed light, so as to help improve the effect that a human body prevents texture features in an image obtained by imaging in a light supplement environment from having color feature contrast enough to be detected and identified; by configuring the preset comfortable interval of human eyes for the color and brightness of the mixed light, the blue visible light can be changed into auxiliary light with relatively low luminous flux in the mixed light, so that the color modulation compensation for the human eyes can be generated for the red visible light and the green visible light.

Therefore, for the multispectral fill-in light lamp only comprising at least two visible light emitting elements, the fill-in light target parameters are also applicable. Moreover, no matter the mixed light generated by the multispectral fill-in light is formed by mixing infrared light and at least one visible light or is formed by mixing at least two visible lights, the preset expected image contrast and expected image brightness for the fill-in light object and the preset comfortable interval of the color and brightness of the mixed light by human eyes can be determined according to the image information collected by the camera, wherein the image information comprises one or a combination of the target attribute in the image, the brightness of the image and the collection time of the image.

For better understanding of the estimation process of the mixture ratio, the following description is made in detail with reference to the examples.

In the following example, the fill-in target parameter may be presented as a reference interval determined from the image information captured by the camera, and such a reference interval may be specifically set to include a desired color temperature interval and a desired color difference interval with reference to the reference chromaticity coordinates. The reference interval may be a parameter interval determined according to image information acquired by the camera and input from the outside, or may be a parameter interval adaptively associated with image information generated in real time according to image information acquired by the camera.

Fig. 4 is a schematic flow chart of an example of implementing the light mixing ratio optimization by using the desired color temperature interval and the desired color difference interval as constraint conditions in the driving current control method shown in fig. 1. Referring to fig. 4, the flow of the example driving current control method may include:

s410: acquiring the single light source spectrum and the single light source photocurrent characteristic parameter of at least two light-emitting elements.

S421: the method comprises the steps of obtaining a supplementary lighting target parameter, wherein the supplementary lighting target parameter is determined according to an expected image contrast and an expected image brightness which are preset for a supplementary lighting object, and a preset comfortable interval of colors and brightness of mixed light of human eyes, and the supplementary lighting target parameter comprises an expected color temperature interval and an expected color difference interval with reference chromaticity coordinates as a benchmark.

S422: and optimizing the light mixing ratio of the single light source spectrums of the at least two light-emitting elements in the mixed spectrum by taking the color temperature and chromaticity coordinates of the mixed spectrum to be matched with the expected color temperature interval and the expected color difference interval as targets.

The above-mentioned S421 and S422 can be regarded as an instantiation step of S120 in the flow shown in fig. 1.

S430: and determining the driving current corresponding to each of the at least two light-emitting elements based on the light mixing ratio which enables the mixed spectrum to meet the light supplement target parameter and the acquired single light source photocurrent characteristic parameter.

In the above process, S422 may add spectral radiant powers (which may be referred to as spectral powers for short) of the single light source spectra in the same wavelength range in a weighted manner to form a mixed spectrum. The light mixing proportion comprises proportion weight of a single light source spectrum in spectral power weighted superposition. And the matching weight of the mixed light ratio of the single light source spectrums of the at least two light-emitting elements in the mixed spectrum is repeatedly optimized and updated by taking the color temperature and chromaticity coordinates of the mixed spectrum to be matched with the expected color temperature interval and the expected color difference interval as targets.

The proportioning weight of the light mixing proportion can be calibrated by the electrifying current or can be expressed by the luminous flux.

Suppose that a single light source spectrum (seed light source) l containing n (n is a positive integer of 2 or more) light emitting elements in the same wavelength range _i The light source spectrum set L of (i is a positive integer of 1 or more and n or less) is expressed by the following expression (1):

also, assume a single light source spectrum l of n seed light sources _i N matching weights m in the mixed spectrum _i The light mixing ratio M (i is a positive integer of 1 to n) is represented by the following expression (2):

M＝[m ₁ …m _n ]expression (2)

The mixed spectrum is then compared with all the single light source spectra (seed light sources) l _i The spectral power distribution l in the same wavelength range can be expressed as the following expression (3):

fig. 5 is a schematic diagram of a ratio weight updating process in the example flow shown in fig. 4. Referring to fig. 5, for S422 in the instantiation process shown in fig. 4, the updating of the matching weight (light mixing ratio) M may be a loop process with unlimited times, which specifically includes:

s510: in response to the set weight of the mixture ratio being assigned as the initial set value or being updated, chromaticity coordinates of a mixture spectrum formed by combining at the current set weight are determined.

For example, S510 may first determine the color tristimulus values of the mixed spectrum formed at the current proportioning weight combination.

Wherein the color tristimulus values may include X, Y, Z in CIE (international commission on illumination) color space, and the manner of determining the color tristimulus values may be expressed as expressions (4-1), (4-2), (4-3), and (4-4) as follows:

wherein,

the function value of the CMF (color matching functions) in the CIE color space is c0 is a predetermined constant (e.g., 100).

Then, S510 may normalize the determined color tristimulus values. The way to normalize the color tristimulus values can be expressed as expression (5) as follows:

thereafter, S510 may convert the x-value and the y-value in the normalized color tristimulus values into u-value and v-value of chromaticity coordinates. The manner in which the u value and the v value of the chromaticity coordinates are converted from the x value and the y value can be expressed as expression (6) below:

wherein a1 to a7 are all preset constants, for example, a1 may be 4, a2 and a6 may be-2, a3 and a7 may be 12, a4 and a8 may be 3, and a5 may be 6.

S520: inquiring a reference chromaticity coordinate closest to the chromaticity coordinate of the mixed spectrum and a color temperature corresponding to the reference chromaticity coordinate in a pre-established parameter corresponding table; the color temperature in the parameter correspondence table comprises a color temperature value in a reference color temperature curve, and the reference chromaticity coordinates in the parameter correspondence table comprise coordinate values corresponding to the color temperature value of the reference color temperature curve in a chromaticity coordinate system.

S530: and detecting whether the inquired result is matched with the expected color temperature interval and the expected color difference interval, if the inquired color temperature falls into the expected color temperature interval and the color difference between the chromaticity coordinate of the mixed spectrum and the inquired reference chromaticity coordinate falls into the expected color difference interval, skipping to S531, otherwise skipping to S532.

S531: when the inquired color temperature falls into the expected color temperature interval and the color difference between the chromaticity coordinates of the mixed spectrum and the inquired reference chromaticity coordinates falls into the expected color difference interval, the current proportioning weight of the mixed light proportioning is determined to be enough to enable the color temperature and the chromaticity coordinates of the mixed spectrum to be matched with the expected color temperature interval and the expected color difference interval, and then the updating process of the current flow can be ended.

S532: and when the inquired color temperature does not fall into the expected color temperature interval and/or the color difference between the chromaticity coordinates of the mixed spectrum and the inquired reference chromaticity coordinates does not fall into the expected color difference interval, updating the proportioning weight of the mixed light proportioning, and returning to the step S510.

For the parameter mapping table used in the above procedure, which is queried in S520, the reference color temperature curve whose color temperature value and the coordinate value corresponding to the color temperature value in the chromaticity coordinate system may include a black body locus (also referred to as planckian curve) and a daylight locus, where:

the reference chromaticity coordinate corresponding to the color temperature point in the color temperature range not higher than 5000K in the parameter correspondence table may be a coordinate value corresponding to the color temperature point of the black body locus in the color temperature range not higher than 5000K in the chromaticity coordinate system in the reference color temperature curve;

the reference chromaticity coordinate corresponding to the color temperature point in the color temperature range exceeding 5000K in the parameter correspondence table may be a coordinate value corresponding to the color temperature point of the daylight trajectory in the reference color temperature curve in the color temperature range exceeding 5000K in the chromaticity coordinate system.

For any one color temperature T, the spectral power distribution S (λ) of the black body can satisfy the planckian formula represented by expression (7):

where c1 and c2 are constants set in advance.

Accordingly, color tristimulus values (which can be regarded as reference color tristimulus values) as expressed by expressions (8-1), (8-2), (8-3), and (8-4) can be obtained:

the λ ranges in expressions (8-1), (8-2), (8-3), and (8-4) and those of expressions (4-1), (4-2), (4-3), and (4-4) may be the same.

Thereafter, with reference to the same principle as in expressions (5) and (6), after normalization and spatial conversion of the color tristimulus values (which may be regarded as reference color tristimulus values), reference chromaticity coordinates (u and v values) of color temperature points corresponding to different color temperatures in a color temperature range of not higher than 5000K can be obtained.

For any color temperature T in a range exceeding a color temperature of 5000K, reference chromaticity coordinates (u value and v value) of a corresponding color temperature point may be determined from the daylight trajectory, referring to the following expression (9):

wherein b1 to b11 are all preset constants. For example, b1 may be-4.607 × 10 ⁹ B2 may be 2967800, b3 may be 99.11, b4 may be 0.244063, b5 may be-2.0064 × 10 ⁹ B6 may be 1901800, b7 may be 247.88, b8 may be 0.23704, b9 may be-3, b10 may be 2.87, b11 may be 0.275.

Fig. 6a and 6b are schematic diagrams of reference color temperature curves for providing reference for the proportioning weight update process shown in fig. 5.

Fig. 6a shows a spectral locus 70 in an xy coordinate system with x and y values of the color tristimulus values as coordinates, and at the same time shows a locus segment 71 of the black body locus (also called planckian curve) in a color temperature range of not more than 5000K and a locus segment 72 of the daylight locus in a color temperature range of more than 5000K within the area enclosed by the spectral locus 70. Accordingly, the x and y values of the mixed spectrum calculated by the expression (5) can be expressed as coordinate points Mix (x _ Mix, v _ Mix) located within the area surrounded by the spectrum locus 70 as shown in fig. 6 a.

Fig. 6b shows the black body locus segment 71 and the daylight locus segment 72 in chromaticity coordinates with u-value and v-value as coordinates, and the curve formed by splicing the black body locus segment 71 and the daylight locus segment 72 can be regarded as a preset reference curve with chromaticity coordinates as a first coordinate dimension and color temperature as a second coordinate dimension. Also, chromaticity coordinates (u _ mix, v _ mix) of the mixed spectrum converted by expression (6) are also shown in fig. 6 b. As shown in fig. 6b, the parameter correspondence table created in the above manner may include the correspondence relationship between the color temperature value T _ ref and the chromaticity coordinates (u _ ref, v _ ref) of each color temperature point in the black body locus segment 71 and the daylight locus segment 72, and therefore, by referring to the parameter correspondence table created in the above manner, it can be considered that the reference chromaticity coordinates (u _ ref, v _ ref) in the chromaticity coordinate system are located at the color temperature point (whose color temperature value is T _ ref) closest to the chromaticity coordinates (u _ mix, v _ mix) of the mixed spectrum in the black body locus segment 71 having a color temperature range of not higher than 5000K or the daylight locus segment 72 having a color temperature range of higher than 5000K.

The color temperature value T _ ref of the located color temperature point is the query result of the color temperature, and the distance Duv between the chromaticity coordinates (u _ mix, v _ mix) of the mixed spectrum and the reference chromaticity coordinates (u _ ref, v _ ref) of the located color temperature point is the color difference.

When setting specific range values of the desired color temperature interval and the desired color difference interval, the reference color temperature curve can also be used for reference.

For example, when the image information acquired by the camera contains a target indicating a human face, a desired color temperature interval in a reference interval determined according to the image information acquired by the camera is a first color temperature interval; when the image information collected by the camera contains a target indicating a license plate, the color temperature interval in the reference interval determined according to the image information collected by the camera is a second color temperature interval; wherein the first color temperature interval and the second color temperature interval do not overlap, and the upper limit of the color temperature of the first color temperature interval is smaller than the lower limit of the color temperature of the second color temperature interval. For example, the first color temperature zone may be set to 2000K to 3000K, and the second color temperature zone may be set to 4000K to 5000K.

Correspondingly, when the image information acquired by the camera comprises a target indicating a human face, the color difference interval can be further noted in the color difference possibly generated in the color coordinate range corresponding to the first color temperature interval; when the image information acquired by the camera includes the target indicating the license plate, the color difference interval can further note the color difference possibly generated in the color coordinate range corresponding to the second color temperature interval.

Therefore, based on the flow shown in fig. 5, the light mixing ratio can be optimized by using the color temperature and chromaticity coordinates as constraint conditions, and therefore, a light supplement effect optimized in the color temperature and chromaticity coordinates can be generated. Moreover, compared with a mode of directly calculating the color temperature by using the color tristimulus values, the processing response speed of the flow in a table look-up mode is higher.

For the initial setting value of the light mixing ratio mentioned in S510 of the flow shown in fig. 5, it may be a fixed value, and may also be a randomized value.

The updating of the ratio weight of the light mixing ratio performed in S532 in the flow shown in fig. 5 can be handled in different cases.

Specifically, a color temperature tolerance interval broader than a desired color temperature interval and a color difference tolerance interval broader than a desired color difference interval may be set, in which:

the desired color temperature interval may be regarded as being compared to a preset desired color temperature T _thres Having a minimum color temperature tolerance deviation Delta T _min The color temperature tolerance interval can be regarded as being compared with the preset ideal color temperature T _thres Having a maximum color temperature tolerance deviation Delta T _max Coarse constraint condition of color temperature;

the desired color difference interval may be considered as being compared to a preset ideal color difference D _thres With minimum color difference tolerance deviation Delta D _min The color difference tolerance interval can be regarded as being compared with the preset ideal color difference D _thres With maximum tolerance deviation of chromatic aberration Δ D _max Coarse constraint of color difference.

If the color temperature T which does not fall into the expected color temperature interval exceeds the color temperature tolerance interval, or the color difference D which does not fall into the expected color difference interval _uv When the color difference exceeds the tolerance interval, it means that the deviation of the color temperature T obtained in S530 from the expected color temperature interval is too large, or the color difference D obtained in S530 _uv And the deviation from the expected color difference interval is too large, and at the moment, the updating can be realized by randomly assigning the ratio weight of the mixed light ratio.

If the color temperature T does not fall into the expected color temperature interval, the color difference D does not fall into the expected color difference interval _uv If the color difference falls within the color difference tolerance range, it means that the color temperature T obtained in S530 does not greatly deviate from the desired color temperature range, and the color obtained in S530Difference D _uv The deviation from the expected color difference interval is not large, and at the moment, the preset ideal color temperature T can be utilized _thres And a preset ideal color difference D _thres Determining the regulation trend of the proportion weight of the mixed light proportion, and then implementing directional updating matched with the regulation trend on the proportion weight of the mixed light proportion.

Using a predetermined ideal colour temperature T _thres And a preset ideal color difference D _thres The adjusting tendency of the ratio weight of the light mixing ratio is determined and can be represented by a weighted euclidean distance opt (i) as shown in expression (10):

opt(i)＝k1·abs(T-T _thres )+k2·abs(D _uv -D _thres ) Expression (10)

Wherein, abs (T-T) _thres ) Representing S530 the resulting color temperature T as compared to a preset ideal color temperature T _thres Euclidean distance of (a), abs (D) _ur -D _thres ) The color difference D obtained in S530 _uv Compared with the preset ideal color difference D _thres K1 and k2 are preset weighting coefficients.

For a weighted euclidean distance opt (i) when the light mixing ratio has the current ratio weight:

if the weighted Euclidean distance opt (i) is reduced by updating the ratio weight of the light mixing ratio in S532, determining the ratio change trend caused by the updating of the ratio weight as the regulation trend until the color temperature T obtained in S530 falls into the expected color temperature interval and the color difference D _uv Fall into the desired color difference interval;

otherwise, the ratio variation trend of the ratio weight is changed at the next updating until the ratio variation trend which enables the weighted Euclidean distance opt (i) to be reduced is found.

Fig. 7 is an expanded flow diagram of the preferred flow shown in fig. 4, in which a color rendering index is further introduced as a secondary constraint. Referring to fig. 7, taking as an example that the fill-in light target parameter further includes a color rendering index expected value on the basis of the desired color temperature interval and the desired color difference interval, the process shown in fig. 4 may be expanded to include the following steps:

s710: a single light source spectrum and a single light source photocurrent characteristic parameter of at least two light emitting elements are obtained.

S721: the method comprises the steps of obtaining a supplementary lighting target parameter, wherein the supplementary lighting target parameter is determined according to an expected image contrast and an expected image brightness which are preset for a supplementary lighting object, and a preset comfortable interval of colors and brightness of mixed light of human eyes, and the supplementary lighting target parameter comprises an expected color temperature interval, an expected color difference interval with reference chromaticity coordinates as a benchmark, and a color rendering index expected value.

S722: and optimizing the light mixing ratio of the single light source spectrums of the at least two light-emitting elements in the mixed spectrum by taking the color temperature and chromaticity coordinates of the mixed spectrum to be matched with the expected color temperature interval and the expected color difference interval as targets.

The processing procedure of S722 may implement optimized updating of the ratio weights in a manner as shown in fig. 5.

S723: and checking the optimized light mixing ratio by using the color rendering index expected value.

If the color rendering index of the mixed spectrum is not lower than the color rendering index expected value, the verification is successful, and S730 is skipped; if the color rendering index of the mixed spectrum is lower than the desired color rendering index, the method returns to S722 to trigger the re-estimation of the mixed light ratio.

For example, the color rendering index Ra may be determined in a manner referring to expression (11) as follows:

where Pref is a reference color rendering index (e.g., the color rendering index of sunlight, which may be 100), q is a preset constant (e.g., 0.575), p is the number of standard color samples (p is a positive integer greater than 2, e.g., 8), and Δ E _i The color difference between a mixed spectrum obtained by the current matching weight of the mixed light matching and the jth standard color sample is shown, wherein j is a positive integer which is more than or equal to 1 and less than or equal to p.

The above-mentioned S721 to S723 can be regarded as an instantiation step of S120 in the flow shown in fig. 1.

S730: and determining a driving current corresponding to each of the at least two light-emitting elements based on a light mixing ratio enabling the mixed spectrum to meet a preset light supplement target parameter and the acquired single light source photocurrent characteristic parameter.

Based on the above process, the color rendering index of the supplementary lighting can be further increased as much as possible on the basis of implementing the light mixing ratio optimization with the color temperature and chromaticity coordinates as constraint conditions, so that a better supplementary lighting effect can be generated.

Fig. 8 is a schematic diagram of an exemplary electrical architecture of a multi-spectral fill light in another embodiment. Referring to fig. 8, in another embodiment, the multispectral fill light may include:

at least two light emitting elements 910-1 to 910-n (n is a positive integer of 2 or more), wherein the at least two light emitting elements 910-1 to 910-n may include an infrared light emitting element and a visible light emitting element to provide a mixed light including infrared light and visible light. The number of the visible light emitting elements may be one, or may include at least two. When the number of the visible light emitting elements is at least two, the wavelength ranges of at least two visible light emitting elements are combined to cover a continuous wave band, or the wavelength ranges of at least two visible light emitting elements do not overlap, or the wavelength range of one of the at least two visible light emitting elements is a part of the wavelength ranges of other visible light emitting elements.

A processor 920 for performing the steps of the driving current control method according to the foregoing embodiment;

a driver circuit 930 for providing a current output to the at least two light-emitting elements 910-1 to 910-n in response to the processor determined drive current.

When at least two light emitting elements 910-1 to 910-n of the multispectral fill light are replaced for different application scenes, the processor 920 can redetermine the driving current by inputting the single light source spectrum ("seed light source") and the single light source photocurrent characteristic parameters of the replaced light emitting elements, so as to ensure the fill light effect of using the new "seed light source".

As can also be seen from fig. 8, the image pickup apparatus may further have a non-transitory computer-readable storage medium 900, the non-transitory computer-readable storage medium 900 storing instructions, which when executed by the processor 920 may cause the processor to perform the steps in the driving current control method as described in the foregoing embodiments.

Fig. 9 is a schematic flowchart illustrating a hybrid fill-in light control method for a multi-spectral fill-in light according to another embodiment. Referring to fig. 9, in another embodiment, a method for controlling a multi-spectral fill-in light of a multi-spectral fill-in light having at least two light sources for filling in a field of view of a camera includes:

s910: spectral radiant power of each light source of any set of at least two light sources is obtained.

S920: and synthesizing the obtained spectral radiation power to obtain a mixed spectrum according to a preset first light mixing ratio, wherein the first light mixing ratio is used for indicating the proportion between the spectral radiation powers of at least two light sources contained in the mixed spectrum.

For example, in S920, the preset first light mixing ratio may be used as the mixing weight, and the obtained spectral radiant powers in the same wavelength range are weighted and superimposed to form the radiant power in the wavelength range. That is, the principle of synthesizing the mixed spectrum in S920 may be substantially the same as in the foregoing expression (3).

S930: and calculating chromaticity coordinates of the mixed spectrum by using the color tristimulus values of the mixed spectrum.

For example, S930 may determine color tristimulus values of the mixed spectrum formed by combining the first mixture ratios, normalize the determined color tristimulus values, and convert x and y values of the normalized color tristimulus values into u and v values of chromaticity coordinates, respectively. That is, the principle of obtaining chromaticity coordinates by calculation in S950 may be substantially the same as the above expressions (4-1), (4-2), (4-3), and (4-4).

S940: according to the chromaticity coordinates of the mixed spectrum obtained through calculation, obtaining evaluation parameters of the mixed spectrum by searching a preset reference curve with the chromaticity coordinates as a first coordinate dimension and the color temperature as a second coordinate dimension, wherein when the evaluation parameters comprise color difference, the color difference of the mixed spectrum is the minimum chromaticity coordinate distance between the chromaticity coordinate values of the mixed spectrum obtained through calculation and the preset reference curve; and when the evaluation parameters comprise the color temperature, the color temperature of the mixed spectrum has the minimum chromaticity coordinate distance between the chromaticity coordinate corresponding to the preset reference curve and the chromaticity coordinate value of the mixed spectrum obtained through calculation.

The preset reference curve may be, for example, a curve formed by splicing the black body locus segment 71 and the sunlight locus segment 72 as shown in fig. 6 b.

S960: detecting whether an evaluation parameter of the mixed spectrum falls into a reference interval determined according to the image information collected by the camera, wherein when the evaluation parameter comprises color difference, the reference interval comprises a color difference interval related to the image information; when the evaluation parameter comprises the color temperature, the reference interval comprises a color temperature interval related to the image information; and the image information includes one or a combination of an object attribute in the image, brightness of the image, and an acquisition timing of the image.

S970: when the evaluation parameter of the mixed spectrum is detected not to fall into the reference interval, the first light mixing ratio is adjusted to a second light mixing ratio which is enough to enable the evaluation parameter of the mixed spectrum to fall into the reference interval, wherein the second light mixing ratio can be used for indicating the magnitude of the driving current of each light source of any light source set of the at least two light sources.

The process from the first light mixing ratio to the second light mixing ratio can adopt the principle basically the same as the flow shown in fig. 5.

Before S960, the hybrid supplementary lighting control method may further include: and in response to an externally input parameter interval determined according to the image information collected by the camera, determining the input parameter interval as a reference interval for detecting the evaluation parameter of the mixed spectrum. Thus, mixed light control in response to an external input configuration can be achieved.

As an alternative way to respond to the external input configuration (the two ways are not mutually exclusive), before S960, the hybrid supplementary lighting control method may further include: and generating a parameter interval adaptively associated with the image information according to the image information acquired by the camera, and determining the parameter interval adaptively associated with the image information as a reference interval for detecting the evaluation parameter of the mixed spectrum. Thus, dynamic adaptive light mixing control can be realized.

It is understood that the process illustrated in fig. 9, which may also take the form of computer instructions, is stored in the non-transitory computer-readable storage medium 900 illustrated in fig. 8 and may be executed by the processor 920.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. A driving current control method for a multi-spectral fill-in lamp, the multi-spectral fill-in lamp including at least two light emitting elements whose spectral ranges do not completely overlap to generate a mixed light by the at least two light emitting elements in response to a synchronous light emission of a driving current, the driving current control method comprising:

synthesizing the acquired single light source spectrums into a mixed spectrum, and taking the color temperature and chromaticity coordinates of the mixed spectrum to match an expected color temperature interval and an expected color difference interval as targets, optimizing the light mixing ratio of the single light source spectrums of at least two light-emitting elements in the mixed spectrum to enable the mixed spectrum to meet preset light supplement target parameters, wherein the light supplement target parameters are determined according to preset expected image contrast and expected image brightness for a light supplement object and preset comfortable intervals of human eyes for the color and brightness of the mixed light, and the light supplement target parameters comprise an expected color temperature interval and an expected color difference interval with reference chromaticity coordinates as references;

determining a driving current corresponding to each of the at least two light-emitting elements based on a light mixing ratio enabling the mixed spectrum to meet a light supplement target parameter and the acquired single light source photocurrent characteristic parameter;

the method for optimizing the mixed light ratio of the single light source spectrums of the at least two light-emitting elements in the mixed spectrum by taking the color temperature and chromaticity coordinates of the mixed spectrum to be matched with the expected color temperature interval and the expected color difference interval as targets comprises the following steps of:

in response to the ratio weight of the mixed light ratio being assigned as an initial value or being updated, determining chromaticity coordinates of a mixed spectrum formed by combining the current ratio weights;

inquiring a reference chromaticity coordinate closest to the chromaticity coordinate of the mixed spectrum and a color temperature corresponding to the reference chromaticity coordinate in a pre-established parameter corresponding table; the color temperature in the parameter correspondence table comprises a color temperature value of a color temperature point in a reference color temperature curve, and the reference chromaticity coordinates in the parameter correspondence table comprise coordinate values of the color temperature point in the reference color temperature curve in a chromaticity coordinate system;

when the inquired color temperature does not fall into the expected color temperature interval and/or the color difference between the chromaticity coordinates of the mixed spectrum and the inquired reference chromaticity coordinates does not fall into the expected color difference interval, updating the proportioning weight of the spectral power weighted superposition parameter;

when the inquired color temperature falls into a desired color temperature interval and the color difference between the chromaticity coordinates of the mixed spectrum and the inquired reference chromaticity coordinates falls into a desired color difference interval, it is determined that the color temperature and chromaticity coordinates of the mixed spectrum match the desired color temperature interval and the desired color difference interval.

2. The drive current control method of claim 1, wherein combining the acquired single light source spectra into a mixed spectrum comprises:

and weighting and superposing the spectral power of the single light source spectrum in the same wavelength range to form a mixed spectrum, wherein the mixed light ratio comprises the ratio weight of the single light source spectrum in the spectral power weighting and superposition.

3. The driving current control method according to claim 1, wherein determining chromaticity coordinates at a mixed spectrum formed by combining at a current proportioning weight comprises:

determining a color tristimulus value of a mixed spectrum formed by combining the current proportioning weights;

normalizing the determined color tristimulus values;

and converting the x value and the y value in the normalized color tristimulus values into a u value and a v value of chromaticity coordinates respectively.

4. The drive current control method according to claim 1,

the reference chromaticity coordinates corresponding to the color temperature points in the color temperature range not higher than 5000K in the parameter correspondence table are coordinate values of the color temperature points of the black body locus in the color temperature range not higher than 5000K in the chromaticity coordinate system;

and the reference chromaticity coordinate corresponding to the color temperature point in the color temperature range exceeding 5000K in the parameter corresponding table is a coordinate value corresponding to the color temperature point of the daylight track in the color temperature range exceeding 5000K in the chromaticity coordinate system in the reference color temperature curve.

5. The driving current control method according to claim 1, wherein a light mixing ratio of the single light source spectra of the at least two light emitting elements in the mixed spectrum is optimized to make the mixed spectrum satisfy a preset fill light target parameter, further comprising:

checking and optimizing the obtained mixed light ratio by using a color rendering index expected value further included in the obtained light supplement target parameter; if the color rendering index of the mixed spectrum is not lower than the expected color rendering index value, the verification is successful; and if the color rendering index of the mixed spectrum is lower than the expected color rendering index, triggering the re-estimation of the mixed light proportion.

6. The method for controlling driving current according to claim 1, wherein the at least two light emitting elements include an infrared light emitting element and a visible light emitting element, and the determining the driving current corresponding to each of the at least two light emitting elements based on a light mixing ratio that enables a mixed spectrum to satisfy a preset light supplement target parameter and the acquired photocurrent characteristic parameter of the single light source comprises:

determining a driving current corresponding to the infrared light-emitting elements in a first current range and a driving current corresponding to each visible light-emitting element in a second current range based on a light mixing ratio enabling the mixed spectrum to meet a light supplement target parameter and the acquired single light source photocurrent characteristic parameter;

wherein the first current range is greater than the second current range.

7. The drive current control method according to claim 1, wherein the visible light emitting element includes at least two, wherein:

the combination of the wavelength ranges of the single light source spectra of the at least two visible light emitting elements covers a continuous band of wavelengths, or,

the wavelength ranges of the individual light source spectra of the at least two visible light emitting elements do not overlap, or,

the wavelength range of the single light source spectrum of one of the at least two visible light emitting elements is a part of the wavelength range of the single light source spectrum of the other visible light emitting elements.

8. A mixed light supplement control method for a multispectral light supplement lamp, wherein the multispectral light supplement lamp is used for supplementing light to a visual field area of a camera, the multispectral light supplement lamp is provided with at least two light sources, and the mixed light supplement control method comprises the following steps:

when detecting that the color temperature or the minimum chromaticity coordinate distance of the mixed spectrum does not fall into a reference interval determined according to the image information of the camera, adjusting the first mixed light ratio to a second mixed light ratio which is enough to enable the color temperature or the minimum chromaticity coordinate distance of the mixed spectrum to fall into the reference interval, wherein the second mixed light ratio is used for indicating the magnitude of the driving current of each light source of any light source set of at least two light sources;

wherein, in detecting the color temperature of the mixed spectrum, the reference interval comprises a color temperature interval associated with image information; upon detecting the minimum chromaticity coordinate distance, the reference interval includes a chromaticity interval associated with image information;

9. The hybrid supplementary lighting control method according to claim 8,

when the image information acquired by the camera contains a target indicating a human face, determining a color temperature interval in a reference interval according to the image information of the camera as a first color temperature interval;

when the image information collected by the camera contains a target indicating a license plate, determining a color temperature interval in a reference interval as a second color temperature interval according to the image information of the camera;

wherein the first color temperature interval and the second color temperature interval do not overlap, and the upper limit of the color temperature of the first color temperature interval is smaller than the lower limit of the color temperature of the second color temperature interval.

10. The hybrid supplementary lighting control method of claim 9, wherein the first color temperature interval is set to 2000K to 3000K, and the second color temperature interval is set to 4000K to 5000K.

11. The hybrid supplementary lighting control method according to claim 8, further comprising:

responding to an externally input parameter interval determined according to image information collected by a camera, and determining the input parameter interval as a reference interval for detecting a mixed spectrum; or,

and generating a parameter interval adaptively associated with the image information according to the image information acquired by the camera, and determining the parameter interval adaptively associated with the image information as a reference interval for detecting the mixed spectrum.

12. The method according to claim 8, wherein synthesizing the obtained spectral radiant power to obtain a mixed spectrum according to a preset first light mixing ratio comprises:

and weighting and superposing the acquired spectral radiant power in the same wavelength range to form the radiant power in the wavelength range by taking a preset first light mixing ratio as a ratio weight.

13. The method of claim 12, wherein calculating chromaticity coordinates of the mixed spectrum comprises:

determining a color tristimulus value of a mixed spectrum formed by combining the first light mixing proportion;

normalizing the determined color tristimulus values;