CN114543692B

CN114543692B - Sunscreen detector, detection device and method

Info

Publication number: CN114543692B
Application number: CN202210448267.1A
Authority: CN
Inventors: 周勇
Original assignee: Shenzhen Maidu Technology Co ltd
Current assignee: Shenzhen Maidu Technology Co ltd
Priority date: 2022-04-27
Filing date: 2022-04-27
Publication date: 2022-07-08
Anticipated expiration: 2042-04-27
Also published as: CN114543692A

Abstract

The application relates to a sunscreen cream detector, a sunscreen cream detection device and a sunscreen cream detection method. The detection device obtains a first differential image corresponding to a specific chemical product through a reference light signal on a reference light wave band corresponding to the specific chemical product and through a reference light source and an image acquisition device, and the first differential image is used for determining the thickness distribution of the specific chemical product on the designated area, so that the application condition of the chemical product is judged by providing a universal and reliable detection means for various medical dispensing, cosmetics or other chemical products suitable for human bodies by combining an optical measurement technology and an image processing technology.

Description

Sunscreen detector, detection device and method

Technical Field

The application relates to the technical field of internet, in particular to the technical field of image processing, and particularly relates to a sunscreen detector, a sunscreen detection device and a sunscreen detection method.

Background

With the development of internet technology and image processing technology, optical measurement technology is used for nondestructive or non-contact measurement and image processing technology is used for extracting useful information from the measurement, so that the method is widely applied in many aspects, and the application of combining terminal detection capability and cloud storage capability or computing capability by using the internet also appears. These products or services that combine optical measurement technology and image processing technology can be used as accessories or integrated in intelligent terminal devices such as mobile phones and hand rings, or household daily necessities such as beauty glasses or dressing glasses, or portable diagnostic instruments, so as to bring great convenience to medical diagnosis, skin care or health monitoring. Among them, for various possible purposes such as medical care, skin care, or beauty, people need to apply various medical preparations, cosmetics, or other chemicals (also called chemical compounds, chemicals, or chemical products) suitable for human body frequently. For example, to avoid damage or aging of the skin by ultraviolet rays in the sun, a sunscreen cream or similar cosmetic may be applied. These chemicals or chemical products suitable for use in the human body are often close to the human skin tone or are indistinguishable to the human eye, and generally need to be applied uniformly in order to achieve the desired medical, maintenance or protective purpose. If the application is not uniform, for example, some areas are over-applied and some areas are under-applied or even not applied, the desired effect cannot be achieved. In addition, these chemicals or chemical products suitable for human body are not suitable for long-term maintenance on human body surface, but need to be removed or cleaned after a certain time, and the residue on human body surface may cause problems such as pore blockage.

In the prior art, a universal detection means is lacked, and an optical measurement technology and an image processing technology can be combined to provide real-time reliable judgment for the actual application conditions of various medical preparations, cosmetics or other chemical products suitable for human bodies. Moreover, products or services in the prior art require customized optical devices such as light sources and optical sensors, which not only occupy additional volume but also increase manufacturing cost, thus making it difficult to conveniently popularize to smart terminal devices such as smart phones. In addition, it is considered that users often need to make up or supplement chemicals removed due to sports, and the like, and these needs generally occur when users are outdoors or outdoors, that is, unexpected external environmental factors such as sunlight and the like must be dealt with and interfere with optical measurement results.

Therefore, a sunscreen cream detector, a sunscreen cream detection device and a sunscreen cream detection method are needed, which not only can provide a universal and reliable detection means for various medical preparations, cosmetics or other chemicals suitable for human bodies by combining an optical measurement technology and an image processing technology to judge the smearing condition of the chemicals, but also have the design advantage of being convenient for expanding to intelligent terminal equipment, and can effectively resist interference caused by external environmental factors.

Disclosure of Invention

In a first aspect, an embodiment of the present application provides a detection apparatus for measuring a thickness distribution of a specific chemical product on a specified area. The detection device includes: a reference light source configured to emit a reference light signal toward the designated area in an on state and not emit the reference light signal in an off state, wherein a spectral distribution of the reference light signal is within a reference light band, the specific chemical having greater absorptivity/reflectivity for light located within the reference light band relative to light not located within the reference light band; an image acquisition device configured to acquire an image of the specified area and a spectral distribution of the image acquired by the image acquisition device includes at least the reference light band and the visible light band; one or more processors communicatively connected with the reference light source and the image acquisition device, respectively, the one or more processors configured to: the method comprises the steps of obtaining a first image of the designated area when the reference light source is in a closed state and at least one second image of the designated area when the reference light source is in an open state through the image acquisition device, carrying out differential processing on the first image and the at least one second image so as to determine a first differential image of the designated area, and determining the thickness distribution of the specific chemical product on the designated area according to the first differential image.

According to the technical scheme described in the first aspect, the reference optical signal on the reference optical waveband corresponding to the specific chemical product and the reference light source and the image acquisition device are used for obtaining the first difference image corresponding to the specific chemical product and determining the thickness distribution of the specific chemical product on the designated area, so that the optical measurement technology and the image processing technology are combined to provide a universal and reliable detection means for various medical dispensing, cosmetics or other chemical products suitable for human bodies to judge the smearing condition of the chemical product, the design advantages of being convenient to expand to intelligent terminal equipment and household daily necessities are achieved, and interference caused by external environmental factors can be effectively resisted.

According to a possible implementation manner of the technical solution of the first aspect, an embodiment of the present application further provides that performing a difference processing on the first image and the at least one second image to determine the first difference image of the designated area includes: and carrying out pixel-level subtraction operation on the at least one second image and the first image to obtain the first differential image.

According to a possible implementation manner of the technical solution of the first aspect, an embodiment of the present application further provides that the at least one second image includes a plurality of second images and the plurality of second images respectively correspond to different emission powers of the reference light source, where performing differential processing on the first image and the at least one second image to determine the first differential image of the designated area includes: and fitting the plurality of second images to obtain fitted second images, and then performing difference processing on the first image and the fitted second images to determine the first difference image of the designated area.

According to a possible implementation manner of the technical solution of the first aspect, an embodiment of the present application further provides that the at least one second image includes a plurality of second images and the plurality of second images respectively correspond to different spectral distributions of the reference light signal of the reference light source, where performing a differential process on the first image and the at least one second image to determine the first differential image of the designated area includes: and fitting the plurality of second images to obtain fitted second images, and then performing difference processing on the first image and the fitted second images to determine the first difference image of the designated area.

According to a possible implementation manner of the technical solution of the first aspect, an embodiment of the present application further provides that the one or more processors are further configured to: when the specific chemical product is not on the designated area, obtaining a third image of the designated area when the reference light source is in an off state and a fourth image of the designated area when the reference light source is in an on state by the image acquisition device, then performing differential processing on the third image and the fourth image to determine a second differential image of the designated area, and calibrating the first differential image according to the second differential image.

According to a possible implementation manner of the technical solution of the first aspect, an embodiment of the present application further provides that the detection apparatus further includes a calibration light source configured to emit a calibration light signal toward the designated area in an on state and not emit the calibration light signal in an off state, where a spectral distribution of the calibration light signal is located in a calibration light band, and the specific chemical substance has weaker absorption/reflection property on light located in the calibration light band relative to light not located in the calibration light band. Wherein the one or more processors are further configured to: obtaining a fifth image of the designated area by the image acquisition device when the calibration light source is in an on state, then performing difference processing on the first image and the fifth image to determine a third difference image of the designated area, and calibrating the first difference image according to the third difference image.

According to a possible implementation manner of the technical solution of the first aspect, an embodiment of the present application further provides that the calibration light source and the reference light source belong to the same adjustable light source.

According to a possible implementation manner of the technical solution of the first aspect, an embodiment of the present application further provides that the one or more processors are further configured to: obtaining a depth map of the designated area, and calibrating the first differential image according to the depth map.

According to a possible implementation manner of the technical solution of the first aspect, an embodiment of the present application further provides that performing a difference processing on the first image and the at least one second image to determine the first difference image of the designated area includes: respectively identifying interesting regions ROI on the first image and the at least one second image, and carrying out pixel level subtraction operation on pixel points in the ROI of the at least one second image and pixel points in the ROI of the first image to obtain the first differential image.

According to a possible implementation manner of the technical solution of the first aspect, an embodiment of the present application further provides that an exposure time for obtaining the at least one second image by the image capturing device is adjustable, and the adjustment of the exposure time is based on a dynamic range of the image capturing device and on a shooting time interval between the first image and the at least one second image.

According to a possible implementation manner of the technical solution of the first aspect, an embodiment of the present application further provides that determining, according to the first difference image, a thickness distribution of the specific chemical product on the designated area includes: calculating the intensity distribution of the reflected light signal corresponding to the reference light signal on the designated area according to the RGB intensity on the first differential image, and determining the thickness distribution of the specific chemical product on the designated area according to the intensity distribution of the reflected light signal on the designated area.

According to a possible implementation manner of the technical solution of the first aspect, an embodiment of the application further provides that the detection apparatus further includes a broadband filter attached to the image acquisition apparatus, and the broadband filter is configured such that a spectral distribution of the image acquired by the image acquisition apparatus does not include light except the reference light band, the visible light band, and the calibration light band.

According to a possible implementation manner of the technical solution of the first aspect, an embodiment of the present application further provides that the one or more processors are further configured to: obtaining a preset or user-specified preference configuration, and calibrating the first differential image according to the preference configuration.

According to a possible implementation manner of the technical solution of the first aspect, an embodiment of the present application further provides that the specific chemical product is a sunscreen cream based on a chemical sunscreen agent, the designated area is a face or a hand of a user, the reference light band is located in an ultraviolet light band, the calibration light band is located in an infrared light band, the sunscreen cream based on the chemical sunscreen agent has stronger absorptivity for light located in the ultraviolet light band relative to light not located in the ultraviolet light band, and the sunscreen cream based on the chemical sunscreen agent has weaker absorptivity for light located in the infrared light band relative to light not located in the infrared light band.

According to a possible implementation manner of the technical solution of the first aspect, the embodiment of the present application further provides that the specific chemical product is a chemical sunscreen cream and the chemical sunscreen cream has a stronger absorption property for light located in the reference optical band relative to light not located in the reference optical band, or the specific chemical product is a physical sunscreen cream and the physical sunscreen cream has a stronger reflection property for light located in the reference optical band relative to light not located in the reference optical band.

According to a possible implementation manner of the technical solution of the first aspect, an embodiment of the present application further provides that the designated area is a face or a hand of a user, and the reference light band is located in an ultraviolet light band.

According to a possible implementation manner of the technical solution of the first aspect, an embodiment of the present application further provides that the specific chemical product is a non-colorless coating film conditioner and has a dominant hue, the designated area is a coating film area, and the reference light band is located outside a band corresponding to the dominant hue.

In a second aspect, the embodiment of the application provides a sunscreen detector. The sunscreen detector comprises the detection device according to any one of the first aspect, wherein the specific chemical product is sunscreen, the designated area is the face or the hand of a user, the reference light band is located in an ultraviolet light band, and the sunscreen detector determines whether the user evenly coats the sunscreen on the designated area according to the thickness distribution of the specific chemical product on the designated area determined by the detection device.

According to the technical scheme described in the second aspect, the reference optical signal on the reference optical wave band corresponding to the specific chemical product and the first differential image corresponding to the specific chemical product are obtained through the reference light source and the image acquisition device to determine the thickness distribution of the specific chemical product on the designated area, so that the optical measurement technology and the image processing technology are combined to provide a universal and reliable detection means for various medical dispensing, cosmetics or other chemical products suitable for human bodies to judge the smearing condition of the chemical product, the design advantages of being convenient to expand to intelligent terminal equipment and household daily necessities are achieved, and the interference caused by external environmental factors can be effectively resisted.

In a third aspect, embodiments of the present application provide a detection method for measuring a thickness distribution of a specific chemical product on a specified area. The detection method comprises the following steps: providing a reference light source configured to emit a reference light signal toward the designated area in an on state and not emit the reference light signal in an off state, wherein a spectral distribution of the reference light signal is within a reference light band, the specific chemical having greater absorption/reflectivity of light located within the reference light band relative to light not located within the reference light band; providing an image acquisition device configured to acquire an image of the specified area and a spectral distribution of the image acquired by the image acquisition device includes at least the reference light band and the visible light band; obtaining, by the image acquisition device, a first image of the designated area when the reference light source is in an off state and at least one second image of the designated area when the reference light source is in an on state; and performing differential processing on the first image and the at least one second image to determine a first differential image of the designated area and determine a thickness distribution of the specific chemical product on the designated area according to the first differential image.

According to the technical scheme described in the third aspect, the reference optical signal on the reference optical waveband corresponding to the specific chemical product and the first differential image corresponding to the specific chemical product are obtained through the reference light source and the image acquisition device to be used for determining the thickness distribution of the specific chemical product on the designated area, so that the optical measurement technology and the image processing technology are combined to provide a universal and reliable detection means for various medical dispensing, cosmetics or other chemical products suitable for human bodies to judge the smearing condition of the chemical product, the design advantages of being convenient to expand to intelligent terminal equipment and household daily necessities are achieved, and interference caused by external environmental factors can be effectively resisted.

In a fourth aspect, the present application provides a non-transitory computer-readable storage medium, wherein the computer-readable storage medium stores computer instructions, and when executed by a processor, the computer instructions implement the detection method according to the third aspect.

According to the technical scheme described in the fourth aspect, the reference optical signal on the reference optical waveband corresponding to the specific chemical product and the first differential image corresponding to the specific chemical product are obtained through the reference light source and the image acquisition device to determine the thickness distribution of the specific chemical product on the designated area, so that the optical measurement technology and the image processing technology are combined to provide a universal and reliable detection means for various medical dispensing, cosmetics or other chemical products suitable for human bodies to judge the smearing condition of the chemical product, the design advantages of being convenient to expand to intelligent terminal equipment and household daily necessities are achieved, and the interference caused by external environmental factors can be effectively resisted.

Drawings

In order to explain the technical solutions in the embodiments or the background art of the present application, the drawings used in the embodiments or the background art of the present application will be explained below.

Fig. 1 shows a block diagram of a detection apparatus provided in an embodiment of the present application.

Fig. 2 shows a schematic flowchart of a detection method provided in an embodiment of the present application.

Fig. 3 shows a block diagram of an electronic device used in the detection method shown in fig. 2 according to an embodiment of the present application.

Detailed Description

In order to solve the technical problems of various defects in the prior art, the embodiment of the application provides a sunscreen detector, a sunscreen detection device and a sunscreen detection method. Wherein the detection device comprises: a reference light source configured to emit a reference light signal toward the designated area in an on state and not emit the reference light signal in an off state, wherein a spectral distribution of the reference light signal is within a reference light band, the specific chemical having greater absorptivity/reflectivity for light located within the reference light band relative to light not located within the reference light band; an image acquisition device configured to acquire an image of the specified area and a spectral distribution of the image acquired by the image acquisition device includes at least the reference light band and the visible light band; one or more processors communicatively connected with the reference light source and the image acquisition device, respectively, the one or more processors configured to: the method comprises the steps of obtaining a first image of the designated area when the reference light source is in a closed state and at least one second image of the designated area when the reference light source is in an open state through the image acquisition device, carrying out differential processing on the first image and the at least one second image so as to determine a first differential image of the designated area, and determining the thickness distribution of the specific chemical product on the designated area according to the first differential image. The embodiment of the application has the following beneficial technical effects: the system can not only combine the optical measurement technology and the image processing technology to provide a universal and reliable detection means for various medical preparations, cosmetics or other chemicals suitable for human bodies to judge the smearing condition of the chemicals, but also has the design advantage of being convenient for expanding to intelligent terminal equipment, and can effectively resist the interference caused by external environmental factors.

The embodiment of the application can be applied to the following application scenes, including but not limited to medical diagnosis, skin care, health monitoring, sun cream smearing suggestions, makeup removal condition query, function expansion of intelligent terminal equipment such as a smart phone and household daily necessities such as a beauty mirror and the like.

The embodiments of the present application may be modified and improved according to specific application environments, and are not limited herein.

In order to make the technical field of the present application better understand, embodiments of the present application will be described below with reference to the accompanying drawings in the embodiments of the present application.

Fig. 1 shows a block diagram of a detection apparatus provided in an embodiment of the present application. The inspection apparatus shown in fig. 1 is used to measure the thickness distribution of a specific chemical product over a designated area (not shown). As shown in fig. 1, the detection device includes a reference light source 102. The reference light source 102 is configured to emit a reference light signal toward the designated area in an on state and not emit the reference light signal in an off state. Wherein the spectral distribution of the reference optical signal is within a reference optical band, the specific chemical having greater absorption/reflectance of light in the reference optical band relative to light not in the reference optical band. The detection apparatus further comprises an image acquisition apparatus 104. The image capturing device 104 is configured to capture an image of the specified area and a spectral distribution of the image captured by the image capturing device 104 includes at least the reference optical band and the visible optical band. The detection apparatus also includes one or more processors. Fig. 1 illustrates a processor 110. It should be understood that the detection apparatus may include any number of processors and that these processors may have the same or different architectures, operating systems, electronic circuits, or other configurations or parameters. It should be understood that the connection and functions described herein with respect to the processor 110 can be accomplished by any number of processors included in the detection apparatus, for example, the detection apparatus can include multiple processors connected in parallel for performing the functions originally performed by the processor 110 in parallel. With continued reference to fig. 1, a processor 110 is communicatively coupled to the reference light source 102 and the image capture device 104, respectively. The processor 110 (or one or more processors included in the detection apparatus of fig. 1) is configured to: obtaining, by the image acquisition device 104, a first image of the designated area when the reference light source is in an off state and at least one second image of the designated area when the reference light source is in an on state, and performing a difference processing on the first image and the at least one second image to determine a first difference image of the designated area and determine a thickness distribution of the specific chemical product on the designated area according to the first difference image.

Referring to fig. 1, as mentioned above, the spectral distribution of the reference optical signal is located in the reference optical band, and the specific chemical has stronger absorption/reflection for the light located in the reference optical band relative to the light not located in the reference optical band. As such, when the reference light source 102 emits the reference light signal toward the designated area in the on state, this means that the image of the designated area acquired by the image acquisition device 104 when the reference light source 102 is in the on state is generated under the combined action of the reference light signal and other factors. Other factors here refer to factors other than the reference light signal emitted by the reference light source 102 that can affect the image of the specified area captured by the image capture device 104, such as ambient light, sunlight, external light sources other than with respect to the detection device, and so forth. These other factors are generally independent of the detection device or are otherwise uncontrollable and unpredictable. For example, if the detection device measures the thickness distribution of a specific chemical product (e.g., sunscreen) on a designated area (e.g., the face of a user) under outdoor conditions, the outdoor lighting conditions, including sunlight, etc., can be considered as other factors relative to the reference light signal of the reference light source 102 that can be controlled by the detection device, are unpredictable and uncontrollable. On the other hand, when the reference light source 102 does not emit the reference light signal in the off state, this means that the image of the designated area acquired by the image acquisition device 104 when the reference light source 102 is in the off state is generated by the effect of other factors. As described above, the processor 110 is configured to obtain, by the image capturing device 104, a first image of the designated area when the reference light source is in the off state and at least one second image of the designated area when the reference light source is in the on state. Here, the first image is generated by other factors or factors other than the reference light signal emitted by the reference light source 102, and the at least one second image is generated by the combined action of the reference light signal and other factors. In this way, the detection means may control the image capture means 104 to obtain the interval between the moment of obtaining the first image and the moment of obtaining the at least one second image, respectively, and to make the interval small enough so that the other factors remain substantially unchanged at the moment of obtaining the first image and the moment of obtaining the at least one second image. For example, if the image acquisition device 104 is a camera, such as a camera on a smartphone, the interval between the capturing time of the first image and the capturing time of the at least one second image may be controlled, for example, such that the interval is sufficiently small, such as less than one hundredth of a second. The current camera or the part providing the photographing function of the smart phone can achieve a shutter shooting speed of 1/125-1/500, namely 125-500 images per second can be shot. Such a shutter shooting speed is sufficient to provide a sufficiently small shooting interval or a sufficiently small distance between the moment of obtaining the first image and the moment of obtaining the at least one second image. The detection means may thus control the capturing speed or the capturing interval or the image capturing frequency of the image capturing means 104 such that other factors with respect to the reference light signal of the reference light source 102 remain substantially unchanged at the moment of obtaining the first image and at the moment of obtaining the at least one second image.

Continuing to refer to fig. 1, as described above, the processor 110 is further configured to perform a difference processing on the first image and the at least one second image to determine a first difference image of the designated area. The first differential image may be any suitable differential processing method, such as division or subtraction, as long as it can reflect the change between the first image and the at least one second image, and the change or useful information contained in the first differential image almost comes from the reference light signal emitted by the reference light source 102, because the influence of other factors with respect to the reference light signal of the reference light source 102 is eliminated by the differential processing. In other words, the first differential image represents a change between the first image generated under the action of the other factors and the at least one second image generated under the combined action of the reference light signal and the other factors, and therefore the change mainly comes from the influence of the reference light signal under the condition that the other factors are basically kept unchanged, which means that the first differential image represents the influence of the reference light signal on the image of the designated area acquired by the image acquisition device 104. As mentioned above, the spectral distribution of the reference optical signal is within a reference optical band, and the specific chemical has a stronger absorption/reflection of light located in the reference optical band relative to light not located in the reference optical band. In this way, the portion of the designated area covered by the specific chemical exhibits a stronger absorption or a stronger reflection of the reference light signal than the portion not covered by the specific chemical. The greater absorption means that the portion of the reference light signal that is illuminated by the specific chemical will reflect less light than the portion that is not covered by the specific chemical because the portion that is covered by the specific chemical will absorb more of the reference light signal and reflect less light than the portion that is not covered by the specific chemical. The stronger reflectivity means that more light is reflected from the reference light signal irradiated to the portion covered by the specific chemical product than from the portion not covered by the specific chemical product, because more reference light signal is reflected from the portion covered by the specific chemical product than from the portion not covered by the specific chemical product. In general, the thicker the thickness of the specific chemical product is, the stronger the absorption or reflection is. That is, the portion of the specific chemical product having a relatively high thickness exhibits a greater absorption or a greater reflection of the reference light signal than the portion of the specific chemical product having a relatively low thickness. In this way, by analyzing the light intensity value or the RGB intensity of the pixel point on the first differential image, or by using any suitable spectral analysis or light intensity measurement technique, the absorption or reflection intensity distribution of each part on the designated area to the reference light signal can be obtained according to the first differential image, and the thickness distribution of the specific chemical product on each part on the designated area can be further determined. And, the thickness distribution of the specific chemical product at each position on the designated area in a relative sense can be obtained at least by analyzing the first differential image, that is, it can be determined that the thickness of the specific chemical product at a certain position is higher or lower than the thickness of the specific chemical product at another position. As described above, if the thickness of the specific chemical product at the first location is higher than the thickness of the specific chemical product at the second location, the first location may exhibit a stronger absorption or reflection of the reference light signal because the specific chemical product with a higher thickness covers the first location.

Referring to fig. 1, the processor 110 of the detecting apparatus shown in fig. 1 determines the thickness distribution of the specific chemical product on the designated area according to the first differential image. Then, whether the specific chemical product is uniformly coated or not and whether a part on the designated area is not coated with the specific chemical product or not can be determined according to the thickness distribution of the specific chemical product on the designated area. It should be appreciated that the particular chemicals may be distributed over the designated area in any suitable manner, including but not limited to painting, spraying, coating, or any other manner. Also, as long as the relationship between the specific chemical product and the reference light signal is satisfied, that is, the specific chemical product has stronger absorptivity/reflectivity for light in the reference light band relative to light not in the reference light band, by providing the reference light signal in the reference light band corresponding to the specific chemical product, the detection apparatus shown in fig. 1 can conveniently obtain the first differential image corresponding to the specific chemical product through the reference light source 102 and the image capturing apparatus 104 for determining the thickness distribution of the specific chemical product on the specified area. It should be understood that the specific chemical may be a formulation, paint, dressing, coating, or the like in the context of medical diagnostics, skin care, health monitoring, or other applications. For example, the particular chemical may be a sunscreen and may be more absorptive or reflective to light in the ultraviolet light band, particularly the medium ultraviolet (also called the tanning band or UVA, wavelengths from 280 nm to 320 nm) and long ultraviolet (also called the tanning band or UVB, wavelengths from 320 nm to 400 nm) wavelengths, than light in the non-ultraviolet light band. Moreover, the detection apparatus of fig. 1 may utilize a camera or a camera of an intelligent terminal device, such as a smart phone or a tablet computer, to implement the relevant functions of the image capturing apparatus 104, and the reference light source 102 may be implemented by attaching a filter or an optical device with a filtering function to an illumination light source, such as a flash lamp, of the intelligent terminal device. The relevant functions of the processor 110 of the detection apparatus of fig. 1 may be implemented by means of software or a program or code and these software, program or code may be stored and run on the intelligent terminal device. Therefore, the detection device of fig. 1 can be conveniently expanded to the existing intelligent terminal equipment without customized optical equipment. In addition, the detection device of fig. 1 can be conveniently integrated into household daily necessities such as beauty glasses and dressing glasses, because the operation principle of the detection device does not depend on a customized optical sensor, but can be realized by using a common camera or an optical sensor with an image acquisition function. Further, since the influence of other factors with respect to the reference light signal of the reference light source 102 is eliminated by the difference processing, which means that the interference caused by external environmental factors is also eliminated, the detection apparatus of fig. 1 can effectively cope with the interference of the unexpected external environmental factors such as sunlight on the optical measurement result, and can be applied to the case where the user is outdoors or outdoors. For example, when a user may take a picture of an outdoor scene or take a picture outdoors, the user may need to make up or determine the integrity and uniformity of the makeup on the face from time to time, and the detection device of fig. 1 may provide the user with a reliable thickness distribution of the makeup on the face and suggest a corresponding suggestion because the interference caused by the outdoor lighting conditions is eliminated by the differential processing.

In a word, the detection device shown in fig. 1 obtains a first differential image corresponding to a specific chemical product through a reference light signal on a reference light waveband corresponding to the specific chemical product and through a reference light source and an image acquisition device, and is used for determining the thickness distribution of the specific chemical product on the designated area, so that the detection device combines an optical measurement technology and an image processing technology to provide a universal and reliable detection means for various medical dispensing, cosmetics or other chemical products suitable for human bodies to judge the smearing condition of the chemical product, has the design advantages of being convenient for expanding to intelligent terminal equipment and household daily necessities, and can effectively resist interference caused by external environmental factors.

The inspection apparatus shown in fig. 1 is used to measure the thickness distribution of a specific chemical product over a designated area. Therefore, the detection device shown in fig. 1 can be used to measure the thickness distribution of the sunscreen on a designated area, such as the face or the hands of a user, and determine whether the sunscreen is evenly applied or whether there is an area where the sunscreen is not applied according to the thickness distribution. Specifically, with reference to fig. 1, the embodiment of the present application provides a sunscreen detector. The sunscreen detector includes the detection device according to the above-mentioned embodiment, implementation mode, or variation thereof, wherein the specific chemical product is sunscreen, the designated area is a face or a hand of a user, the reference light band is located in an ultraviolet light band, and the sunscreen detector determines whether the user evenly coats the sunscreen on the designated area according to the thickness distribution of the specific chemical product on the designated area determined by the detection device.

In one possible embodiment, the differential processing the first image and the at least one second image to determine the first differential image of the designated area includes: and carrying out pixel-level subtraction operation on the at least one second image and the first image to obtain the first differential image. It should be understood that, in addition to the pixel-level subtraction operation, the influence of other factors with respect to the reference light signal of the reference light source 102 can be effectively eliminated by, for example, division or other suitable differential processing.

In a possible embodiment, the at least one second image comprises a plurality of second images and the plurality of second images respectively correspond to different emission powers of the reference light source, wherein the differential processing of the first image and the at least one second image to determine the first differential image of the designated area comprises: and fitting the plurality of second images to obtain fitted second images, and then performing difference processing on the first image and the fitted second images to determine the first difference image of the designated area. In this way, the plurality of second images obtained by the image capturing device 104 respectively correspond to different emission powers of the reference light source 102, which can be achieved by adjusting the emission power of the reference light source 102. Under different emission powers, the influence of the reference light signal emitted by the reference light source 102 is also different, so that the plurality of second images of the designated area obtained by the image acquisition device 104 can be used for extracting more abundant information. Specifically, the fitted second images can be obtained by fitting the plurality of second images, and the fitted second images are used for performing difference processing to obtain the first difference image, which is beneficial to better determining the thickness distribution of the specific chemical product on the designated area.

In a possible embodiment, the at least one second image includes a plurality of second images and the plurality of second images respectively correspond to different spectral distributions of the reference light signal of the reference light source, wherein the differential processing of the first image and the at least one second image to determine the first differential image of the designated area includes: and fitting the plurality of second images to obtain fitted second images, and then performing difference processing on the first image and the fitted second images to determine the first difference image of the designated area. As mentioned above, the spectral distribution of the reference optical signal is within a reference optical band, and the specific chemical has a stronger absorption/reflection of light located in the reference optical band relative to light not located in the reference optical band. The spectral distribution of the reference optical signal can be adjusted as long as it remains within the reference optical band. Under different spectral distributions of the reference light signal, the reference light signal emitted by the reference light source 102 has different effects, so that the plurality of second images of the designated area obtained by the image capturing device 104 can be used to extract more abundant information. Specifically, the fitted second images can be obtained by fitting the plurality of second images, and the fitted second images are used for performing difference processing to obtain the first difference image, which is beneficial to better determining the thickness distribution of the specific chemical product on the designated area. It should be understood that the emission power, spectral distribution, and other configurations, parameters, or optical characteristics corresponding to the reference optical signal can be adjusted as needed, and the reference optical signals under different configurations, parameters, or optical characteristics can each correspond to different second images as long as they remain within the reference optical band, which is advantageous for extracting more information for better determining the thickness distribution of the specific chemical product on the designated area.

In one possible implementation, the one or more processors, such as the processor 110 of the detection apparatus of fig. 1, are further configured to: when the specific chemical product is not on the designated area, obtaining, by the image acquisition device 104, a third image of the designated area when the reference light source 102 is in an off state and a fourth image of the designated area when the reference light source 102 is in an on state, then performing a difference process on the third image and the fourth image to determine a second difference image of the designated area, and calibrating the first difference image according to the second difference image. As mentioned above, the first differential image represents the variation between the first image generated under the action of other factors (the reference light source 102 is in the off state) and the at least one second image generated under the combined action of the reference light signal and other factors (the reference light source 102 is in the on state), so that the variation mainly comes from the influence of the reference light signal under the condition that other factors are basically unchanged, which means that the first differential image represents the influence of the reference light signal on the image of the designated area acquired by the image acquisition device 104. In practice, even if the first differential image obtained by the differential processing excludes the influence of other factors with respect to the reference light signal of the reference light source 102, there may be an interference factor of the specified area itself. For example, undulations, contours, wrinkles, irregular shapes, etc. of the designated area may interfere and affect the measurement. Therefore, when the specific chemical product is not on the designated area, the second differential image of the designated area is acquired, and the first differential image can be calibrated by using the second differential image, so that the influence of the interference factor of the designated area is reduced. Specifically, when the specific chemical product is not on the designated area, a third image of the designated area when the reference light source 102 is in an off state and a fourth image of the designated area when the reference light source 102 is in an on state are obtained by the image acquisition device 104. Here, the related functions of the image capturing device 104, that is, the third image and the fourth image, may be implemented by using a camera or a photographing function of a smart terminal device, such as a smart phone or a tablet computer. The functions of generating the second difference image from the third image and the fourth image and calibrating the first difference image from the second difference image may be implemented by means of software or a program or code and these software, program or code may be stored and run on the smart terminal device. Therefore, the existing intelligent terminal equipment can be conveniently utilized to realize the calibration of the first differential image so as to obtain a better measuring effect, and the method can also be conveniently integrated on daily household articles. Taking a specific chemical product as the sunscreen cream as an example, a user can record a second differential image when the sunscreen cream is not applied to the specified area such as the face of the user through a smart phone or a cosmetic mirror in a makeup removing state or not, and can store the recorded second differential image locally or in a cloud, so that the stored second differential image can be called conveniently to calibrate, and a better sunscreen cream application suggestion can be provided for the user.

In a possible embodiment, the detection device further comprises a calibration light source (not shown). The calibration light source is configured to emit a calibration light signal toward the designated area in an on state and not emit the calibration light signal in an off state, wherein a spectral distribution of the calibration light signal is within a calibration light band, and the specific chemical has a weaker absorption/reflection of light in the calibration light band relative to light not in the calibration light band. Wherein the one or more processors, such as processor 110 of the detection apparatus of FIG. 1, are further configured to: obtaining a fifth image of the designated area with the calibration light source in an on state by the image acquisition device 104, then performing a difference processing on the first image and the fifth image to determine a third difference image of the designated area, and calibrating the first difference image according to the third difference image. As mentioned above, the spectral distribution of the reference optical signal is within a reference optical band, and the specific chemical has a stronger absorption/reflection of light located in the reference optical band relative to light not located in the reference optical band. And the first differential image represents the effect of the reference light signal on the image of the designated area captured by the image capture device 104. Here, by providing a calibration light source different from the reference light source 102 (which may be the same tunable light source as the reference light source 102 or may be provided separately from it) and obtaining a third difference image, the third difference image embodies the influence of the calibration light signal on the image of the specified area acquired by the image acquisition device 104. Because the calibration optical signal is in the calibration optical band and the particular chemical has a weaker absorption/reflection of light in the calibration optical band relative to light not in the calibration optical band, the portion of the particular chemical having a higher thickness exhibits a weaker absorption or a weaker reflection of the calibration optical signal than the portion of the particular chemical having a lower thickness. In this way, the third differential image can be used to analytically determine the intensity distribution of the absorption or reflection of the calibration light signal at each location on the designated area, and can be used to calibrate the first differential image to better determine the thickness distribution of the specific chemical product on the designated area. In some embodiments, the calibration light source and the reference light source belong to the same tunable light source. In other embodiments, the calibration light source is separately provided. In some embodiments, the detection device further comprises a broadband filter (not shown) attached to the image capture device 104, the broadband filter being such that the spectral distribution of the image captured by the image capture device 104 does not include light other than the reference light band, the visible light band, and the calibration light band. In some embodiments, the particular chemical is a chemical sunscreen-based sunscreen, the designated area is a user's face or hand, the reference band of light is in the ultraviolet band, the calibration band of light is in the infrared band, the chemical sunscreen-based sunscreen is more absorptive of light in the ultraviolet band relative to light not in the ultraviolet band, and the chemical sunscreen-based sunscreen is less absorptive of light in the infrared band relative to light not in the infrared band.

In one possible implementation, the one or more processors are further configured to: obtaining a depth map of the designated area, and calibrating the first differential image according to the depth map. Three-dimensional modeling of a depth map or a specified region can be used to analyze possible interfering factors of the specified region itself, such as undulations, contours, folds, or irregular shapes of the specified region. Calibrating the first differential image from the depth map to better determine a thickness distribution of the particular chemical over the specified area.

In one possible embodiment, the differential processing the first image and the at least one second image to determine the first differential image of the designated area includes: respectively identifying regions of Interest (ROI) on the first image and the at least one second image, and performing pixel level subtraction operation on pixel points in the ROI of the at least one second image and pixel points in the ROI of the first image to obtain the first differential image. Therefore, the pixel-level subtraction operation is limited in the ROI, so that the algorithm complexity can be reduced and the operation efficiency can be improved.

In a possible embodiment, the exposure time for obtaining the at least one second image by the image capturing device 104 is adjustable, and the adjustment of the exposure time is based on the dynamic range of the image capturing device 104 and on the capturing time interval between the first image and the at least one second image. Thus, the dynamic range of the image capturing device 104, such as a camera, can be fully utilized by adjusting the exposure time, which may result in too saturated dynamic range if the exposure time is too long, and may result in too weak signal and too high signal-to-noise ratio if the exposure time is too short. Thus improving the signal-to-noise ratio.

In one possible embodiment, determining the thickness distribution of the specific chemical product on the designated area according to the first differential image comprises: calculating the intensity distribution of the reflected light signal corresponding to the reference light signal on the designated area according to the RGB intensity on the first differential image, and determining the thickness distribution of the specific chemical product on the designated area according to the intensity distribution of the reflected light signal on the designated area. In this way, by analyzing the light intensity value or the RGB intensity of the pixel point on the first differential image, or by using any suitable spectral analysis or light intensity measurement technique, the absorption or reflection intensity distribution of each part on the designated area to the reference light signal can be obtained according to the first differential image, and the thickness distribution of the specific chemical product on each part on the designated area can be further determined.

In one possible implementation, the one or more processors are further configured to: obtaining a preset or user-specified preference configuration, and calibrating the first differential image according to the preference configuration. The preference configuration may be fine-tuned according to the specificity such as sensitivity of the designated area such as performing special treatment such as increasing or decreasing the relevant weight to the individual part, or may be set by the user himself. Taking a specific chemical product as the sunscreen cream as an example, the first differential image is used for determining the thickness distribution of the sunscreen cream applied on the face of the user and can be used for providing an application suggestion of the sunscreen cream. The preference profile may be fine-tuned based on the sensitivity or sweating level of individual parts on the user's face. For example, the nose portion is prone to sweat, and it is considered that the sunscreen on the nose portion needs to be thickened to cope with the sunscreen which may be lost due to sweat, so that the weight can be finely adjusted, for example, reduced to appear a little less than the actual thickness when the thickness distribution of the sunscreen on the nose is estimated, thus potentially encouraging the user to prefer to replenish the sunscreen on the nose portion. For another example, the user configuration may be that the user makes fine adjustments in advance according to the sensitive parts of the user or the parts to be protected.

In a possible embodiment, the specific chemical substance is a chemical sunscreen-based sunscreen having a greater absorption of light lying in the reference optical band relative to light not lying in the reference optical band, or the specific chemical substance is a physical sunscreen-based sunscreen having a greater reflection of light lying in the reference optical band relative to light not lying in the reference optical band. In some embodiments, the designated area is a user's face or hand, and the reference light band is located within an ultraviolet light band.

In one possible embodiment, the specific chemical product is a non-colorless coating formulation and has a keytone, the specified area is a coating area, and the reference light band is located outside a band corresponding to the keytone. Thus, the detection device of fig. 1 can be used to judge the thickness distribution of the non-colorless coating agent on the coating area and give corresponding suggestions.

In a possible embodiment, the specific chemical product is a sunscreen, the designated area is a face or a hand of a user, the reference light band is located in an ultraviolet light band, and the sunscreen detector determines whether the user evenly coats the sunscreen on the designated area according to the thickness distribution of the specific chemical product on the designated area determined by the detection device.

Fig. 2 shows a schematic flow chart of a detection method provided in an embodiment of the present application. The inspection method of fig. 2 is used to measure the thickness distribution of a particular chemical across a specified area. As shown in fig. 2, the detection method includes the following steps.

Step S202: a reference light source is provided.

Wherein the reference light source is configured to emit a reference light signal toward the designated area in an on state and not emit the reference light signal in an off state, wherein a spectral distribution of the reference light signal is within a reference light band, and the specific chemical has greater absorptivity/reflectivity for light located in the reference light band relative to light not located in the reference light band.

Step S204: an image capture device is provided.

Wherein the image acquisition device is configured to acquire an image of the specified area and a spectral distribution of the image acquired by the image acquisition device includes at least the reference light band and the visible light band.

Step S206: obtaining, by the image acquisition device, a first image of the designated area when the reference light source is in an off state and at least one second image of the designated area when the reference light source is in an on state.

Step S208: and performing differential processing on the first image and the at least one second image to determine a first differential image of the designated area and determine a thickness distribution of the specific chemical product on the designated area according to the first differential image.

According to the detection method shown in fig. 2, the reference light signal on the reference light wave band corresponding to the specific chemical product and the reference light source and the image acquisition device are used for obtaining the first difference image corresponding to the specific chemical product to determine the thickness distribution of the specific chemical product on the designated area, so that the optical measurement technology and the image processing technology are combined to provide a universal and reliable detection means for various medical dispensing, cosmetics or other chemical products suitable for human bodies to judge the smearing condition of the chemical product, and the detection method has the advantages of being convenient for expanding to intelligent terminal equipment and household daily necessities, and being capable of effectively resisting interference caused by external environmental factors.

It is to be understood that the above-described method may be implemented by a corresponding execution body or carrier. In some exemplary embodiments, a non-transitory computer readable storage medium stores computer instructions that, when executed by a processor, implement the above-described method and any of the above-described embodiments, implementations, or combinations thereof. In some example embodiments, an electronic device includes: a processor; a memory for storing processor-executable instructions; wherein the processor executes the executable instructions to implement the method described above and any of the embodiments, implementations, or combinations thereof described above.

Fig. 3 shows a block diagram of an electronic device used in the detection method shown in fig. 2 according to an embodiment of the present application. As shown in fig. 3, the electronic device includes a main processor 302, an internal bus 304, a network interface 306, a main memory 308, and secondary processor 310 and secondary memory 312, as well as a secondary processor 320 and secondary memory 322. The main processor 302 is connected to the main memory 308, and the main memory 308 may be used to store computer instructions executable by the main processor 302, so that the detection method shown in fig. 2 may be implemented, including some or all of the steps, and any possible combination or combination and possible replacement or variation of the steps. The network interface 306 is used to provide network connectivity and to transmit and receive data over a network. The internal bus 304 is used to provide internal data interaction between the main processor 302, the network interface 306, the auxiliary processor 310, and the auxiliary processor 320. The secondary processor 310 is coupled to the secondary memory 312 and provides secondary computing power, and the secondary processor 320 is coupled to the secondary memory 322 and provides secondary computing power. The auxiliary processors 310 and 320 may provide the same or different auxiliary computing capabilities including, but not limited to, computing capabilities optimized for particular computing needs such as parallel processing capabilities or tensor computing capabilities, computing capabilities optimized for particular algorithms or logic structures such as iterative computing capabilities or graph computing capabilities, or the like. The secondary processor 310 and the secondary processor 320 may include one or more processors of a particular type, such as a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), or the like, so that customized functions and structures may be provided. In some exemplary embodiments, the electronic device may not include an auxiliary processor, may include only one auxiliary processor, and may include any number of auxiliary processors and each have a corresponding customized function and structure, which are not specifically limited herein. The architecture of the two auxiliary processors shown in FIG. 3 is for illustration only and should not be construed as limiting. In addition, the main processor 302 may include a single-core or multi-core computing unit for providing the functions and operations necessary for the embodiments of the present application. In addition, the main processor 302 and the auxiliary processors (such as the auxiliary processor 310 and the auxiliary processor 320 in fig. 3) may have different architectures, that is, the electronic device may be a heterogeneous architecture based system, for example, the main processor 302 may be a general-purpose processor based on an instruction set operating system, such as a CPU, and the auxiliary processor may be a graphics processor GPU suitable for parallelized computation or a dedicated accelerator suitable for neural network model-related operations. The auxiliary memory (e.g., auxiliary memory 312 and auxiliary memory 322 shown in fig. 3) may be used to implement customized functions and structures with the respective auxiliary processors. While main memory 308 is operative to store the necessary instructions, software, configurations, data, etc. to provide the functionality and operations necessary for embodiments of the subject application in conjunction with main processor 302. In some exemplary embodiments, the electronic device may not include the auxiliary memory, may include only one auxiliary memory, and may further include any number of auxiliary memories, which is not specifically limited herein. The architecture of the two auxiliary memories shown in fig. 3 is illustrative only and should not be construed as limiting. Main memory 308, and possibly secondary memory, may include one or more of the following features: volatile, nonvolatile, dynamic, static, readable/writable, read-only, random-access, sequential-access, location-addressability, file-addressability, and content-addressability, and may include random-access memory (RAM), flash memory, read-only memory (ROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, a hard disk, a removable disk, a recordable and/or rewriteable Compact Disc (CD), a Digital Versatile Disc (DVD), a mass storage media device, or any other form of suitable storage media. The internal bus 304 may include any of a variety of different bus structures or combinations of different bus structures, such as a memory bus or memory controller, a peripheral bus, a universal serial bus, and/or a processor or local bus that utilizes any of a variety of bus architectures. It should be understood that the electronic device shown in fig. 3, the illustrated structure of which does not constitute a specific limitation as to the apparatus or system, may in some exemplary embodiments include more or less components than the specific embodiments and figures, or combine certain components, or split certain components, or have a different arrangement of components.

The embodiments provided herein may be implemented in any one or combination of hardware, software, firmware, or solid state logic circuitry, and may be implemented in connection with signal processing, control, and/or application specific circuitry. Particular embodiments of the present application provide an apparatus or device that may include one or more processors (e.g., microprocessors, controllers, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), etc.) that process various computer-executable instructions to control the operation of the apparatus or device. Particular embodiments of the present application provide an apparatus or device that can include a system bus or data transfer system that couples the various components together. A system bus can include any of a variety of different bus structures or combination of different bus structures, such as a memory bus or memory controller, a peripheral bus, a universal serial bus, and/or a processor or local bus that utilizes any of a variety of bus architectures. The devices or apparatuses provided in the embodiments of the present application may be provided separately, or may be part of a system, or may be part of other devices or apparatuses.

Particular embodiments provided herein may include or be combined with computer-readable storage media, such as one or more storage devices capable of providing non-transitory data storage. The computer-readable storage medium/storage device may be configured to store data, programmers and/or instructions that, when executed by a processor of an apparatus or device provided by embodiments of the present application, cause the apparatus or device to perform operations associated therewith. The computer-readable storage medium/storage device may include one or more of the following features: volatile, non-volatile, dynamic, static, read/write, read-only, random access, sequential access, location addressability, file addressability, and content addressability. In one or more exemplary embodiments, the computer-readable storage medium/storage device may be integrated into a device or apparatus provided in the embodiments of the present application or belong to a common system. The computer-readable storage medium/memory device may include optical, semiconductor, and/or magnetic memory devices, etc., and may also include Random Access Memory (RAM), flash memory, read-only memory (ROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, a hard disk, a removable disk, a recordable and/or rewriteable Compact Disc (CD), a Digital Versatile Disc (DVD), a mass storage media device, or any other form of suitable storage media.

The above is an implementation manner of the embodiments of the present application, and it should be noted that the steps in the method described in the embodiments of the present application may be sequentially adjusted, combined, and deleted according to actual needs. In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and for parts that are not described in detail in a certain embodiment, reference may be made to related descriptions of other embodiments. It is to be understood that the embodiments of the present application and the structures shown in the drawings are not to be construed as particularly limiting the devices or systems concerned. In other embodiments of the present application, an apparatus or system may include more or fewer components than the specific embodiments and figures, or may combine certain components, or may separate certain components, or may have a different arrangement of components. Those skilled in the art will understand that various modifications and changes may be made in the arrangement, operation, and details of the methods and apparatus described in the specific embodiments without departing from the spirit and scope of the embodiments herein; without departing from the principles of embodiments of the present application, several improvements and modifications may be made, and such improvements and modifications are also considered to be within the scope of the present application.

Claims

1. A sensing device for measuring a thickness distribution of a particular chemical over a specified area, the sensing device comprising:

a reference light source configured to emit a reference light signal toward the specified area in an on state and not emit the reference light signal in an off state, wherein a spectral distribution of the reference light signal is within a reference optical band, the specific chemical having greater absorptivity/reflectivity for light located in the reference optical band relative to light not located in the reference optical band;

a calibration light source configured to emit a calibration light signal toward the designated area in an on state and not emit the calibration light signal in an off state, wherein a spectral distribution of the calibration light signal is within a calibration light band, the specific chemical having a weaker absorbance/reflectance of light located in the calibration light band relative to light not located in the calibration light band;

an image acquisition device configured to acquire an image of the specified area and a spectral distribution of the image acquired by the image acquisition device includes at least the reference light band and the visible light band; one or more processors communicatively connected with the reference light source and the image acquisition device, respectively, the one or more processors configured to:

obtaining, by the image acquisition device, a first image of the designated area with the reference light source in an off state and at least one second image of the designated area with the reference light source in an on state, and

the first image and the at least one second image are subjected to differential processing to determine a first differential image of the designated area, a fifth image of the designated area in a state that the calibration light source is turned on is obtained through the image acquisition device, then the first image and the fifth image are subjected to differential processing to determine a third differential image of the designated area, the first differential image is calibrated according to the third differential image, and the thickness distribution of the specific chemical product on the designated area is determined according to the first differential image.

2. The detection apparatus of claim 1, wherein performing a difference process on the first image and the at least one second image to determine the first difference image of the designated area comprises: and carrying out pixel-level subtraction operation on the at least one second image and the first image to obtain the first differential image.

3. The detection apparatus according to claim 1, wherein the at least one second image comprises a plurality of second images and the plurality of second images respectively correspond to different emission powers of the reference light source, wherein the differential processing of the first image and the at least one second image to determine the first differential image of the designated area comprises: and fitting the plurality of second images to obtain fitted second images, and then performing difference processing on the first image and the fitted second images to determine the first difference image of the designated area.

4. The detection apparatus according to claim 1, wherein the at least one second image comprises a plurality of second images and the plurality of second images respectively correspond to different spectral distributions of the reference light signal of the reference light source, wherein the differential processing of the first image and the at least one second image to determine the first differential image of the designated area comprises: and fitting the plurality of second images to obtain fitted second images, and then performing difference processing on the first image and the fitted second images to determine the first difference image of the designated area.

5. The detection apparatus of claim 1, wherein the one or more processors are further configured to: when the specific chemical product is not on the designated area, obtaining a third image of the designated area when the reference light source is in an off state and a fourth image of the designated area when the reference light source is in an on state through the image acquisition device, then carrying out differential processing on the third image and the fourth image so as to determine a second differential image of the designated area, and calibrating the first differential image according to the second differential image.

6. The detection apparatus according to claim 1, wherein the calibration light source and the reference light source belong to the same adjustable light source.

7. The detection device of claim 1, wherein the one or more processors are further configured to: obtaining a depth map of the designated area, and calibrating the first differential image according to the depth map.

8. The detection apparatus of claim 1, wherein performing a difference process on the first image and the at least one second image to determine the first difference image of the designated area comprises: respectively identifying interesting regions ROI on the first image and the at least one second image, and carrying out pixel level subtraction operation on pixel points in the ROI of the at least one second image and pixel points in the ROI of the first image to obtain the first differential image.

9. The detection device according to claim 1, wherein an exposure time for obtaining the at least one second image by the image capturing device is adjustable and is adjusted based on a dynamic range of the image capturing device and based on a capturing time interval between the first image and the at least one second image.

10. The apparatus according to claim 1, wherein determining the thickness distribution of the specific chemical product over the designated area according to the first differential image comprises: calculating the intensity distribution of the reflected light signal corresponding to the reference light signal on the designated area according to the RGB intensity on the first differential image, and determining the thickness distribution of the specific chemical product on the designated area according to the intensity distribution of the reflected light signal on the designated area.

11. The detection device of claim 1, further comprising a broadband filter attached to the image capture device, the broadband filter being such that a spectral distribution of the image captured by the image capture device does not include light other than the reference band of light, the visible band of light, and the calibration band of light.

12. The detection apparatus of claim 1, wherein the one or more processors are further configured to: obtaining a preset or user-specified preference configuration, and calibrating the first differential image according to the preference configuration.

13. The detection apparatus according to claim 1, wherein the specific chemical product is a chemical sunscreen, the designated area is a face or a hand of a user, the reference light band is located in an ultraviolet light band, the calibration light band is located in an infrared light band, the chemical sunscreen has a stronger absorption for light located in the ultraviolet light band relative to light not located in the ultraviolet light band, and the chemical sunscreen has a weaker absorption for light located in the infrared light band relative to light not located in the infrared light band.

14. The detection apparatus according to any one of claims 1 to 12, wherein the specific chemical substance is a chemical sunscreen-based sunscreen having a stronger absorption of light located in the reference optical band relative to light not located in the reference optical band, or wherein the specific chemical substance is a physical sunscreen-based sunscreen having a stronger reflection of light located in the reference optical band relative to light not located in the reference optical band.

15. The detection apparatus as claimed in claim 14, wherein the designated area is a face or a hand of the user, and the reference light band is located in an ultraviolet light band.

16. The detecting device according to any one of claims 1 to 12, wherein the specific chemical is a non-colorless coating agent and has a keytone, the specified area is a coating area, and the reference light band is located outside a band corresponding to the keytone.

17. A sunscreen detector comprising the detection device according to any one of claims 1 to 12, wherein the specific chemical product is sunscreen, the designated area is a face or a hand of a user, the reference light band is located in an ultraviolet light band, and the sunscreen detector determines whether the user evenly coats the sunscreen on the designated area according to the thickness distribution of the specific chemical product on the designated area determined by the detection device.

18. An inspection method for measuring a thickness distribution of a specific chemical product over a specified area, the inspection method comprising:

providing a reference light source configured to emit a reference light signal toward the designated area in an on state and not emit the reference light signal in an off state, wherein a spectral distribution of the reference light signal is within a reference light band, the specific chemical having greater absorption/reflectivity of light located within the reference light band relative to light not located within the reference light band;

providing a calibration light source configured to emit a calibration light signal toward the designated area in an on state and not emit the calibration light signal in an off state, wherein a spectral distribution of the calibration light signal is within a calibration light band, the specific chemical having a weaker absorbance/reflectance of light located in the calibration light band relative to light not located in the calibration light band;

providing an image acquisition device configured to acquire an image of the specified area and a spectral distribution of the image acquired by the image acquisition device includes at least the reference light band and the visible light band;

obtaining, by the image acquisition device, a first image of the designated area when the reference light source is in an off state and at least one second image of the designated area when the reference light source is in an on state;

19. A non-transitory computer readable storage medium storing computer instructions which, when executed by a processor, implement the detection method of claim 18.