Method for adjusting UV luminosity and cosmetic mirror

Abstract

The invention provides a method for adjusting UV (ultraviolet) luminosity in a cosmetic mirror and the cosmetic mirror. The method integrates at least one camera to capture a face image of a user and a UV index sensor to obtain environmental UV index information. Through a face identification technology, two feature points of a left face and a right face in a face image are configured with a first coordinate and a second coordinate respectively, and then a first distance between the two coordinates is calculated. Calculating an included angle between the camera and the two feature points according to the first distance, the image width of the face image and the horizontal view field angle; furthermore, a trigonometric function is utilized to calculate a second distance from the camera to the two feature points according to the included angle and the first distance, and then the luminosity of the UV light provided by the UV light supplement lamp is adjusted by comparing the second distance and the environment UV index information with a preset mapping table. The intelligent adjusting mechanism remarkably improves the use comfort and safety of the cosmetic mirror.

Description

Technical Field

[0001] The present invention relates to the technical field of light regulation of beauty products, and particularly to a method for adjusting UV light intensity. Background Art

[0002] With the increasingly serious global warming caused by global climate change, the intensity of UV (Ultra Violet) in solar radiation has increased, and the harm to human skin has also increased accordingly. This has promoted the improvement of sun protection awareness, and the types of sun protection products on the market have become more and more diverse. In order to enable consumers to use these products more effectively and ensure that the sun protection products can be evenly applied to the skin, especially in sensitive areas such as the face, a sun protection makeup mirror combined with a UV camera has emerged. This makeup mirror uses a UV camera to capture the reflected light after the sun protection product is applied to the face and displays the image on the screen, allowing the user to clearly see the coverage of the sun protection product on the skin, so as to judge whether there are missed areas.

[0003] These sun protection makeup mirrors mainly rely on the light emitted by UV LEDs to irradiate the human face, and the reflected light is received by the UV camera. However, UV is an invisible light. If its intensity is too strong or the usage time is too long, it may cause damage to the eyes or skin. On the contrary, if the UV light is too weak, it may affect the imaging effect of the UV camera. Therefore, the distance between the handheld sun protection mirror and the face becomes a key factor in adjusting the UV light intensity.

[0004] In view of this, how to solve the above problems has become a problem to be solved in the technical field. Summary of the Invention

[0005] The main object of the present invention is to provide a method for adjusting UV light intensity and a makeup mirror. In order to solve the problem of possible UV light damage caused by long-term close use of a sun protection mirror, the present invention proposes an innovative technical solution: using face detection technology to judge various distances between the human face and the camera, and automatically adjusting the light intensity of the UV LED according to these distances. In addition, the present invention can also monitor the changes in facial feature points (such as the position of the human eyes) to ensure that the eyes will not stay under high-intensity UV light for a long time.

[0006] For the above purposes, the present invention provides a method for adjusting UV light intensity, which is applicable to a dressing mirror with a UV fill light. The method includes the following steps: capturing a facial image of a user through at least one camera; capturing ambient UV index information through a UV index sensor; performing face recognition and respectively configuring a first coordinate and a second coordinate for two corresponding feature points on the left and right faces in the facial image; calculating a first distance between the first coordinate and the second coordinate; calculating an angle between the at least one camera and the first coordinate and the second coordinate according to the first distance, the image width of the facial image, and the angle of the horizontal field of view; calculating a second distance from the at least one camera to the two feature points according to the angle and the first distance using trigonometric functions; and adjusting the light intensity of the UV light provided by the UV fill light by comparing a preset mapping table according to the second distance and the ambient UV index information.

[0007] Among them, the method further includes: re-executing the above steps through a preset timing to adjust the UV light intensity. Further, this step further includes: calculating a first position change amount and a second position change amount of the two feature points at two consecutive time points; calculating a distance change amount between the user's face and the camera between two consecutive measurement time points; when at least one of the first position change amount, the second position change amount, and the distance change amount exceeds a change threshold, adjusting the UV light intensity.

[0008] Among them, the method further includes: when at least one of the first position change amount, the second position change amount, and the distance change amount exceeds a no-change threshold, providing a warning message or turning off the UV fill light.

[0009] Among them, the at least one camera is at least one of a visible light camera and a UV light camera.

[0010] Among them, the calculation formula for the angle is B = n / w * HFOV.

[0011] Among them, the calculation formula for the second distance is h = (n / 2) * cotβ.

[0012] Among them, the two feature points are a facial part corresponding to the left and right faces of the user, and the facial part has two corresponding parts on the face.

[0013] Among them, the facial part is an eye, an eyebrow, an ear, a cheekbone, or a nasal wing.

[0014] The present invention further provides a makeup mirror, comprising: at least one camera, a UV index sensor, a UV fill light, and a processing unit. The at least one camera is configured to provide a facial image. The UV index sensor is configured to provide ambient UV index information. The UV fill light is configured to provide UV light. The processing unit is signal-connected to the at least one camera, the UV index sensor, and the UV fill light, and performs the following steps: capturing a facial image of a user through the at least one camera; capturing ambient UV index information through the UV index sensor; performing face recognition, and respectively configuring a first coordinate and a second coordinate for two corresponding feature points of the left face and the right face in the facial image; calculating a first distance between the first coordinate and the second coordinate; calculating an angle between the at least one camera and the first coordinate and the second coordinate according to the first distance, the image width of the facial image, and the angle of the horizontal field of view; calculating a second distance from the at least one camera to the two feature points according to the angle and the first distance using trigonometric functions; and comparing a preset mapping table according to the second distance and the ambient UV index information, and adjusting the light intensity of the UV light provided by the UV fill light.

[0015] Wherein, the at least one camera is at least one of a visible light camera and a UV light camera, and is configured to provide at least one of a visible light image and a UV image.

[0016] Wherein, the makeup mirror further comprises a display unit configured to display the facial image. Further, the display unit is a thin film transistor liquid crystal display or a reflective liquid crystal display.

[0017] Compared with the prior art, the present invention not only improves the usage effect of sunscreen products, but also protects the health of users, especially the safety of eyes. By automatically adjusting the intensity of UV light, the present invention allows users to safely and effectively check the evenness of sunscreen application, while avoiding potential harm of UV light.

[0018] The following will be described in detail through specific embodiments in conjunction with the accompanying drawings, and it will be easier to understand the purpose, technical content, features and achieved effects of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is the first flowchart of the UV light intensity adjustment method according to the embodiment provided by the present invention;

[0020] Figure 2 is the second flowchart of the UV light intensity adjustment method according to the embodiment provided by the present invention;

[0021] Figure 3 is the first block diagram of the makeup mirror according to the embodiment provided by the present invention;

[0022] Figure 4The second block diagram of the dressing mirror according to the embodiment provided by the present invention.

[0023] Explanation of reference numerals in the drawings: S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, S12, S13, S14 - steps; 300 - dressing mirror; 310 - camera; 312 - visible light camera; 314 - UV light camera; 320 - UV index sensor; 330 - UV fill light; 340 - processing unit; 350 - display unit. Detailed implementation manners

[0024] Embodiments of the present invention will be further explained below in conjunction with relevant drawings. As much as possible, in the drawings and the specification, the same reference numerals represent the same or similar components. In the drawings, for the sake of simplicity and convenience of marking, the shapes and thicknesses may be exaggerated. It can be understood that the elements not specifically shown in the drawings or described in the specification are in the forms known to those of ordinary skill in the art in the relevant technical field. Those of ordinary skill in the art can make various changes and modifications according to the content of the present invention.

[0025] Please refer to Figure 1 , Figure 1 The first flowchart of the method for adjusting the UV light intensity according to the embodiment provided by the present invention.

[0026] As Figure 1 , this embodiment provides a method for adjusting the UV light intensity, which is applicable to a dressing mirror with a UV fill light. The method includes the following steps:

[0027] Step S1, capturing the facial image of the user through at least one camera.

[0028] Step S2, capturing the ambient UV index information through a UV index sensor.

[0029] Step S3, performing face recognition, and respectively configuring the first coordinate and the second coordinate for two corresponding feature points on the left face and the right face in the facial image.

[0030] Step S4, calculating the first distance between the first coordinate and the second coordinate.

[0031] Step S5, calculating the angle between at least one camera and the first coordinate and the second coordinate according to the first distance, the image width of the facial image, and the angle of the horizontal field of view.

[0032] The calculation formula for the angle is B = n / w * HFOV, and the detailed description of this formula is as follows:

[0033] B represents the angle, for example, it can be the viewing angle between the camera and two feature points (such as eyes);

[0034] n is the distance between two feature points, for example, it can be the distance between the right eye and the left eye;

[0035] w is the total width of the image;

[0036] HFOV is the angle of the horizontal field of view, which is the horizontal range that the camera lens can cover.

[0037] B = n / w * HFOV. This formula calculates an angle B based on the position and size of the face in the image and the field of view angle of the camera. This angle can be used to determine the irradiation range of the UV light provided by the UV fill light to ensure that the user receives appropriate UV light irradiation when using the dressing mirror. B = n / w * HFOV is very important for applications that need to adjust the illuminance according to the position and distance of the user, such as dressing mirrors, photographic lighting adjustment, or other situations that require precise control of lighting conditions.

[0038] Step S6, calculate the second distance from at least one camera to two feature points according to the included angle and the first distance using trigonometric functions.

[0039] The calculation formula for the second distance is h = (n / 2) * cotβ, and this formula is detailed as follows:

[0040] n is the distance between two feature points, for example, it can be the distance between the right eye and the left eye;

[0041] β is the average angle from the camera to two feature points (for example, it can be the user's eyes);

[0042] h is the average distance from the camera to two feature points of the user (for example, the distance from the camera to the user's eyes).

[0043] h = (n / 2) * cotβ. This formula is a half-angle formula, where cot(β) is the cotangent function, which is the cosine of the angle divided by the sine. This formula calculates the average distance from the camera to two feature points by dividing the horizontal distance by 2 (that is, n / 2) and then multiplying by the cotangent (cot). The purpose of doing this is to use the geometric relationship of a triangle to find the length of the unknown side (h). And the angle β may be calculated based on face recognition or obtained through other methods. The calculation of the angle β and the distance can be used to automatically adjust the irradiation intensity of the UV light in the dressing mirror to adapt to the position and distance of the user. The calculation of h = (n / 2) * cotβ plays a key role in accurately measuring and calibrating the light intensity of the UV fill light in the dressing mirror.

[0044] Step S7, compare the second distance and the environmental UV index information with a preset mapping table to adjust the luminous intensity of the UV light provided by the UV fill light.

[0045] Specifically, the enantiomeric table reference adjusts the photometric intensity of the UV light based on the reference guidelines for the determination of occupational photokeratoconjunctivitis (as shown in Table 1).

[0046] Table 1: Reference guidelines for the determination of occupational photokeratoconjunctivitis

[0047]

[0048] According to Table 1 and another embodiment, the dressing mirror applying the UV photometric intensity adjustment method can calculate that at the distance between the current camera and the user's face (such as 5 to 30 cm), for example, the UV photometric intensity received by the face should not exceed a preset effective photometric intensity (such as 1.7 μW). When it exceeds 1.7 μW, the photometric intensity of the UV supplementary light provided is adjusted. Among them, for the distance between the camera and the user's face, the UV photometric intensity per centimeter can be calculated by a power meter to ensure that the photometric intensity received by the user's face does not exceed the daily exposure time, for example, to avoid being exposed to a UV photometric intensity of 1.7 μW for more than 30 minutes.

[0049] The calculation of the UV photometric intensity per centimeter can be, for example, measuring the UV photometric intensity received by a face at a known distance between the face and the camera, and then calculating the UV photometric intensity at each interval (such as per centimeter) within the known distance according to Beer's Law.

[0050] The formula of Beer's Law is A = ε * l * c, and this formula is detailed as follows:

[0051] A is absorbance, dimensionless, which is a measure of the amount of light absorbed by a solution. In this embodiment, the solution is air;

[0052] ε is the molar absorptivity or molar extinction coefficient, with the unit of L·mol-1·cm-1, which is a measure of the absorption ability of a substance in a solution to light of a specific wavelength.

[0053] For example, the molar absorptivity of air;

[0054] l is the path length, with the unit of centimeter, indicating the distance that light passes through the solution. In this embodiment, the light is UV light;

[0055] c is the concentration of the solute, with the unit of mole per liter (mol / L), indicating the amount of the light-absorbing substance in the solution.

[0056] In summary, when the user approaches the dressing mirror, the dressing mirror automatically adjusts the intensity of the UV light to ensure that the user can adjust the appropriate amount of UV light applied to the user's face according to the user's distance from the camera and the UV index in the current environment. For example, if the UV index is very high, the dressing mirror will reduce the UV light irradiation to reduce the damage to the user's skin and eyes; on the contrary, if the UV index is low, the UV light irradiation can be increased so that the user has sufficient light when applying makeup or skin care, and it can also provide an image for judging the application status of sunscreen. The above intelligent adjustment mechanism can greatly increase the comfort and safety of using the dressing mirror.

[0057] Please refer to Figure 2 , Figure 2 which is the second flowchart of the method for adjusting the UV light intensity of the embodiment provided by the present invention.

[0058] As Figure 2 , according to another embodiment, after completing steps S1 to S7, the following steps are further included:

[0059] Step S8, by means of pre-designed timing, re-execute the above steps (steps S1 to S7) to adjust the UV light intensity.

[0060] Specifically, step S8 is to use a timer to periodically (every N milliseconds) measure and update the coordinates of two feature points (such as eyes) of the user and the distance from the face to the camera. These measurement data will be used for further processing, such as automatic adjustment of UV light irradiation.

[0061] Step S9, calculate a first position change amount and a second position change amount of the two feature points at two consecutive time points.

[0062] Specifically, the coordinates of the two feature points are Ln and Rn respectively. Each time the timer is triggered, the dressing mirror will identify and record the coordinates of the first feature point (Ln) and the second feature point (Rn) of the user (such as the coordinates of the left eye and the right eye). The Ln and Rn coordinates can be obtained from the face image captured by the camera through image processing technology. The distance from the face to the camera is Hn, and the dressing mirror will also calculate the distance Hn from the face to the camera. The distance Hn can be estimated according to the change in the size of the face feature points, because the size of the feature points will change with the change in the distance from the camera. n is the current index value, indicating that this is the nth measurement. The n index value can be used to track time series data for convenient data storage and subsequent analysis.

[0063] Step S10, calculate a distance change amount of the user's face to the camera between two consecutive measurement time points.

[0064] The formula for the distance change amount is

[0065] Ld = |LX(n - 1) - LXn| + |LY(n - 1) - Lyn|;

[0066] Rd = |RX(n - 1) - LXn| + |RY(n - 1) - Lyn|;

[0067] Hd = |H(n - 1) - LHn| + |H(n - 1) - LHn|.

[0068] If Ld < thL then Lv is incremented by 1, otherwise cleared;

[0069] If Rd < thR then Rv is incremented by 1, otherwise cleared;

[0070] If Hd < thH then Hv is incremented by 1, otherwise cleared.

[0071] The detailed description of the above formulas is as follows:

[0072] Ld (change amount of feature point, such as the change amount of the left eye coordinate): Taking the left eye as an example of the feature point, it is the position change amount of the left eye feature point between two consecutive measurement time points, calculated as the sum of the absolute values of the differences in the X coordinate and the Y coordinate between the previous time point and the current time point;

[0073] Rd (change amount of feature point, such as the change amount of the right eye coordinate): Taking the right eye as an example of the feature point, it is the position change amount of the right eye feature point between two consecutive measurement time points, calculated in the same way as Ld, but using the coordinates of the right eye;

[0074] Hd (change amount of distance): It is the change amount of the distance between the user's face and the camera between two consecutive measurement time points;

[0075] thL (threshold of left eye coordinate change): It is the threshold of the left eye coordinate change amount. When Ld is less than this threshold, the system increments the corresponding variable Lv by 1, otherwise clears Lv;

[0076] thR (threshold of right eye coordinate change): It is the threshold of the right eye coordinate change amount. When Rd is less than this threshold, the system increments the corresponding variable Rv by 1, otherwise clears Rv;

[0077] thH (threshold of distance change): It is the threshold of the distance change amount. When Hd is less than this threshold, the system increments the corresponding variable Hv by 1, otherwise clears Hv.

[0078] The calculations of Ld, Rd, and Hd, as well as the corresponding thL, thR, and thH, are used to determine whether there are significant movements in the facial feature points (Ld, Rd) of the user and the distance (Hd) between the face and the camera. When the movement is less than the set thresholds (thL, thR, or thH), this may indicate minor movements or changes in the user's facial expressions. If the change amount exceeds the threshold, this may indicate a large range of movement of the user's face or a change in the position of the dressing mirror. Such change amounts and the update of the counter may affect the adjustment judgment of the UV light intensity. For example, if the user remains stationary, it may not be necessary to adjust the UV illuminance, but if frequent movements are detected, the dressing mirror may increase or decrease the lighting intensity based on these movements and the UV index. Such an automated method can provide a more personalized and adaptable lighting solution.

[0079] Step S11, determine whether at least one of the first position change amount, the second position change amount, and the distance change amount exceeds the change threshold. If so, continue to step S12; if not, jump to step S13.

[0080] Step S12, adjust the UV light intensity.

[0081] Step S13, determine whether at least one of the first position change amount, the second position change amount, and the distance change amount exceeds the no-change threshold. If so, continue to step S14; if not, return to step S8.

[0082] As the formula applied in step S10, it can also be the following formula:

[0083] Ld = |LX(n - 1) - LXn| + |LY(n - 1) - Lyn|;

[0084] Rd = |RX(n - 1) - LXn| + |RY(n - 1) - Lyn|;

[0085] Hd = |H(n - 1) - LHn| + |H(n - 1) - LHn|.

[0086] If Ld < thL, then Lv is incremented by 1; otherwise, it is cleared to zero;

[0087] If Rd < thR, then Rv is incremented by 1; otherwise, it is cleared to zero;

[0088] If Hd < thH, then Hv is incremented by 1; otherwise, it is cleared to zero.

[0089] The above formulas are detailed as follows:

[0090] Ld, Rd, Hd, thL, thR, thH: have been described previously and will not be elaborated here;

[0091] Lv (the number of times the coordinates of the feature point stay, e.g., the cumulative number of times the coordinates of the left eye stay): Taking the left eye as an example of the feature point, when the position change of the left eye is less than thL, this number increases; otherwise, it is reset to zero.

[0092] Rv (the number of times the coordinates of the feature point stay, e.g., the cumulative number of times the coordinates of the right eye stay): Taking the right eye as an example of the feature point, when the position change of the right eye is less than thR, this number increases; otherwise, it is reset to zero.

[0093] Hv (the cumulative number of times the face stays): When the distance change between the face and the camera lens is less than thH, this number increases; otherwise, it is reset to zero.

[0094] Furthermore, if the cumulative number of any one of the above Lv, Rv, and Hv exceeds the cumulative number of times of the no-change threshold, the makeup mirror can also directly turn off the LED to prevent the user's face from being overly exposed to UV light. This automated safety mechanism helps ensure the safety of the user, especially in applications that require precise control of UV light intensity, such as the UV light supplement of a makeup mirror.

[0095] Specifically, if Lv, Rv, and Hv all exceed the set no-change threshold, the makeup mirror will give a prompt and issue a warning, indicating that the user has stayed within the range of UV light irradiation for too long. For example, if the coordinates of the human eye stop within the range of UV light irradiation and are less than the distance H (the distance between the face and the camera, e.g., 5 to 30 cm), a warning message will be issued. If the situation continuously accumulates more than 10 times (e.g., Lv, Rv, or Hv accumulates to 10), the UV light will be forcibly turned off or the intensity of the UV light will be adjusted.

[0096] Step S14, provide a warning message or turn off the UV light supplement lamp.

[0097] Please refer to Figure 3 , Figure 3 which is the first block diagram of the makeup mirror according to the embodiment provided by the present invention.

[0098] As Figure 3, According to another embodiment, a makeup mirror 300 is provided, comprising: at least one camera 310, a UV index sensor 320, a UV fill light 330, and a processing unit 340. The at least one camera 310 is configured to provide a facial image. The UV index sensor 320 is configured to provide ambient UV index information. The UV fill light 330 is configured to provide UV light. The processing unit 340 is signal-connected to the at least one camera 310, the UV index sensor, and the UV fill light 330, and performs the following steps: capturing a facial image of a user through the at least one camera 310; capturing ambient UV index information through the UV index sensor 320; performing face recognition, and respectively configuring a first coordinate and a second coordinate for two corresponding feature points on the left face and the right face in the facial image; calculating a first distance between the first coordinate and the second coordinate; calculating an angle between the at least one camera 310 and the first coordinate and the second coordinate according to the first distance, the image width of the facial image, and the angle of the horizontal field of view; calculating a second distance from the at least one camera 310 to the two feature points according to the angle and the first distance using trigonometric functions; and comparing the second distance and the ambient UV index information with a preset mapping table to adjust the brightness of the UV light provided by the UV fill light 330.

[0099] According to yet another embodiment, the steps performed by the processing unit 340 are Figure 1 the aforementioned steps S1 to S7. Alternatively, after performing steps S1 to S7, further perform at least one of the steps Figure 2 S8 to S14 as required. For example, through the preset timing of step S8, the makeup mirror 300 can repeatedly execute steps S1 to S7 at regular intervals to monitor the exposure of the user's face to UV light. Furthermore, through steps S9 to S12, the processing unit 340 can determine whether there is a significant change in the position of the user in front of the camera 310 to adjust the UV brightness provided by the UV fill light 330. In addition, through steps S13 to S14, the processing unit 340 can determine whether the user has stayed in front of the camera 310 for a long time (for example, after the user uses the makeup mirror 300 and forgets to turn it off). At this time, the user may receive excessive UV brightness provided by the UV fill light 330 under non-essential circumstances (for example, the user has actually finished using the makeup mirror 300 to confirm the application status of sunscreen and is watching TV, but the makeup mirror 300 remains on). Therefore, to prevent the user from being exposed to excessive UV light, the processing unit 340 will provide a warning message or directly turn off the UV fill light 330. The warning message can be provided as an audible warning through a speaker (not shown).

[0100] The processing unit 340 can be, for example, a computer device with data processing and image processing capabilities, such as a microcontroller unit.

[0101] Please refer to Figure 4 。 Figure 4 This is the second block diagram of the makeup mirror according to the embodiment provided by the present invention.

[0102] As Figure 4 , according to another embodiment, at least one of the cameras 310 is at least one of a visible light camera 312 and a UV light camera 314, for providing at least one of a visible light image (provided by the visible light camera 312) or a UV image (provided by the UV light camera 314).

[0103] As Figure 4 , according to yet another embodiment, the makeup mirror 300 further includes a display unit 350 for displaying a face image. Further, the display unit 350 is a thin film transistor liquid crystal display or a reflective liquid crystal display. Therefore, when the display unit does not display the face image, according to the characteristics of the selected display of the display unit 350, it can also be used as a mirror. Moreover, the display unit 350 can also be used to display the visualized warning information.

[0104] Moreover, when the makeup mirror 300 has both a visible light camera 312 and a UV light camera 314 at the same time, the processing unit 340 can also select at least one region of interest (ROI) within at least one approximate region of the visible light image and the UV image, and perform image alignment on at least one region of interest associated with the visible light image and the UV image, so as to generate a composite image. In this way, the display unit 350 can also display the composite image to allow the user to confirm the application status of the sunscreen.

[0105] The region of interest can be, for example, a single pixel or a region composed of a plurality of pixels (such as the facial features of a human face). The region of interest can be, for example, some key points, and the key points include contours, edges, and corners. Taking a human face as an example, the key points can be, for example, the contours, edges, and corners of facial features such as eyes, nose, mouth, between the eyebrows, chin, and ears.

[0106] As described above, it is only an example to illustrate the preferred embodiments of the present invention, and is not intended to limit the scope of implementation. All simple substitutions and equivalent changes made according to the claims and the content of the specification of the present invention fall within the scope covered by the present invention.

Claims

1. A method for adjusting UV light intensity, applicable to a dressing mirror with a UV supplementary lamp, characterized in that, The method includes the following steps: Capture a facial image of a user through at least one camera; Capture environmental UV index information through a UV index sensor; Perform face recognition, and respectively assign a first coordinate and a second coordinate to two corresponding feature points on the left face and the right face in the facial image; Calculate a first distance between the first coordinate and the second coordinate; Calculate an included angle between the at least one camera and the first coordinate and the second coordinate according to the first distance, an image width of the facial image, and an angle of a horizontal field of view; Calculate a second distance from the at least one camera to the two feature points according to the included angle and the first distance using trigonometric functions; and Compare a preset mapping table according to the second distance and the environmental UV index information, and adjust the luminosity of a UV light provided by the UV fill light.

2. The method for adjusting the UV light intensity according to claim 1, characterized in that, The method further includes the following steps: Re-execute the steps described in claim 1 through a preset timing to adjust the UV luminosity.

3. The method for adjusting the UV light intensity according to claim 2, characterized in that Re-executing the steps described in claim 1 to adjust the UV luminosity further includes the following steps: Calculate a first position change amount and a second position change amount of the two feature points at two consecutive time points; Calculate a distance change amount between the user's face and the camera between two consecutive measurement time points; When at least one of the first position change amount, the second position change amount, and the distance change amount exceeds a change threshold, then adjust the UV luminosity.

4. The method for adjusting the UV light intensity according to claim 3, characterized in that, The method further includes: When at least one of the first position change amount, the second position change amount, and the distance change amount exceeds a no-change threshold, then provide a warning message or turn off the UV fill light.

5. The adjustment method of UV light intensity according to claim 1, characterized in that The at least one camera is at least one of a visible light camera and a UV light camera.

6. The method for adjusting the UV light intensity according to claim 1, characterized in that, The calculation formula for the included angle is B = n / w * HFOV.

7. The method for adjusting the UV light intensity according to claim 1, wherein The calculation formula for the second distance is h = (n / 2) * cotβ.

8. The method for adjusting the UV light intensity according to claim 1, characterized in that The two feature points are two corresponding facial parts on the left face and the right face of the user, and the facial parts are two corresponding parts on the face.

9. The method for adjusting the UV light intensity according to claim 8, characterized in that, The facial parts are eyes, eyebrows, ears, cheekbones, or nasal wings.

10. A makeup mirror, characterized in that, Includes: At least one camera for providing a facial image; A UV index sensor for providing environmental UV index information; A UV fill light for providing UV light; A processing unit, signal-connected to the at least one camera, the UV index sensor, and the UV fill light, and performing the following steps: Capture a facial image of a user through the at least one camera; Capture the environmental UV index information through the UV index sensor; Perform face recognition, and respectively assign a first coordinate and a second coordinate to two corresponding feature points on the left face and the right face in the facial image; Calculate a first distance between the first coordinate and the second coordinate; Calculate an included angle between the at least one camera and the first coordinate and the second coordinate according to the first distance, an image width of the facial image, and an angle of a horizontal field of view; Calculate a second distance from the at least one camera to the two feature points according to the included angle and the first distance using trigonometric functions; And Compare a preset mapping table according to the second distance and the environmental UV index information, and adjust the luminous intensity of the UV light provided by the UV supplementary light.

11. The cosmetic mirror according to claim 10, characterized in that, The at least one camera is at least one of a visible light camera and a UV light camera, and is configured to provide at least one of a visible light image and a UV image.

12. The cosmetic mirror according to claim 10, characterized in that, It further includes a display unit configured to display the face image.

13. The cosmetic mirror according to claim 12, characterized in that, The display unit is a thin film transistor liquid crystal display or a reflective liquid crystal display.

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