Ambient light detection system and method for an electronic device

Abstract

An ambient light detection system for an electronic device includes a light sensor, a processing unit, and a subtractor. The light sensor is located below the display of the electronic device and is used to sense ambient light during a sensing period to generate a first sense value. The display sequentially displays L images based on L pieces of image data during the sensing period, wherein each piece of image data includes M first pixel color values ​​and a first backlight level. The processing unit obtains a predicted value based on the N×L first pixel color values ​​corresponding to N pixels in the display, N color weight parameters, and L first backlight levels. The subtractor subtracts the predicted value from the first sense value to obtain an ambient light sense value.

Description

Technical Field

[0001] The present invention relates to an ambient light detection system and method for an electronic device, and particularly to a system and method for detecting ambient light below a display. Prior Art

[0002] With the development of technology, it has become a current trend for mobile devices with displays to pursue a high screen-to-body ratio. In addition, due to the light-transmitting characteristics of OLED displays, many optical sensors that were originally placed around the mobile phone bezel, such as fingerprint recognition, ambient light sensors (ALS), proximity sensors (PS), etc., have been moved under the display screen. For ALS applications, when detecting the intensity of external ambient light, it is inevitable to receive the light emitted by the OLED screen, so the obtained ambient light value will have errors.

[0003] An existing method for sensing under-screen ambient light is to use the extremely short blanking period between frames when the display shows an image to perform ambient light sensing. During the blanking period, the brightness of the display will decrease or even go completely dark. Therefore, performing ambient light sensing during this period can reduce the interference of the display. However, the biggest drawback of this method is that when the duration of the blanking period is very short (e.g., less than 300 milliseconds), the time during which the optical sensor can perform sensing (or called the integration time) is quite short. The short sensing time of the optical sensor will lead to insufficient sensitivity and misjudgment, especially in low-illumination environments. Therefore, the existing under-screen ambient light sensing method needs to be further improved. Summary of the Invention

[0004] One of the objectives of the present invention is to provide an ambient light detection system and method for an electronic device.

[0005] According to the present invention, an ambient light detection system for an electronic device, the electronic device includes a transmissive display that sequentially displays L images according to L sets of image data during a sensing period, wherein each set of the image data includes M first pixel color values and a first backlight level, and L is a positive integer greater than or equal to 1. The ambient light detection system includes a light sensor, a processing unit, and a subtractor. The light sensor is located below the display for sensing ambient light during the sensing period to generate a first sensed value. The processing unit obtains an estimated value based on the N×L first pixel color values corresponding to N pixels in the display, N color weight parameters, and L of the first backlight levels, where N is a positive integer less than M and greater than 1. The subtractor is connected to the light sensor and the processing unit, and subtracts the estimated value from the first sensed value to obtain an ambient light sensed value.

[0006] According to the present invention, an ambient light detection system for an electronic device, the electronic device includes a transmissive display that sequentially displays L images according to L sets of image data during a sensing period, wherein each set of the image data includes M pixel color values and a backlight level, and L is a positive integer greater than or equal to 1. The ambient light detection system includes a light sensor, a processing unit, and a subtractor. The light sensor is located below the display for sensing ambient light during the sensing period to generate a first sensed value. The processing unit obtains an estimated value based on the N×L first pixel intensity values corresponding to N pixels in the display, N color weight parameters, and L of the first backlight intensities, where N is a positive integer less than M and greater than 1. Each of the first pixel intensity values is determined by the pixel color values corresponding to the same pixel in the L sets of image data. The L first backlight intensities are determined by the backlight levels of the L sets of image data. The subtractor is connected to the light sensor and the processing unit, and subtracts the estimated value from the first sensed value to obtain an ambient light sensed value.

[0007] According to the present invention, an ambient light detection method for an electronic device, the electronic device includes a transmissive display that sequentially displays L images according to L sets of image data during a sensing period, wherein each set of the image data includes M first pixel color values and a first backlight level, and L is a positive integer greater than or equal to 1. The ambient light detection method includes: sensing ambient light through a light sensor to generate a first sensed value; obtaining an estimated value based on the N×L first pixel color values corresponding to N pixels in the display, N color weight parameters, and L of the first backlight levels, where N is a positive integer less than M and greater than 1; and subtracting the estimated value from the first sensed value to obtain an ambient light sensed value. Brief Description of the Drawings

[0008] shows a first embodiment of an electronic device using an ambient light detection system of the present invention. 2 shows an embodiment of the image processor in FIG. Figure 3 shows an embodiment of the color value-to-intensity conversion function. 4 shows an embodiment of a backlit plasma dimming curve. 5 shows a first embodiment of the flow of operations performed by the processing unit in FIG. 6 shows a second embodiment of the flow of operations performed by the processing unit in FIG. 7 shows a second embodiment of an electronic device using an ambient light detection system of the present invention. 8 shows an embodiment of the flow of operations performed by the processing unit in FIG. 7 to obtain the estimated value. Figure 9 shows a flowchart of the ambient light detection method of the present invention. 10 is an embodiment for obtaining N color weight parameters for N pixels. Implementation

[0009] shows a first embodiment of an electronic device using an ambient light detection system of the present invention. The electronic device 10 of FIG. 1 may be, but is not limited to, a mobile device such as a mobile phone or tablet. The electronic device 10 includes an ambient light detection system 12 , an image processor 14 , a driver unit 16 and a display 18 . The image processor 14 is used to receive and process image data to generate a display data Ddis, wherein each stroke of the image data includes M pixel color values ​​DC and a backlight plasma DBL. Each pixel color value DC is a pixel in the corresponding display 18. The pixel color value DC is used to determine the color intensity of the corresponding pixel. The backlight plasma DBL is used to determine the backlight intensity of the display 18 . The driver unit 16 drives the display 18 according to the display data Ddis output by the image processor 14 to cause the display 18 to display an image corresponding to the image data. The display 18 is a light-transmitting display, which may be, but is not limited to, an OLED display. The display 18 includes M pixels corresponding to the M pixel color value DC, respectively. In one embodiment, the M pixels include a plurality of red light emitting pixels, a plurality of green light emitting pixels, and a plurality of blue light emitting pixels.

[0010] 2 shows an embodiment of the image processor 14 in FIG. The image processor 14 of FIG. The color intensity conversion unit 142 converts the pixel color value DC to the pixel color intensity value DCi by a color value-to-intensity conversion function. The color value-to-intensity conversion function can be, but is not limited to, the curve shown in Figure 3 . The backlight intensity conversion unit 146 converts the backlight plasma DBL to the backlight intensity DBLi through a backlight plasma dimming curve. The backlight plasma dimming curve may be, but is not limited to, the curve shown in Figure 4 . The multiplier 144 multiplies the pixel color intensity value DCi with the backlight intensity DBLi to obtain the display data Ddis. In Figure 2 the image processor 14 is implemented in hardware, but the image processor 14 can also be implemented in software.

[0011] In an embodiment of FIG. The light sensor 122 is located below the display 18 and is used to sense ambient light during a sensing to produce a sense value C Sensor. During that sensing, the display 18 sequentially displays L images based on L pen image data, where L is a positive integer greater than or equal to 1. In other words, the sensing period is the length of time for displaying L images. The processing unit 126 obtains an estimated C OLED during that sensing based on N × L pixel color values ​​DC and N color weight parameters corresponding to N pixels in display 18 and L backlight plasma DBL, where N is a positive integer less than M and greater than 1. Estimate C OLED is an estimate of the intensity of the light from display 18 hitting the light sensor 122 . In this embodiment, the N pixels refer to pixels in the sensing range of the light sensor 122 . The color weight parameter is the default value set by the electronic device 10 at the factory. Each pixel corresponds to a color weight parameter. When a pixel in the sensing range of the light sensor 122 emits light, it causes the light sensor 122 to produce the luminous intensity of the pixel multiplied by the sensor value of its corresponding one color weight parameter. The subtractor 124 has a positive and a negative input connected to a light sensor 122 and a processing unit 126 , respectively. Subtractor 124 is used to subtract the sensed value C Sensor from the estimated value C OLED to obtain an ambient light sensed value C Ambient=C Sensor-C OLED.

[0012] 5 shows a first embodiment of an operating flow performed by processing unit 126 in FIG. Referring to FIG. 5 , steps S10 and S12 are performed after obtaining the aforementioned N × L pixel color value DC and L backlight plasma DBL of the L pen image data at the processing unit 126 . In step S10, the processing unit 126 averages the L pen pixel color value DC corresponding to the same pixel in the L pen image data to obtain N pixel color value DCavg, respectively. In step S12, the processing unit 126 averages the backlight plasma DBL of the L pen image data to obtain the backlight plasma DBLavg. Step S10 and step S12 of FIG. In the case of L=1, the pixel color value DC is equal to the pixel color value DCavg, and the backlight grade DBL is equal to the backlight grade DBLavg. After step S10 is completed, proceed to step S14. In step S14, the processing unit 126 converts N pixel color values ​​DCavg to N pixel color intensity values ​​DCi. In this embodiment, a color weight parameter corresponds to a pixel color intensity value DCi. After step S12 is completed, proceed to step S16. In step S16, the processing unit 126 converts the backlight plasma DBLavg to one backlight intensity DBLi according to the actual backlight plasma dimming curve. The backlight plasma dimming curve referred to here may be, but is not limited to, the curve shown in Fig. 4 . After step S14 is completed, proceed to step S18. In step S18, the processing unit 126 multiplies the N pixel color intensity values ​​DCi with the corresponding color weight parameters, respectively, to obtain a plurality of products. After step S18 is completed, proceed to step S20. In step S20, the processing unit 126 sums the plurality of products to obtain a sum value. After both step S16 and step S20 have been completed, proceed to step S22. In step S22, the processing unit 126 multiplies that sum value, the backlight intensity DBLi, and a tuning factor to obtain the estimated C OLED, where the tuning factor is the default value and is correlated with the set parameters of the light sensor 122 . In other embodiments, step S22 may also use other operations to generate the estimated C OLED.

[0013] From the above description in Figure 5 when it can be understood that the estimated value of C OLED can be expressed by the following formula: C OLED=α×[Sum(WR×IR)+Sum(WG×IG)+Sum(WB×IB)]×DBLi Formula 1 Among them, α is the adjustment coefficient, WR is the color weight array of the color weight parameters of the red light pixels, WG is the color weight array of the color weight parameters of the green light pixels, WB is the color weight array of the color weight parameters of the blue light pixels, IR is the color intensity array corresponding to the pixel color intensity value DCi of the red light pixels, IG is the color intensity array corresponding to the pixel color intensity value DCi of the green light pixels, and IB is the color intensity array corresponding to the pixel color intensity value DCi of the blue light pixels. The function of the adjustment coefficient α is to amplify or reduce the final estimated value COLED. Because there may be a fixed magnification relationship between the estimated value and the sensed value of the light sensor 122 due to settings such as the gain magnification and integration time of the light sensor 122 and the maximum emission intensity of the display. The adjustment coefficient α is the parameter used to adjust the scale of the estimated value COLED and can be obtained by dividing the sensed value by the estimated value.

[0014] FIG. 6 shows a second embodiment of the operation flow executed by the processing unit 126 in FIG. 1 to obtain the estimated value COLED. Referring to FIG. 6, after the processing unit 126 obtains the N×L pixel color values DC of L pieces of image data and the L backlight levels DBL, steps S30 and S32 are performed. In step S30, the processing unit 126 converts the N pixel color values DC corresponding to the N pixels in each piece of image data into N pixel color intensity values DCi. In step S32, the processing unit 126 converts the backlight levels DBL of L pieces of image data into L backlight intensities DBLi. Steps S30 and S32 in FIG. 6 can be performed simultaneously, or one step can be performed after the other step is completed. After step S30 is completed, step S34 is performed. In step S34, the processing unit 126 averages the L pixel color intensity values DCi corresponding to the same pixel to obtain N pixel color intensity values Dciavg. In this embodiment, a color weight parameter corresponds to one pixel color intensity value Dciavg. After step S32 is completed, step S36 is performed. In step S36, the processing unit 126 averages the L backlight intensities DBLi to obtain a backlight intensity DBLiavg. In the case where L = 1, the pixel color intensity value DCi is equal to the pixel color intensity value Dciavg, and the backlight intensity DBLi is equal to the backlight intensity DBLiavg. After step S34 is completed, step S38 is performed. In step S38, the processing unit 126 multiplies the N pixel color intensity values Dciavg by the corresponding color weight parameters to obtain a plurality of products. After step S38 is completed, step S40 is performed. In step S40, the processing unit 126 adds the plurality of products to obtain a sum value. After steps S36 and S40 are both completed, step S42 is performed. In step S42, the processing unit 126 multiplies the sum value, the backlight intensity DBLiavg, and an adjustment coefficient to obtain the estimated value COLED, where the adjustment coefficient is a preset value and is related to the setting parameters of the light sensor 122.

[0015] From the above description of FIG. 6, it can be understood that the estimated value COLED can be expressed by the following formula: COLED=α×[Sum(WR×IR’)+Sum(WG×IG’)+Sum(WB×IB’)]×DBLiavg Formula 2 Where, IR’ is the color intensity array of the pixel color intensity value Dciavg corresponding to the red light pixel, IG’ is the color intensity array of the pixel color intensity value Dciavg corresponding to the green light pixel, and IB’ is the color intensity array of the pixel color intensity value Dciavg corresponding to the blue light pixel.

[0016] From the foregoing, the main difference in the operating flow of Figures 5 and 6 is that Figure 5 averages the color pixel values ​​DC and backlight plasma DBL before converting them to pixel color intensity values ​​DCi and backlight intensity DBLi.

[0017] 7 shows a second embodiment of an electronic device using an ambient light detection system of the present invention. The electronic device 20 of FIG. 7 may be, but is not limited to, a mobile device such as a mobile phone or tablet. The electronic device 20 like the electronic device 10 of FIG. The difference is that the ambient light detection system 12 of the electronic device 20 obtains the pixel color intensity value DCi of N pixels in the sensing range of the light sensor 122 and the backlight intensity DBLi of the display 18 from the image processor 14 . Assuming that the display 18 sequentially displays L images based on L pen image data during a sensing period, the processing unit 126 of the ambient light detection system 12 will obtain an estimated C OLED based on the N × L pixel color intensity values ​​DCi and N color weight parameters corresponding to the N pixels in the display 18 and L backlight intensity DBLi.

[0018] FIG. 8 shows an embodiment of the operation flow executed by the processing unit 126 in FIG. 7 to obtain the estimated value COLED. Referring to FIG. 8, after the processing unit 126 obtains the N×L pixel color intensity values DCi of L pieces of image data and the L backlight intensities DBLi, steps S50 and S52 are performed. In step S50, the processing unit 126 averages the L pixel color intensity values DCi corresponding to the same pixel to obtain N pixel color intensity values Dciavg. In this embodiment, a color weight parameter corresponds to one pixel color intensity value Dciavg. In step S52, the processing unit 126 averages the L backlight intensities DBLi to obtain a backlight intensity DBLiavg. When L = 1, the pixel color intensity value DCi is equal to the pixel color intensity value Dciavg, and the backlight intensity DBLi is equal to the backlight intensity DBLiavg. Steps S50 and S52 in FIG. 8 can be performed simultaneously, or one step can be performed after the other step is completed. After step S50 is completed, step S54 is performed. In step S54, the processing unit 126 multiplies the N pixel color intensity values Dciavg by the corresponding color weight parameters respectively to obtain a plurality of products. After step S54 is completed, step S56 is performed. In step S56, the processing unit 126 adds the plurality of products to obtain a sum value. After steps S52 and S56 are both completed, step S58 is performed. In step S58, the processing unit 126 multiplies the sum value, the backlight intensity DBLiavg, and an adjustment coefficient to obtain the estimated value COLED, where the adjustment coefficient is a preset value and is related to the setting parameters of the light sensor 122. From the foregoing description, the estimated value COLED can be expressed by the previous formula 2.

[0019] In the embodiments of FIGS. 1 and 7, the processing unit 126 can send the obtained predicted value C OLED each time to the subtractor 124 to obtain the ambient light sensing value C Ambient, or can generate the ambient light sensing value C Ambient when it is determined that the light emission intensity of the display 18 is relatively stable. For example, when the variations of the successively obtained predicted values C OLED are all less than a preset value, the processing unit 126 can determine that the light intensity of the display 18 is relatively stable, and send the current predicted value C OLED to the subtractor 124 to obtain the ambient light sensing value C Ambient. Specifically, assume that three predicted values C OLED1, C OLED2, and C OLED3 are obtained, and the preset value is 5. The largest of these three predicted values is C OLEDMax, and the smallest is C OLEDMin. C OLEDMax - C OLEDMin is the variation range. If the variation range = 4, it is regarded that the variations of the predicted value C OLED are all less than the preset value. Therefore, the processing unit 126 will send the current predicted value C OLED3 to the subtractor 124 to obtain the ambient light sensing value C Ambient.

[0020] From the above description, it can be understood that the ambient light detection method of the present invention can be expressed as shown in FIG. 9, including the following steps: Step S60: Sense ambient light through a light sensor 122 to generate a sensed value C Sensor; Step S62: Obtain a predicted value C OLED according to the N×L pixel color values DC corresponding to N pixels in the display, N color weight parameters, and L backlight levels DBL; and Step S62: Subtract the predicted value C OLED from the sensed value C Sensor to obtain an ambient light sensing value C Ambient.

[0021] FIG. 10 is an embodiment for explaining the acquisition of N color weight parameters of N pixels. The method for setting the color weight parameters includes but is not limited to: (1) setting the backlight intensity (or full-screen brightness) of the display 18 to the maximum value; (2) making the full screen of the display 18 display a black image (i.e., the display 18 does not emit light); (3) lighting up the pixels within the sensing range of the light sensor 122 one by one, and recording the sensed value C Sensor of the light sensor 122 to obtain a sensed value array, as shown in the left figure of FIG. 10; (4) normalizing the sensed value array to generate a color weight parameter array, as shown in the right figure of FIG. 10. In the foregoing step (3), the red pixels, green pixels, and blue pixels must be lit up separately, and the pixel color value DC is set to the maximum value. Since the red pixels, green pixels, and blue pixels are lit up separately, three sensed value arrays corresponding to the red pixels, green pixels, and blue pixels can be obtained in step (3). The normalization operation in the foregoing step (4) is to divide all the sensed values in the sensed value array by the maximum value in the sensed value array.

[0022] The above are only embodiments of the present invention, and do not impose any formal restrictions on the present invention. Although the present invention has been disclosed as above by way of embodiments, it is not intended to limit the present invention. Any person with ordinary knowledge in the technical field can, without departing from the scope of the technical solution of the present invention, make some changes or modifications using the above-disclosed technical content to obtain equivalent embodiments of equivalent changes. However, as long as it does not depart from the content of the technical solution of the present invention, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

[0023] 10: Electronic device 12: Ambient light detection system 122: Light sensor 124: Subtractor 126: Processing unit 14: Image processor 142: Color intensity conversion unit 144: Multiplier 146: Backlight intensity conversion unit 16: Driving unit 18: Display 20: Electronic device

Claims

1. An ambient light detection system for an electronic device, the electronic device comprising a light-transmitting display that sequentially displays L images based on L pieces of image data during a sensing period, wherein each piece of image data comprises M first pixel color values ​​and a first backlight level, and L is a positive integer greater than or equal to 1, the ambient light detection system comprising: A light sensor, located below the display, is used to sense ambient light during the sensing period to generate a first sense value; A processing unit obtains a predicted value based on N×L first pixel color values ​​corresponding to N pixels in the display, N color weight parameters, and L first backlight levels, where N is a positive integer less than M and greater than 1; and a subtractor connected to the light sensor and the processing unit subtracts the predicted value from the first sensing value to obtain an ambient light sensing value; wherein the predicted value is a predicted value of the intensity of light from the display illuminating the light sensor.

2. The ambient light detection system as described in claim 1, wherein the operation of the processing unit includes: The color values ​​of the first pixel corresponding to the same pixel in the L image data are averaged to obtain N second pixel color values; The first backlight level of the L image data is averaged to obtain a second backlight level; the N second pixel color values ​​are converted into N pixel color intensity values, wherein one color weight parameter corresponds to one pixel color intensity value; the second backlight level is converted into a backlight intensity; the N pixel color intensity values ​​are multiplied by their corresponding color weight parameters to obtain multiple products; the multiple products are summed to obtain a total value. The estimated value is obtained by multiplying the sum, the backlight intensity, and an adjustment factor, wherein the adjustment factor is related to the setting parameters of the light sensor.

3. The ambient light detection system as described in claim 1, wherein the operation of the processing unit includes: In each piece of image data, the N color values ​​of the first pixel corresponding to the N pixels are converted into N color intensity values ​​of the first pixel. The color intensity values ​​of the first pixel corresponding to the same pixel are averaged to obtain N second pixel color intensity values, wherein one color weight parameter corresponds to one second pixel color intensity value; the first backlight level of the L image data is converted into L first backlight intensities; the L first backlight intensities are averaged to obtain a second backlight intensity; the N second pixel color intensity values ​​are multiplied by the corresponding color weight parameter to obtain multiple products; the multiple products are summed to obtain a sum value; and the sum value, the second backlight intensity, and an adjustment coefficient are multiplied to obtain the estimated value, wherein the adjustment coefficient is related to the setting parameters of the light sensor.

4. The ambient light detection system of claim 1, wherein when the processing unit receives multiple consecutive estimates whose changes are all less than a preset value, it sends the current estimate to the subtractor to obtain the ambient light sensing value.

5. An ambient light detection system for an electronic device, the electronic device comprising a light-transmitting display that sequentially displays L images based on L pieces of image data during a sensing period, wherein each piece of image data comprises M pixel color values ​​and a backlight level and L is a positive integer greater than or equal to 1, the ambient light detection system comprising: A light sensor, located below the display, is used to sense ambient light during the sensing period to generate a first sense value; A processing unit obtains a predicted value based on N×L first pixel color intensity values ​​corresponding to N pixels in the display, N color weight parameters, and L first backlight intensities, where N is a positive integer less than M and greater than 1; and a subtractor connected to the light sensor and the processing unit subtracts the predicted value from the first sensing value to obtain an ambient light sensing value; wherein each first pixel color intensity value is determined by the pixel color value corresponding to the same pixel in the L image data; wherein the L first backlight intensities are determined by the backlight level of the L image data; wherein the predicted value is a predicted value of the intensity of light from the display illuminating the light sensor.

6. The ambient light detection system as described in claim 5, wherein the operation of the processing unit includes: The color intensity values ​​of the first pixel corresponding to the same pixel are averaged to obtain N second pixel color intensity values, wherein one color weight parameter corresponds to one second pixel color intensity value; the L first backlight intensities are averaged to obtain a second backlight intensity; the N second pixel color intensity values ​​are multiplied by the corresponding color weight parameter to obtain multiple products; the multiple products are summed to obtain a sum value; and the sum value, the second backlight intensity, and an adjustment coefficient are multiplied to obtain the estimated value, wherein the adjustment coefficient is related to the setting parameters of the light sensor.

7. The ambient light detection system of claim 5, wherein when the processing unit receives multiple consecutive estimates whose changes are all less than a preset value, it sends the current estimate to the subtractor to obtain the ambient light sensing value.

8. An ambient light detection method for an electronic device, the electronic device comprising a light-transmitting display sequentially displaying L images according to L pieces of image data during a sensing period, wherein each piece of image data comprises M first pixel color values ​​and a first backlight level, and L is a positive integer greater than or equal to 1, the ambient light detection method comprising the following steps: sensing ambient light through a light sensor to generate a first sensing value; obtaining a predicted value based on N×L first pixel color values ​​corresponding to N pixels in the display, N color weight parameters, and L first backlight levels, wherein N is a positive integer less than M and greater than 1; and subtracting the predicted value from the first sensing value to obtain an ambient light sensing value; wherein, This estimate is an estimate of the intensity of light from the display hitting the light sensor.

9. The ambient light detection method as described in claim 8, wherein the steps for obtaining the estimated value include: The color values ​​of the first pixel corresponding to the same pixel in the L image data are averaged to obtain N second pixel color values; The first backlight level of the L image data is averaged to obtain a second backlight level; the N second pixel color values ​​are converted into N pixel color intensity values, wherein one color weight parameter corresponds to one pixel color intensity value; the second backlight level is converted into a backlight intensity; the N pixel color intensity values ​​are multiplied by their corresponding color weight parameters to obtain multiple products; the multiple products are summed to obtain a total value. The estimated value is obtained by multiplying the sum, the backlight intensity, and an adjustment factor, wherein the adjustment factor is related to the setting parameters of the light sensor.

10. The ambient light detection method as described in claim 8, wherein the steps for obtaining the estimated value include: In each piece of image data, the N color values ​​of the first pixel corresponding to the N pixels are converted into N color intensity values ​​of the first pixel. The first pixel color intensity value corresponding to the same pixel is averaged to obtain N second pixel color intensity values, wherein one color weight parameter corresponds to one second pixel color intensity value; the first backlight level of the L image data is converted into L first backlight intensities; the L first backlight intensities are averaged to obtain a second backlight intensity; the N second pixel color intensity values ​​are multiplied by the corresponding color weight parameter to obtain multiple products; the multiple products are summed to obtain a sum value; and the sum value, the second backlight intensity, and an adjustment coefficient are multiplied to obtain the estimated value, wherein the adjustment coefficient is related to the setting parameters of the light sensor.

11. The ambient light detection method of claim 8, wherein the step of subtracting the estimated value from the first sensing value to obtain the ambient light sensing value includes subtracting the current estimated value from the first sensing value to obtain the ambient light sensing value when the changes in the estimated value obtained in multiple consecutive times are all less than a preset value.

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