Light frequency adaptive anti-stroboflash method and system for building intercom equipment

Abstract

The invention belongs to the field of building talkback, and particularly relates to a light frequency self-adaptive anti-stroboflash method and system for building talkback equipment, and the method comprises the following steps: S1, when the building talkback equipment is powered on to start or detects that ambient light becomes bright from dark, triggering an automatic frequency detection process, and entering the next step; and S2, high-frequency image acquisition and signal extraction. According to the invention, traditional indirect modes such as manual setting, GPS or IP geographic positioning and the like are abandoned, the image sensor of the building intercom device itself is creatively and directly used as a frequency detector, and the flicker frequency of the building intercom device is directly and accurately obtained by analyzing the brightness change of the environment light on the image. And a closed-loop self-adaptive control logic of'perception-decision-execution 'is established, so that the building intercom equipment has the intelligence of'self-adaptive' environment, and real plug and play is realized.

Description

Technical Field

[0001] This invention relates to the field of building intercom systems, and more particularly to a method and system for adaptive anti-flickering of light frequency in building intercom equipment. Background Technology

[0002] Currently, both the indoor and door units of building intercom systems have built-in cameras for video calls and monitoring. However, due to differences in AC power frequencies across different countries and regions globally, the flicker frequencies of artificial light sources also vary. The existing technology suffers from the following problems: 1. Manual setting mode: Most devices require users or installers to manually select the 50Hz or 60Hz anti-flicker mode in the system settings. This method is not user-friendly, and if the setting is incorrect, it will cause black scrolling stripes or flickering in the recorded video, which will seriously affect the visual effect. 2. Reliance on GPS or IP address: A few solutions attempt to infer the location through GPS or network IP address in order to set the frequency. However, this method will fail when the GPS signal is weak indoors, there is no network, or a VPN is used, and it cannot cope with scenarios such as carrying devices while traveling or changes in local power grid standards. To address the problems existing in the current technology, we propose a method and system for adaptive anti-flickering of lighting frequency for building intercom equipment. Summary of the Invention

[0003] This invention proposes a method and system for adaptive anti-flicker of lighting frequency in building intercom equipment, which solves the problems existing in the prior art.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A method for adaptive anti-flicker of light frequency for building intercom equipment includes the following steps: S1: When the building intercom device is powered on or detects that the ambient light has changed from dark to bright, it triggers the automatic frequency detection process and proceeds to the next step; S2: High-frequency image acquisition and signal extraction: The control logic module uses I... 2 The C bus sends a command to the image sensor to temporarily switch the image sensor to a working mode of 240fps and VGA resolution. The image sensor continuously acquires 60 frames of images at this high frame rate and transmits the image data to the frequency detection module in real time. S3: Frequency analysis, the specific steps of which are as follows: S301: The frequency detection module takes the center region of each frame of image transmitted by the image sensor to eliminate edge interference, calculates the average value of the brightness components of all pixels in the region, the brightness of the pixel is Y, and then arranges 60 consecutive brightness average values ​​in chronological order to form a brightness signal sequence Y[n] of length 60, where n = 0,1, 2, ..., 59; S302: The frequency detection module preprocesses the acquired luminance signal sequence Y[n]. The preprocessed signal is then subjected to a Fast Fourier Transform (FFT) to calculate the magnitude of the FFT result and obtain the power spectrum P[k] of the signal. S303: Find the maximum peak value other than 0Hz and its corresponding frequency index k_max in the power spectrum. Then, based on the sampling frequency and the number of FFT points (240Hz and 64 FFT points), calculate the actual frequency f_peak corresponding to the peak value using the formula f_peak = k_max * (240 / 64). S4: Logical decision-making and parameter adjustment, which specifically includes the following steps: S401: The control logic module receives the f_peak value; S402: The control logic module executes the judgment logic, which is as follows: If the value of f_peak is in the range of 95Hz to 110Hz, it is determined that the current power grid environment is 50Hz and the light flickering frequency is 100Hz. If the value of f_peak is in the range of 115Hz to 125Hz, it is determined that the current power grid environment is 60Hz and the light flickering frequency is 120Hz. S403: The control logic module generates control instructions based on the judgment result. The specific control instructions are as follows: If the frequency is determined to be 100Hz, the instruction is: SET_SHUTTER_SPEED(1 / 100); If the frequency is determined to be 120Hz, the instruction is: SET_SHUTTER_SPEED(1 / 120); S404: The image acquisition parameter adjustment module receives the control command from S403 and sets the electronic shutter speed of the image sensor to a fixed value through the image sensor's drive interface. At the same time, the control logic module switches the image sensor's working mode from high-speed acquisition mode back to the normal 1080P@30fps full HD call mode. At this time, the image sensor works at a fixed shutter speed that matches the light frequency. S5: Effect Verification and Continuous Monitoring: After the adjustment of S404 is completed, the operating system of the building intercom equipment starts a low-speed background monitoring task. This task wakes up once every minute and re-executes the automatic frequency detection process. If the frequency detected multiple times is consistent with the current setting, the original setting is maintained. If the frequency is detected to have changed, the shutter speed is automatically readjusted to achieve continuous self-adaptation.

[0005] Preferably, in step S1, the conditions for triggering the automatic frequency detection process are set to two, and triggering can be performed as long as either condition is met: Condition A: The building intercom system has completed a cold start or a warm start. Submission B: The ambient light sensor built into the building intercom system detected a significant increase in ambient light intensity within a short period of time, indicating that someone may have turned on the lights or the building intercom system may have been moved to a bright location.

[0006] Preferably, in S2, the 240fps and VGA resolution operating mode can provide sufficient time resolution to accurately capture high-frequency flicker of 100 / 120Hz.

[0007] Preferably, in step S302, the preprocessing of the luminance signal sequence Y[n] includes subtracting its DC component to highlight the AC fluctuation portion.

[0008] The present invention also proposes a light frequency adaptive anti-flicker system for building intercom equipment, including an image sensor, a frequency detection module, a control logic module and an image acquisition parameter adjustment module; The image sensor is connected to the frequency detection module and the image acquisition parameter adjustment module. The frequency detection module is connected to the image acquisition parameter adjustment module through the control logic module.

[0009] Preferably, the image sensor acquires the raw video stream under the control of the control logic module and sends it to the frequency detection module; The frequency detection module analyzes the changes in brightness or RGB channel values ​​of the image in real time from the video stream to detect the inherent flicker frequency of the ambient light. The control logic module generates control commands based on the detected ambient light flicker frequency and sends them to the image acquisition parameter adjustment module. The image acquisition parameter adjustment module receives control commands to dynamically adjust the parameters of the image sensor.

[0010] Compared with existing technologies, this invention abandons the traditional indirect methods such as manual settings, GPS or IP geolocation, and creatively uses the building intercom device's own image sensor as a "frequency detector". By analyzing the brightness changes caused by ambient light on the image, it directly and accurately obtains the flicker frequency and establishes a closed-loop adaptive control logic of "perception-decision-execution". This enables the building intercom device to have the intelligence of "self-adapting" to the environment and achieve true plug-and-play functionality. Attached Figure Description

[0011] Figure 1 This is a flowchart of an adaptive anti-flicker method for light frequency in building intercom equipment proposed in this invention; Figure 2 This is a block diagram of a light frequency adaptive anti-flicker system for building intercom equipment proposed in this invention. Detailed Implementation

[0012] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0013] Reference Figure 1 A method for adaptive anti-flicker of light frequency for building intercom equipment includes the following steps: S1: When the building intercom equipment powers on or detects that the ambient light has changed from dark to bright, it triggers the automatic frequency detection process and proceeds to the next step. There are two conditions for triggering the automatic frequency detection process, and it will be triggered as long as either condition is met: Condition A: The building intercom system has completed a cold start or a warm start. Submission B: The ambient light sensor built into the building intercom system detected a significant increase in ambient light intensity within a short period of time, indicating that someone may have turned on the lights or the building intercom system may have been moved to a bright location. S2: High-frequency image acquisition and signal extraction: The control logic module uses I... 2 The C bus sends a command to the image sensor to temporarily switch the image sensor to a 240fps and VGA resolution working mode. The 240fps and VGA resolution working mode can provide sufficient time resolution to accurately capture the high-frequency flicker of 100 / 120Hz. The image sensor continuously acquires 60 frames of images at this high frame rate and transmits the image data to the frequency detection module in real time. S3: Frequency analysis, the specific steps of which are as follows: S301: The frequency detection module takes the center region of each frame of image transmitted by the image sensor to eliminate edge interference, calculates the average value of the brightness components of all pixels in the region, the brightness of the pixel is Y, and then arranges 60 consecutive brightness average values ​​in chronological order to form a brightness signal sequence Y[n] of length 60, where n = 0,1, 2, ..., 59; S302: The frequency detection module preprocesses the acquired luminance signal sequence Y[n]. The preprocessing of the luminance signal sequence Y[n] includes subtracting its DC component to highlight the AC fluctuation part. The preprocessed signal is subjected to a fast Fourier transform to calculate the magnitude of the FFT result and obtain the power spectrum P[k] of the signal. S303: Find the maximum peak value other than 0Hz and its corresponding frequency index k_max in the power spectrum. Then, based on the sampling frequency and the number of FFT points (240Hz and 64 FFT points), calculate the actual frequency f_peak corresponding to the peak value using the formula f_peak = k_max * (240 / 64). S4: Logical decision-making and parameter adjustment, which specifically includes the following steps: S401: The control logic module receives the f_peak value; S402: The control logic module executes the judgment logic, which is as follows: If the value of f_peak is in the range of 95Hz to 110Hz, it is determined that the current power grid environment is 50Hz and the light flickering frequency is 100Hz. If the value of f_peak is in the range of 115Hz to 125Hz, it is determined that the current power grid environment is 60Hz and the light flickering frequency is 120Hz. S403: The control logic module generates control instructions based on the judgment result. The specific control instructions are as follows: If the frequency is determined to be 100Hz, the instruction is: SET_SHUTTER_SPEED(1 / 100); If the frequency is determined to be 120Hz, the instruction is: SET_SHUTTER_SPEED(1 / 120); S404: The image acquisition parameter adjustment module receives the control command from S403 and sets the electronic shutter speed of the image sensor to a fixed value through the image sensor's drive interface. At the same time, the control logic module switches the image sensor's working mode from high-speed acquisition mode back to the normal 1080P@30fps full HD call mode. At this time, the image sensor works at a fixed shutter speed that matches the light frequency. S5: Effect Verification and Continuous Monitoring: After the adjustment of S404 is completed, the operating system of the building intercom equipment starts a low-speed background monitoring task. This task wakes up once every minute and re-executes the automatic frequency detection process. If the frequency detected multiple times is consistent with the current setting, the original setting is maintained. If the frequency is detected to have changed, the shutter speed is automatically readjusted to achieve continuous self-adaptation. This embodiment abandons the traditional indirect methods such as manual settings, GPS or IP geolocation, and creatively uses the building intercom device's own image sensor as a "frequency detector". By analyzing the brightness changes caused by ambient light on the image, it directly and accurately obtains the flicker frequency and establishes a closed-loop adaptive control logic of "perception-decision-execution". This enables the building intercom device to have the intelligence to "self-adapt" to the environment and achieve true plug-and-play functionality.

[0014] Reference Figure 2 This embodiment also proposes a light frequency adaptive anti-flicker system for building intercom equipment, including an image sensor, a frequency detection module, a control logic module, and an image acquisition parameter adjustment module; The image sensor is connected to the frequency detection module and the image acquisition parameter adjustment module. The frequency detection module is connected to the image acquisition parameter adjustment module through the control logic module. The image sensor acquires raw video streams under the control of the control logic module and sends them to the frequency detection module; The frequency detection module analyzes the changes in brightness or RGB channel values ​​of the image in real time from the video stream to detect the inherent flicker frequency of the ambient light. The control logic module generates control commands based on the detected ambient light flicker frequency and sends them to the image acquisition parameter adjustment module. The image acquisition parameter adjustment module receives control commands to dynamically adjust the parameters of the image sensor.

[0015] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for adaptive anti-flicker lighting in building intercom equipment, characterized in that, Includes the following steps: S1: When the building intercom device is powered on or detects that the ambient light has changed from dark to bright, it triggers the automatic frequency detection process and proceeds to the next step; S2: High-frequency image acquisition and signal extraction: The control logic module uses I... 2 The C bus sends a command to the image sensor to temporarily switch the image sensor to a working mode of 240fps and VGA resolution. The image sensor continuously acquires 60 frames of images at this high frame rate and transmits the image data to the frequency detection module in real time. S3: Frequency analysis, the specific steps of which are as follows: S301: The frequency detection module takes the center region of each frame of image transmitted by the image sensor to eliminate edge interference, calculates the average value of the brightness components of all pixels in the region, the brightness of the pixel is Y, and then arranges 60 consecutive brightness average values ​​in chronological order to form a brightness signal sequence Y[n] of length 60, where n = 0, 1,2, ..., 59; S302: The frequency detection module preprocesses the acquired luminance signal sequence Y[n]. The preprocessed signal is then subjected to a Fast Fourier Transform (FFT) to calculate the magnitude of the FFT result and obtain the power spectrum P[k] of the signal. S303: Find the maximum peak value other than 0Hz and its corresponding frequency index k_max in the power spectrum. Then, based on the sampling frequency and the number of FFT points (240Hz and 64 FFT points), calculate the actual frequency f_peak corresponding to the peak value using the formula f_peak = k_max * (240 / 64). S4: Logical decision-making and parameter adjustment, which specifically includes the following steps: S401: The control logic module receives the f_peak value; S402: The control logic module executes the judgment logic, which is as follows: If the value of f_peak is in the range of 95Hz to 110Hz, it is determined that the current power grid environment is 50Hz and the light flickering frequency is 100Hz. If the value of f_peak is in the range of 115Hz to 125Hz, it is determined that the current power grid environment is 60Hz and the light flickering frequency is 120Hz. S403: The control logic module generates control instructions based on the judgment result. The specific control instructions are as follows: If the frequency is determined to be 100Hz, the instruction is: SET_SHUTTER_SPEED(1 / 100); If the frequency is determined to be 120Hz, the instruction is: SET_SHUTTER_SPEED(1 / 120); S404: The image acquisition parameter adjustment module receives the control command from S403 and sets the electronic shutter speed of the image sensor to a fixed value through the image sensor's drive interface. At the same time, the control logic module switches the image sensor's working mode from high-speed acquisition mode back to the normal 1080P@30fps full HD call mode. At this time, the image sensor works at a fixed shutter speed that matches the light frequency. S5: Effect Verification and Continuous Monitoring: After the adjustment of S404 is completed, the operating system of the building intercom equipment starts a low-speed background monitoring task. This task wakes up once every minute and re-executes the automatic frequency detection process. If the frequency detected multiple times is consistent with the current setting, the original setting is maintained. If the frequency is detected to have changed, the shutter speed is automatically readjusted to achieve continuous self-adaptation.

2. The method for adaptive anti-flicker lighting for building intercom equipment according to claim 1, characterized in that, In step S1, there are two conditions for triggering the automatic frequency detection process, and the process can be triggered as long as either condition is met: Condition A: The building intercom system has completed a cold start or a warm start. Submission B: The ambient light sensor built into the building intercom system detected a significant increase in ambient light intensity within a short period of time, indicating that someone may have turned on the lights or the building intercom system may have been moved to a bright location.

3. The method for adaptive anti-flicker lighting for building intercom equipment according to claim 1, characterized in that, In S2, the 240fps and VGA resolution operating modes provide sufficient time resolution to accurately capture high-frequency flicker of 100 / 120Hz.

4. The method for adaptive anti-flicker lighting for building intercom equipment according to claim 1, characterized in that, In step S302, the preprocessing of the luminance signal sequence Y[n] includes subtracting its DC component to highlight the AC fluctuation portion.

5. A light frequency adaptive anti-flicker system for building intercom equipment, used to perform the method according to any one of claims 1-4, characterized in that, It includes an image sensor, a frequency detection module, a control logic module, and an image acquisition parameter adjustment module; The image sensor is connected to the frequency detection module and the image acquisition parameter adjustment module. The frequency detection module is connected to the image acquisition parameter adjustment module through the control logic module.

6. A light frequency adaptive anti-flicker system for building intercom equipment according to claim 5, characterized in that, The image sensor acquires raw video streams under the control of the control logic module and sends them to the frequency detection module; The frequency detection module analyzes the changes in brightness or RGB channel values ​​of the image in real time from the video stream to detect the inherent flicker frequency of the ambient light. The control logic module generates control commands based on the detected ambient light flicker frequency and sends them to the image acquisition parameter adjustment module. The image acquisition parameter adjustment module receives control commands to dynamically adjust the parameters of the image sensor.

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