WO2018205235A1

WO2018205235A1 - Method for improving night vision distance and reducing power consumption, apparatus and system

Info

Publication number: WO2018205235A1
Application number: PCT/CN2017/084036
Authority: WO
Inventors: 任红军; 陈继健
Original assignee: 天彩电子（深圳）有限公司
Priority date: 2017-05-12
Filing date: 2017-05-12
Publication date: 2018-11-15

Abstract

A method for improving night vision distance and reducing power consumption, and an apparatus and a system. The method comprises: powering on and switching on a night vision function, and determining whether there is a shutter synchronisation function (S1); if so, then synchronising PWM signal output by means of a shutter signal and implementing infrared dimming on the basis of the outputted PWM signal (S2); if not, then analysing collected images in real-time by means of DSP and, on the basis of the exposure of the images, adjusting the duty cycle of the PWM signal and performing infrared dimming on the basis of the outputted PWM (S3). The present method uses PWM to dim an infrared LED and incorporates DSP to analyse images, performing real-time adjustment of the PWM on the basis of the analysis results, and ensuring the light compensation for the exposure requirements of the image sensor, such that the imaging effects achieve a high quality and the power-on time of the infrared light compensation is reduced, reducing power consumption.

Description

Method, device and system for increasing night vision distance and reducing power consumption

Technical field

The present invention relates to the field of image processing technology, and more particularly to a method and apparatus and system for improving night vision distance and reducing power consumption.

Background technique

With the improvement of people's living standards and the awareness of safety precautions, video surveillance equipment, video doorbells, security cameras and other shooting equipment with camera and camera functions are increasingly used by people. In this type of shooting device, in order to enable the shooting device to capture a better video picture under different ambient brightness conditions, infrared fill light is generally used as a supplementary light source at night and in dim light conditions. At the same time, in order to enable the infrared fill light to be turned on at night and in dim light conditions, a photometric device is usually mounted on the photographing device to measure the current visible light illumination, and provide a reference for the infrared fill light to be turned on and off.

The currently available infrared fill light technology on the market includes three methods. The first method is to use a photoresistor to detect the brightness and darkness of the ambient light to trigger the switching of the infrared LED fill light. The detection sensitivity of the mode is not high; the second method: using the image Sensor metering technology, trigger control switch infrared LED fill light, although it can be done to switch between day and night scenes, so that the image quality can achieve good results in day and night scenes, but in the dark and dark scenes, due to infrared The LED is always on, which will increase the power consumption of the camera. This is a big challenge for some battery-powered night vision camera equipment and video surveillance equipment. Mode 3: PWM (Pulse) Width Modulation) The technology of wave modulation infrared LED driver has achieved the purpose of dimming and reducing power consumption, but the adjustment of PWM parameters (duty cycle, frequency) is based on the brightness of the external ambient light, which cannot be accurately based on the image sensor. 1 The exposure needs to be adjusted.

Chinese Patent No. 201110089768.7 discloses an infrared product video analysis dimming VAAL implementation method, the circuit used in the method comprises a microprocessor, the microprocessor is connected to the camera through an on-chip video A/D circuit interface, and the microprocessor is connected by an on-chip PWM. Infrared lamp circuit; the microprocessor is connected to the photosensor; and the following steps are included: intelligently analyzing the captured video image through the DSP, and controlling the output power and the on mode of the infrared lamp, thereby achieving the purpose of improving the video effect and saving energy, Infrared product video analysis dimming VAAL can reduce the infrared power when there is no moving target, and increase the infrared power when the moving target appears, which can reduce the power consumption of the whole machine, effectively extend the service life of infrared, and can also be used when moving targets , to achieve a good night vision effect.

However, in the above patents, all video or images must be analyzed by DSP, and the light can be complemented according to the analysis of the exposure rate, and the efficiency is relatively low.

Therefore, it is necessary to design a method for increasing the night vision distance and reducing the power consumption, thereby reducing the time for the infrared fill light to be energized, thereby reducing the heat generated by the illumination, reducing the power consumption, and improving the clear imaging effect of the night view painting. .

Summary of the invention

It is an object of the present invention to overcome the deficiencies of the prior art and to provide a method and apparatus for increasing night vision distance and reducing power consumption.

To achieve the above object, the present invention adopts the following technical solutions: a method for improving night vision distance and reducing power consumption, the method comprising:

S1, power on and turn on the night vision function to determine whether there is a shutter synchronization function. If there is a shutter synchronization function, perform step S2, or if there is no shutter synchronization function, proceed to step S3;

S2, synchronizing the PWM IR output through the shutter signal, and performing infrared dimming according to the output PWM IR;

S3, real-time analysis of the acquired image by DSP, adjusting PWM according to the exposure of the image The duty cycle of the duty modulation value, and infrared dimming according to the PWM duty of the output.

The further technical solution is: synchronous PWM IR output through the shutter signal, according to the output PWM IR performs infrared dimming steps, including the following specific steps:

S21. Determine whether the infrared lamp driver is in the off period. If the infrared lamp driver is in the off period, proceed to step S22, or if the infrared lamp driver is not in the off period, proceed to step S23;

S22. Maintain the original output state of the PWM IR.

S23. Synchronous on/off IR transmission.

A further technical solution is: the step of synchronously turning on/off IR transmission, comprising the following specific steps:

S231, determining whether the shutter is in the closed state, if the shutter is in the closed state, proceeding to step S232, or if the shutter is not in the closed state, proceeding to step S233;

S232, PWM IR is a low pulse width, and the infrared light is turned off;

S233, PWM IR is a high pulse width, and the infrared light is turned on.

The further technical solution is: analyzing the acquired image in real time through the DSP, and adjusting the PWM according to the exposure of the image. The duty cycle of the duty modulation value and the infrared dimming step according to the PWM duty of the output, including the following specific steps:

S31. Determine whether the exposure of each frame of the image meets the set requirement. If the exposure of each frame of the image meets the set requirement, proceed to step S32, or if the exposure of each frame of the image is not If the requirements of the setting are met, proceed to step S33;

S32, maintaining the number of pulses of the PWM IR modulation value, performing infrared dimming;

S33. Adjusting the PWM according to the exposure distribution of the image during a period in which the infrared driver is turned on. The duty ratio of the duty modulation value is used for infrared dimming.

A further technical solution is: adjusting the duty ratio of the PWM modulation value according to the exposure distribution of the image during the period in which the infrared driver is turned on, and performing the infrared dimming step, including the following specific steps:

S331, pushing forward the leading edge of the number of pulses added before the PWM IR modulation value;

S332. Push back the trailing edge of the number of pulses added after the PWM IR modulation value.

The present invention also provides an apparatus for improving night vision distance and reducing power consumption, including an image sensor, a digital signal processor, and an infrared lamp driver; the image sensor and the infrared lamp driver are respectively connected to a digital signal processor; When the image sensor has a shutter synchronization function, the image sensor synchronizes the PWM of the digital signal processor through the shutter signal IR output, according to the PWM output of the digital signal processor The IR driving infrared lamp driver performs infrared dimming; when the image sensor does not have the shutter synchronization function, the image sensor sends the image to the digital signal processor, and the acquired image is analyzed in real time through the digital signal processor, according to the exposure of the image Adjust the PWM of the digital signal processor The duty cycle of the duty modulation value, and according to the PWM duty of the output, the infrared lamp driver is driven to perform infrared dimming.

The present invention also provides a system for improving night vision distance and reducing power consumption, including a shutter synchronization determination unit, a shutter processing unit, and a non-shutter processing unit;

The shutter synchronization determining unit is configured to determine whether a shutter synchronization function exists;

The shutter processing unit is configured to synchronously PWM IR output through a shutter signal, and perform infrared dimming according to the output PWM IR;

The non-shutter processing unit is configured to analyze the acquired image in real time through the DSP, and adjust the PWM according to the exposure of the image. The duty cycle of the duty modulation value, and infrared dimming according to the PWM duty of the output.

A further technical solution is that the shutter processing unit includes a driver judging module, an original state maintaining module, and a synchronous transmitting module;

The driver determining module is configured to determine whether the infrared light driver is in a closing period;

The original state maintaining module is configured to maintain an original output state of the PWM IR if the infrared lamp driver is in a off period;

The synchronous transmitting module is configured to synchronously turn on/off IR transmission if the infrared light driver is not in the off period.

A further technical solution is that the synchronous transmitting module includes a shutter state determining submodule and a processing submodule;

The shutter state determining submodule is configured to determine whether the shutter is in a closed state;

The processing submodule is configured to if the shutter is in a closed state, PWM IR is a low pulse width, the IR light is off, or, if the shutter is not off, PWM IR is a high pulse width and the IR light is on.

A further technical solution is that the non-shutter processing unit includes an exposure degree judging module and a duty ratio processing module;

The exposure degree determining module is configured to determine whether an exposure of each frame of the image meets a set requirement;

The duty ratio processing module is configured to maintain PWM if an exposure of each frame of the image meets a set requirement The duty ratio of the duty modulation value is infrared dimming, or if the exposure of each frame of the image does not meet the set requirement, the exposure distribution of the image is adjusted during the period in which the infrared driver is turned on. PWM The duty ratio of the duty modulation value is used for infrared dimming.

The invention has the beneficial effects compared with the prior art: the method for improving the night vision distance and reducing the power consumption of the invention, adopting PWM and DSP combined manner, dimming the infrared LED by using PWM, and combining with the DSP pair The image is analyzed, and the PWM is adjusted in real time according to the analysis result, thereby further reducing the power consumption, and at the same time ensuring the required light filling requirement of the image sensor exposure, so that the imaging effect reaches a high quality, and the time for reducing the infrared fill light is realized, thereby Reduces the heat generated by the illuminating, reduces power consumption, and improves the clear imaging effect of night view painting.

The invention is further described below in conjunction with the drawings and specific embodiments.

DRAWINGS

1 is a flowchart of a method for increasing night vision distance and reducing power consumption according to an embodiment of the present invention;

2 is a specific flowchart of synchronous PWM output by a shutter signal according to an embodiment of the present invention;

3 is a schematic diagram of signal waveforms of a synchronous PWM output through a shutter signal according to an embodiment of the present invention;

4 is a specific flowchart of synchronous on/off IR transmission according to an embodiment of the present invention;

FIG. 5 is a specific flowchart of adjusting a captured image by a DSP in real time according to an embodiment of the present invention and adjusting a duty ratio of a PWM modulation value according to an exposure of the image;

6 is a schematic diagram of a signal waveform of a DSP that analyzes a captured image in real time according to an embodiment of the present invention and adjusts a duty ratio of a PWM modulation value according to an exposure of the image;

FIG. 7 is a specific flowchart of adjusting a duty ratio of a PWM modulation value according to an embodiment of the present invention;

FIG. 8 is a signal flow diagram of an apparatus for improving night vision distance and reducing power consumption according to an embodiment of the present invention; FIG.

FIG. 9 is a structural block diagram of an apparatus for improving night vision distance and reducing power consumption according to an embodiment of the present invention;

FIG. 10 is a structural block diagram of a system for improving night vision distance and reducing power consumption according to an embodiment of the present invention; FIG.

11 is a structural block diagram of a shutter processing unit according to an embodiment of the present invention;

FIG. 12 is a structural block diagram of a synchronous transmitting module according to an embodiment of the present invention;

FIG. 13 is a structural block diagram of a non-shutter processing unit according to an embodiment of the present invention.

detailed description

In order to more fully understand the technical content of the present invention, the technical solutions of the present invention are further described and illustrated in conjunction with the specific embodiments, but are not limited thereto.

As shown in the specific embodiments shown in FIG. 1 to FIG. 13 , the method for improving the night vision distance and reducing the power consumption provided by the embodiment can be applied to the video monitoring device to reduce the time for the infrared fill light to be energized, thereby reducing the illumination. The heat generated reduces power consumption and enhances the clear imaging of night view painting.

This embodiment provides a method for increasing night vision distance and reducing power consumption, the method comprising:

S1, power on and turn on the night vision function, determine whether there is a shutter synchronization function, if there is a shutter synchronization function, proceed to step S2, or if there is no shutter synchronization function, proceed to step S3;

The above S1 step is judged to adopt different infrared dimming modes for different image sensors 1.

Further, in the above step S2, the PWM IR output is synchronized by the shutter signal, according to the output PWM IR performs infrared dimming steps, including the following specific steps:

S21, determining whether the infrared lamp driver 3 is in the off period, if the infrared lamp driver 3 is in the off period, proceeding to step S22, or if the infrared lamp driver 3 is not in the off period, proceeding to step S23;

S22. Maintain the original output state of the PWM IR.

S23. Synchronous on/off IR transmission.

For the above step S21, the infrared dimming is performed only during the period when the infrared lamp driver 3 is turned on. If the infrared lamp driver 3 is not turned on, the infrared dimming cannot be performed, and only the original output state of the PWM can be maintained.

In addition, for the step S23, the step of synchronously turning on/off the IR transmission includes the following specific steps:

S232, PWM IR is a low pulse width, and the infrared light is turned off;

S233, PWM IR is a high pulse width, and the infrared light is turned on.

The digital processor outputs a high pulse trigger signal to the image sensor 1TRIGGER pin. When the image sensor 1 detects that the TRIGGER pin has been turned on, the shutter exposure time starts, and then the image sensor 1 starts reading the first frame of image data until End.

After the shutter signal is given, the digital signal processor 2 synchronously outputs the PWM pulse width signal to control the infrared LED driver to be turned on and off. When the shutter trigger signal is synchronized, the IR emission is turned on/off, that is, when the shutter is closed, the PWM is turned off by the Low infrared light, and when the shutter is opened, the PWM is turned on by the High infrared light.

Using PWM The purpose of the IR output pulse width modulation signal is to reduce the overall average power consumption. As shown in Figure 2, the duty ratio is set to 50%, and the power consumption can be effectively reduced by 50%.

The modulation of the PWM is to synchronize the shutter open time of the frame; specifically, during the PWM on period, when the shutter is required to be turned on, the PWM is High, and when the shutter is closed, the PWM is Low, so that the image quality can be changed without changing the image quality. The power consumption is further reduced, so that the power consumption of the transmission can be actually reflected back to the image sensor 1 and detected.

The shutter signal is used to synchronize the control method of the PWM output of the main control chip, and the image sensor 1 shutter signal and the synchronous PWM pulse width modulation signal are used to control the infrared LED switch state, thereby further reducing power consumption and improving imaging effect; For the night vision camera of the battery, this technology can reduce the time of infrared fill light energization, thereby reducing the heat generated by long-time illumination, and can effectively reduce power consumption and ensure the shooting effect of the camera, and prolong the operating life of the device. .

For the S3 step, there is no shutter synchronization function for the image sensor 1. Under this condition, when the PWM is a period of low pulse width, if the image of the image sensor 1 is not transmitted, the image will definitely exist on one side. In the case of dark side, it is necessary to analyze the acquired image in real time through the DSP, adjust the duty ratio of the PWM modulation value according to the exposure of the image, and perform infrared dimming according to the output PWM.

In the step S3, the acquired image is analyzed in real time by the DSP, and the PWM is adjusted according to the exposure of the image. The duty cycle of the duty modulation value, and infrared dimming according to the PWM duty of the output, including the following specific steps:

In the above step S31, the step of determining whether the exposure of each frame of the image meets the set requirement is to select an image in which the same frame image is exposed to light and dark unevenness, and infrared dimming is performed on such image.

When there is no image in which the same frame image is exposed to light and dark unevenness, the duty ratio of the PWM modulation value is maintained, and infrared dimming is performed.

When an image in which the same frame image is exposed to light and dark unevenness occurs, the duty ratio of the PWM modulation value is adjusted according to the exposure distribution of the image during the period in which the infrared driver is turned on, and infrared dimming is performed.

For the step S33, during the period in which the infrared driver is turned on, the duty ratio of the PWM modulation value is adjusted according to the exposure distribution of the image, and infrared dimming is performed, including the following specific steps:

In the above step S331, the leading edge of the duty ratio of the PWM modulation value is pushed forward until the dark area is reduced to an acceptable brightness or a dark area.

In the above step S332, the trailing edge of the duty ratio of the PWM modulation value is pushed backward, as long as a dark area does not appear below, ensuring that the front and rear edges can obtain an image whose exposure meets the set requirement, thereby improving the night vision effect.

The PWM method can reduce the time of infrared fill light energization, thereby reducing the heat generated by the illumination, reducing the power consumption, and prolonging the operating life of the device;

The use of DSP to analyze images in real time improves the image clarity of images obtained in dark environments.

The above method for improving night vision distance and reducing power consumption adopts PWM and DSP combination method to dim the infrared LED by PWM, and combines the DSP to analyze the image, and adjusts the PWM in real time according to the analysis result. Further reducing the power consumption, while ensuring the required light filling requirement of the image sensor 1 to achieve high quality of the imaging effect, reducing the time for the infrared fill light to be energized, thereby reducing the heat generated by the light, reducing the power consumption, and improving the night. The clear image of the view is drawn.

As shown in FIG. 8 to FIG. 9, the present embodiment provides an apparatus for improving night vision distance and reducing power consumption, including an image sensor 1, a digital signal processor 2, and an infrared lamp driver 3; an image sensor 1 and the infrared The lamp driver 3 is respectively connected to the digital signal processor 2; when the image sensor 1 has a shutter synchronization function, the image sensor 1 synchronizes the PWM of the digital signal processor 2 by the shutter signal IR output, according to the PWM output of digital signal processor 2 The IR driving infrared lamp driver 3 performs infrared dimming; when the image sensor 1 does not have a shutter synchronization function, the image sensor 1 transmits an image to the digital signal processor 2, and the acquired image is analyzed in real time by the digital signal processor 2, according to the Image exposure adjustment PWM of digital signal processor 2 The duty ratio of the duty modulation value, and according to the PWM duty of the output, drives the infrared lamp driver 3 to perform infrared dimming.

The above device for improving night vision distance and reducing power consumption adopts PWM by means of whether the image sensor 1 has a shutter synchronization function, and combined with the PWM outputted by the digital signal processor 2 and the DSP combined by the digital signal processor 2 The infrared LED is dimmed, and the image is analyzed by combining with the DSP, and the PWM is adjusted in real time according to the analysis result, thereby further reducing the power consumption, and ensuring the required light filling requirement of the image sensor 1 to achieve high imaging effect. The quality can reduce the time of infrared fill light energization, thereby reducing the heat generated by the illumination, reducing the power consumption, and improving the clear imaging effect of the night view painting.

As shown in FIG. 10, a system for increasing night vision distance and reducing power consumption includes a shutter synchronization determination unit 10, a shutter processing unit 20, and a non-shutter processing unit 30.

The shutter synchronization determining unit 10 is configured to determine whether there is a shutter synchronization function.

The shutter processing unit 20 is configured to synchronize the PWM IR output through the shutter signal, and perform infrared dimming according to the output PWM IR.

The non-shutter processing unit 30 is configured to analyze the acquired image in real time through the DSP, and adjust the PWM according to the exposure of the image. The duty cycle of the duty modulation value, and infrared dimming according to the PWM duty of the output.

The shutter processing unit 20 described above includes a driver judging module 21, an original state holding module 22, and a sync transmitting module 23.

The driver judging module 21 is configured to judge whether the infrared lamp driver 3 is in an off period.

The original state maintaining module 22 is configured to maintain the original output state of the PWM IR if the infrared lamp driver 3 is in the off period.

The synchronous transmitting module 23 is configured to synchronously turn on/off the IR transmission if the infrared light driver 3 is not in the off period.

The driver judging module 21 is arranged to perform infrared dimming only when the infrared lamp driver 3 is turned on. If the infrared lamp driver 3 is not turned on, infrared dimming cannot be performed, and only the original output state of the PWM can be maintained.

The synchronous transmission module 23 includes a shutter state determination sub-module 231 and a processing sub-module 232.

The shutter state determining sub-module 231 is configured to determine whether the shutter is in a closed state.

The processing sub-module 232 is configured to: if the shutter is in a closed state, the PWM IR is a low pulse width, the IR light is off, or, if the shutter is not off, PWM IR is a high pulse width and the IR light is on.

After the shutter signal is given, the digital signal processor 2 synchronously outputs the PWM pulse width signal to control the infrared LED driver to be turned on and off. When the processing sub-module 232 has a shutter trigger signal, the IR emission is synchronously turned on/off, that is, when the shutter is closed, the PWM is turned off by the Low infrared light, and when the shutter is opened, the PWM is turned on by the High infrared light.

The purpose of using PWM output pulse width modulation signal is to reduce the average power consumption. As shown in Figure 2, the duty ratio is set to 50%, and the power consumption can be effectively reduced by 50%.

The shutter processing unit 20 de-synchronizes the master chip end PWM through the shutter signal IR output control method by using image sensor 1 shutter signal and synchronous PWM IR pulse width modulation signal to control the status of infrared LED switch, further reduce power consumption and improve imaging effect; for night vision camera with built-in battery, this technology can reduce the time of infrared fill light, thus reducing the long time The heat generated by the illumination can effectively reduce the power consumption and ensure the shooting effect of the camera, and prolong the operating life of the device.

The non-shutter processing unit 30 includes an exposure degree determination module 31 and a duty ratio processing module 32.

The exposure level determining module 31 is configured to determine whether the exposure of each frame of the image meets the set requirement.

The duty ratio processing module 32 is configured to maintain the PWM if the exposure of each frame of the image meets the set requirement The duty ratio of the duty modulation value is infrared dimming, or if the exposure of each frame of the image does not meet the set requirement, the exposure distribution of the image is adjusted during the period in which the infrared driver is turned on. PWM The duty ratio of the duty modulation value is used for infrared dimming.

In the case where the image sensor 1 does not have a shutter synchronization function, under such conditions, when the PWM is in a period of low pulse width, if the image of the image sensor 1 is not transmitted, the image at this time will definitely be bright on one side. In other cases, the acquired image needs to be analyzed by the non-shutter processing unit 30 described above through the DSP in real time, the duty ratio of the PWM modulation value is adjusted according to the exposure of the image, and infrared dimming is performed according to the output PWM.

The exposure degree judging module 31 described above is for selecting an image in which the same frame image is exposed to light and dark unevenness, and infrared dimming is performed on such an image.

When there is no image in which the same frame image is exposed to light and dark unevenness, the duty ratio processing module 32 maintains the duty ratio of the PWM modulation value to perform infrared dimming.

When an image of the same frame image is exposed to light and dark unevenness, the duty ratio processing module 32 adjusts the duty ratio of the PWM modulation value according to the exposure distribution of the image during the period in which the infrared driver is turned on. Infrared dimming.

The duty cycle processing module 32 described above pushes the leading edge of the duty cycle of the PWM modulation value forward during the period in which the infrared driver is turned on until the dark area is reduced to an acceptable brightness or a dark area. The trailing edge of the duty cycle of the PWM modulation value is pushed back, as long as the dark area does not appear below, ensuring that the front and rear edges can obtain an image with the exposure meeting the set requirements, thereby improving the night vision effect.

The above system for improving night vision distance and reducing power consumption adopts PWM and DSP combination method to dim the infrared LED by PWM, and combines the DSP to analyze the image, and adjusts the PWM in real time according to the analysis result. Further reducing the power consumption, while ensuring the required light filling requirement of the image sensor 1 to achieve high quality of the imaging effect, reducing the time for the infrared fill light to be energized, thereby reducing the heat generated by the light, reducing the power consumption, and improving the night. The clear image of the view is drawn.

The above technical description of the present invention is further described by way of example only, and is not to be understood by the reader, but the embodiments of the present invention are not limited thereto, and any technology extending or re-creating according to the present invention is subject to the present invention. protection of. The scope of the invention is defined by the claims.

Claims

A method for increasing night vision distance and reducing power consumption, characterized in that the method comprises:

S1, power on and turn on the night vision function to determine whether there is a shutter synchronization function. If there is a shutter synchronization function, perform step S2, or if there is no shutter synchronization function, proceed to step S3;

S2, synchronizing the PWM IR output through the shutter signal, and performing infrared dimming according to the output PWM IR;

S3, real-time analysis of the acquired image by the DSP, adjusting the duty ratio of the PWM duty modulation value according to the exposure of the image, and according to the output PWM Duty for infrared dimming.
The method for increasing night vision distance and reducing power consumption according to claim 1, wherein the PWM signal is synchronized by a shutter signal, and the PWM according to the output IR performs infrared dimming steps, including the following specific steps:

S21. Determine whether the infrared lamp driver is in the off period. If the infrared lamp driver is in the off period, proceed to step S22, or if the infrared lamp driver is not in the off period, proceed to step S23;

S22. Maintain the original output state of the PWM IR.

S23. Synchronous on/off IR transmission.
The method for increasing night vision distance and reducing power consumption according to claim 2, wherein the step of synchronously turning on/off IR transmission comprises the following specific steps:

S231, determining whether the shutter is in the closed state, if the shutter is in the closed state, proceeding to step S232, or if the shutter is not in the closed state, proceeding to step S233;

S232, PWM IR is a low pulse width, and the infrared light is turned off;

S233, PWM IR is a high pulse width, and the infrared light is turned on.
The method for improving night vision distance and reducing power consumption according to any one of claims 1 to 3, characterized in that the acquired image is analyzed in real time by the DSP, and the PWM is adjusted according to the exposure of the image. The duty cycle of the duty modulation value and the infrared dimming step according to the PWM duty of the output, including the following specific steps:

S31. Determine whether the exposure of each frame of the image meets the set requirement. If the exposure of each frame of the image meets the set requirement, proceed to step S32, or if the exposure of each frame of the image is not If the requirements of the setting are met, proceed to step S33;

S32, maintaining the number of pulses of the PWM IR modulation value, performing infrared dimming;

S33. Adjusting the PWM according to the exposure distribution of the image during a period in which the infrared driver is turned on. The duty ratio of the duty modulation value is used for infrared dimming.
The method for increasing night vision distance and reducing power consumption according to claim 4, wherein the duty ratio of the PWM modulation value is adjusted according to the exposure distribution of the image during a period in which the infrared driver is turned on , the step of performing infrared dimming, including the following specific steps:

S331, pushing forward the leading edge of the number of pulses added before the PWM IR modulation value;

S332. Push back the trailing edge of the number of pulses added after the PWM IR modulation value.
An apparatus for improving night vision distance and reducing power consumption, comprising: an image sensor, a digital signal processor, and an infrared lamp driver; wherein the image sensor and the infrared lamp driver are respectively connected to a digital signal processor; When the sensor has a shutter synchronization function, the image sensor synchronizes the PWM of the digital signal processor through the shutter signal IR output, according to the PWM output of the digital signal processor The IR driving infrared lamp driver performs infrared dimming; when the image sensor does not have the shutter synchronization function, the image sensor sends the image to the digital signal processor, and the acquired image is analyzed in real time through the digital signal processor, according to the exposure of the image Adjust the PWM of the digital signal processor The duty cycle of the duty modulation value, and according to the PWM duty of the output, the infrared lamp driver is driven to perform infrared dimming.
A system for improving night vision distance and reducing power consumption, comprising: a shutter synchronization determination unit, a shutter processing unit, and a non-shutter processing unit;

The shutter synchronization determining unit is configured to determine whether a shutter synchronization function exists;

The shutter processing unit is configured to synchronously PWM IR output through a shutter signal, and perform infrared dimming according to the output PWM IR;

The non-shutter processing unit is configured to analyze the acquired image in real time through the DSP, and adjust the PWM according to the exposure of the image. The duty cycle of the duty modulation value, and infrared dimming according to the PWM duty of the output.
The system for improving night vision distance and reducing power consumption according to claim 7, wherein the shutter processing unit comprises a driver judging module, an original state maintaining module, and a synchronous transmitting module;

The driver determining module is configured to determine whether the infrared light driver is in a closing period;

The original state maintaining module is configured to maintain an original output state of the PWM IR if the infrared lamp driver is in a off period;

The synchronous transmitting module is configured to synchronously turn on/off IR transmission if the infrared light driver is not in the off period.
The system for improving night vision distance and reducing power consumption according to claim 8, wherein the synchronous transmitting module comprises a shutter state determining sub-module and a processing sub-module;

The shutter state determining submodule is configured to determine whether the shutter is in a closed state;

The processing sub-module is configured to: if the shutter is in a closed state, the PWM IR is a low pulse width, the infrared light is turned off, or, if the shutter is not in a closed state, the PWM IR is a high pulse width and the IR light is on.
The system for improving night vision distance and reducing power consumption according to claim 9, wherein the non-shutter processing unit comprises an exposure degree judging module and a duty ratio processing module;

The exposure degree determining module is configured to determine whether an exposure of each frame of the image meets a set requirement;

The duty ratio processing module is configured to maintain PWM if an exposure of each frame of the image meets a set requirement The duty ratio of the duty modulation value is infrared dimming, or if the exposure of each frame of the image does not meet the set requirement, the exposure distribution of the image is adjusted during the period in which the infrared driver is turned on. PWM The duty ratio of the duty modulation value is used for infrared dimming.