CN103561203A - Automatic focusing high-definition camera based on CPLD and MCU - Google Patents

Automatic focusing high-definition camera based on CPLD and MCU Download PDF

Info

Publication number
CN103561203A
CN103561203A CN201310558097.3A CN201310558097A CN103561203A CN 103561203 A CN103561203 A CN 103561203A CN 201310558097 A CN201310558097 A CN 201310558097A CN 103561203 A CN103561203 A CN 103561203A
Authority
CN
China
Prior art keywords
mcu
cpld
focus
definition camera
camera based
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN201310558097.3A
Other languages
Chinese (zh)
Other versions
CN103561203B (en
Inventor
李君桥
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
WELLTRANS O&E TECHNOLOGIES Co Ltd
Original Assignee
WELLTRANS O&E TECHNOLOGIES Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by WELLTRANS O&E TECHNOLOGIES Co Ltd filed Critical WELLTRANS O&E TECHNOLOGIES Co Ltd
Priority to CN201310558097.3A priority Critical patent/CN103561203B/en
Publication of CN103561203A publication Critical patent/CN103561203A/en
Application granted granted Critical
Publication of CN103561203B publication Critical patent/CN103561203B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Landscapes

  • Automatic Focus Adjustment (AREA)
  • Studio Devices (AREA)

Abstract

The invention belongs to the technical field of cameras, and provides an automatic focusing high-definition camera based on a CPLD and a MCU. The camera comprises a video processing chip capable of outputting standard digital video signals and an electric lens drive assembly. The camera further comprises the CPLD and the MCU, wherein the CPLD carries out brightness extraction and focusing evaluation function calculation on the standard digital video signals output by the video processing chip and outputs a focusing evaluation function value; the MCU calculates in a hill-climbing search method according to the focusing evaluation function value and outputs a motor control signal. The electric lens drive assembly controls a focusing motor to complete automatic focusing according to the motor control signal. By means of characteristics of the CPLD and the MCU, advantages of components are effectively made use of to carry out task allocation and resource integration, the automatic focusing function which is stable, reliable, high in sensitivity and low in time delay characteristic is achieved, and compared with an existing automatic focusing technique, the camera can obviously reduce material cost.

Description

A kind of automatic focus high-definition camera based on CPLD and MCU
Technical field
The invention belongs to CCTV camera technical field, relate in particular to a kind of high-definition camera based on CPLD and MCU.Described high-definition camera can be realized fast automatic focusing function.
Background technology
The rich meeting of Shenzhen in 2010 peace, numerous security device manufacturer has released high-definition video monitoring video camera one after another, thereby has formally opened the high-definition video monitoring epoch.From " visible " to " seeing clearly ", high-definition video monitoring is by digitlization, networking technology, market approval and favor have been obtained rapidly, according to statistics, nowadays high-definition monitoring equipment Market share reaches 56%, surpassed the traditional analog video camera market share, high-definition camera is just more and more being applied to the protection and monitor field such as airport, road, transportation, port and pier, frontier inspection port, safe city.
The high-definition camera in general camera lens kind of adapted can be divided into: fixed focus lens, manual zoom lens, motorized zoom lens etc.Wherein during adapted motorized zoom lens, video camera need be supported Zoom control, focus control and the control of diaphragm of motorized zoom lens.Zoom control and the control of diaphragm be technology maturation comparatively speaking, and research and development are not difficult.But focus control, has implemented no small technical difficulty.
By FPGA, realizing automatic focus is current a kind of conventional this scheme, first with analog to digital converter, video is sampled, digital video data after pattern sampling inputs to FPGA and does video filtering, brightness extraction, automatic focus evaluation function computer and the realization of automatic focus hill-climbing algorithm, whole automatic focus is all realized by FPGA, therefore this scheme is higher for FPGA performance requirement, realizes at least 60 yuans of hardware costs.
Summary of the invention
In view of the above problems, the object of the present invention is to provide a kind of automatic focus high-definition camera based on CPLD and MCU, be intended to solve the existing higher technical problem of cost that realizes automatic focus scheme by FPGA.
The present invention realizes like this, the described automatic focus high-definition camera based on CPLD and MCU, the video frequency processing chip and the motor-driven lens driven unit that comprise exportable standard digital vision signal, described video camera also comprises CPLD and MCU, the standard digital vision signal of described video frequency processing chip output is carried out to brightness extraction to described CPLD and autofocus evaluation function calculates, output autofocus evaluation function value, described MCU carries out search by hill climbing algorithm according to described focus function evaluation of estimate and calculates output motor control signal, described motor-driven lens driven unit is controlled focus motor according to described motor control signal and is completed automatic focus.
The invention has the beneficial effects as follows: the present invention adopts CPLD and MCU to replace FPGA to complete auto-focus function, CPLD time delay is little, parallel data disposal ability is strong, can realize high-speed video data calculation process, in the present invention, using it for brightness extraction and autofocus evaluation function calculates, MCU has significant advantage aspect the single-threaded calculation process of complexity, in the present invention, used search by hill climbing algorithm to calculate, obtain the best focus position of camera lens, the present invention utilizes CPLD and MCU feature separately, effectively performance device intrinsic advantage is carried out task distribution and resource consolidation, can realize reliable and stable, high sensitivity, the auto-focus function of low delay character, compare with existing employing FPGA scheme, can obviously reduce Material Cost.
Accompanying drawing explanation
Fig. 1 is the structure chart of the automatic focus high-definition camera based on CPLD and MCU that provides of the embodiment of the present invention;
Fig. 2 is the CPLD block diagram that the embodiment of the present invention provides;
Fig. 3 is the BT.656 image line output timing diagram of the pal mode that provides of the embodiment of the present invention;
Fig. 4 is the MCU block diagram that the embodiment of the present invention provides;
Fig. 5 is autofocus evaluation function value and the motor stepping graph of relation that the embodiment of the present invention provides;
Fig. 6 is the search by hill climbing algorithm schematic diagram that the embodiment of the present invention provides.
Embodiment
In order to make object of the present invention, technical scheme and advantage clearer, below in conjunction with drawings and Examples, the present invention is further elaborated.Should be appreciated that specific embodiment described herein, only in order to explain the present invention, is not intended to limit the present invention.
For technical solutions according to the invention are described, below by specific embodiment, describe.
Fig. 1 shows the structure of the automatic focus high-definition camera based on CPLD and MCU that the embodiment of the present invention provides, and only shows for convenience of explanation the part relevant to the embodiment of the present invention.
The automatic focus high-definition camera based on CPLD and MCU that the present embodiment provides comprises video frequency processing chip 1 and the motor-driven lens driven unit 4 of exportable standard digital vision signal, described video camera also comprises field programmable logic device 2(CPLD) and microprocessor 3(MCU), described video frequency processing chip 1, CPLD, MCU, motor-driven lens driven unit 4 connects in turn, preferably, described CPLD is connected by I2C interface with MCU, the standard digital vision signal of described video frequency processing chip output is carried out to brightness extraction to described CPLD and autofocus evaluation function calculates, output autofocus evaluation function value, described MCU carries out search by hill climbing algorithm according to described focus function evaluation of estimate and calculates output motor control signal, described motor-driven lens driven unit is controlled focus motor according to described motor control signal and is completed automatic focus.
The present embodiment adopts CPLD and MCU cooperation cheaply, carries out task distribution, realizes the auto-focus function of totally digitilized high-timeliness, is that a kind of high-definition camera is cheaply realized self-focusing design.Concrete, video frequency processing chip described in high-definition camera 1 is reserved with 8bit digital video signal output interface, configures the digital video signal of this interface outputting standard, such as BT.656 signal, adopts this signal as focusing algorithm video source signal.The 8bit digital video signal output interface outputting standard digital video signal of video frequency processing chip 1, described standard digital vision signal is carried out to brightness extraction to CPLD and autofocus evaluation function calculates, by I2C interface, export autofocus evaluation function value to MCU, MCU carries out data statistics according to autofocus evaluation function value, use search by hill climbing algorithm to calculate output motor control signal, described motor-driven lens driven unit 4 is controlled focus motor according to described motor control signal and is completed automatic focus.Preferably, described motor control signal is pwm signal, and described motor-driven lens driven unit 4 comprises H bridge chip, focus motor.Concrete, after MCU calculates by hill-climbing algorithm, export 2 road pwm signals to H bridge chip (the motor drive ic BD6220 of ROHM company), by changing PWM duty, recently change drive current size and direction, thereby drive focus motor running to realize auto-focus function.
As a kind of specific implementation, as shown in Figure 2, described CPLD comprises:
Brightness extraction unit 21, for identifying effective video data according to the guidance code of standard digital vision signal, and goes out luminance component from described effective video extracting data;
Focus on evaluation unit 22, for calculating autofocus evaluation function value according to described luminance component and autofocus evaluation function.
BT.656 standardized digital signal take below as example, the specific works mode of CPLD is described.
BT.656 digital signal (claims again CCIR656, form is YCbCr4:2:2) in comprised video synchronization signal, brightness (Y) signal and colourity (C) signal, what wherein effectively reflecting video focused on definition values is the high fdrequency component in luminance signal, therefore brightness extraction unit 21 needs first BT.656 digital video to be carried out to brightness signal extraction, filters out useless colourity and synchronizing signal.According to the difference of Output system, the number format of BT.656 also can be slightly different, for TSC-system formula, is 525/60, and a two field picture is 525 row, and field frequency is 60Hz; For pal mode, be 625/50, a two field picture is 625 row, and field frequency is 50Hz, and they are all interlacing output.For the BT.656 image of pal mode, the digital picture valid pixel size of output is 720 * 576.
As shown in Figure 3, for the row data of BT.656, it mainly comprises synchronizing signal and brightness, carrier chrominance signal to the BT.656 image line output timing of pal mode.Wherein, synchronizing signal is effective video beginning label (SAV) and effective video end mark (EAV), utilize these guidance codes, can complete that row is synchronous, the judgement of the state such as field synchronization and brightness and colourity valid data, synchronizing signal synchronously provides effective foundation for CPLD is soft simultaneously.The output of row valid data is sequentially followed successively by: Cb, Y, Cr, Y, Cb, Y, Cr, Y ..., two adjacent gray component Y share a color difference signal Cb or Cr, have 720 Y-signals, can generate 720 row pixels.Because image is interlacing output, i.e. odd an of two field picture and occasionally field, thus in the digital picture of 625 row, except the blank lines of decorrelation, the strange field data of remaining 288 row,, the even field data of 288 row, forms 576 row effective video data altogether.Therefore by the guidance code in BT.656 digital signal, can identify effective video data.
Brightness extraction unit 21 extracts luminance component Y(8bit) after, focus on evaluation unit 22 and calculate autofocus evaluation function value according to described luminance component and autofocus evaluation function.In the present embodiment, adopt a kind of improved gray scale difference point-score as autofocus evaluation function, this is the autofocus evaluation function after a kind of optimization, described autofocus evaluation function be all pixels of a two field picture and its surrounding pixel luminance difference square cumulative, as the expression way of a kind of autofocus evaluation function F, as follows:
F = Σ x Σ y ( | f ( x , y ) - f ( x , y - 1 ) | 2 + | f ( x , y ) - f ( x - 1 , y ) | 2 + | f ( x , y ) - f ( x + 1 , y - 1 ) | 2 + | f ( x , y ) - f ( x - 1 , y - 1 ) | 2 )
Above-mentioned f(x, y) for row row-coordinate is respectively x, the luma component values of the pixel of y (being assumed to be A point), f(x, y-1) be the luma component values of pixel directly over A point, f(x-1, y) be the brightness value of A point front-left pixel, f(x+1, y-1) be the luma component values of A point upper right side pixel, f(x-1, y-1) be the luma component values of A point upper left pixel point.
When selection, as a kind of example, enumerate, concrete, described CPLD can adopt the EPM240T100C5 chip of ALTERA company, and this chip is the MAX II series that ALTERA releases, and has 240 logical blocks, 192 macrocells of equivalence; With previous generation MAX series contrast, it is original 1/10 that power consumption eases down to, and supports to be up to the internal clocking frequency of 300MHz, and between wire structures pin, time delay is also low to moderate 3.6ns, and interior while, portion provided 8k bit Flash, and resource can meet design requirement.CPLD signal adopts SAV, EAV that BT.656 provides as soft synchronous sequence control signal in processing, can from BT.656 video data stream, judge accurately and extract brightness Y-signal, realize bright, chrominance information is separated and filtering synchronously and carrier chrominance signal.
As a kind of specific implementation, as shown in Figure 4, described MCU comprises:
Search by hill climbing unit 41, constantly the position of vernier focusing camera lens, calculates focal position according to three of state-of-the-art record focus function evaluations of estimate, exports corresponding motor control signal.
Preferably, described MCU also comprises:
Focus on filter element 40, for adding up the numerical difference between of adjacent two focus function evaluations of estimate, filter out the focus function evaluation of estimate of described numerical difference between outside predetermined threshold value scope.
The single-threaded complex logic calculation process of MCU is stronger, the present embodiment utilizes this feature, MCU carries out statistical computation to focus function evaluation of estimate, concrete, MCU receives after autofocus evaluation function value, focus on filter element 40 and first record functional value result, calculate the numerical difference between between adjacent two focus function evaluations of estimate, and compare with predetermined threshold value scope, filter the not focus function evaluation of estimate within the scope of described predetermined threshold value of described numerical difference between, can get rid of like this and useless by video noise, cause that ultralow squared differences or invalid video disturb the superelevation variance yields causing, experimental results show that and can effectively promote automatic focus antijamming capability and focusing speed.
Autofocus evaluation function value has the feature of unimodality and unbiasedness, when focusing realizes, image experienced one by fuzzy to clear to fuzzy again to process clearly, and image is the most clearly time, autofocus evaluation function value is maximum.The relation that curve reflection autofocus evaluation function value as shown in Figure 5 and focus motor are rotated step number, wherein the value of transverse axis sensing positive direction is motor forward, pointing to reciprocal value is motor reversion, motor is adjusted lens location in rotation process, when motor is therein during a certain position, image is the most clear.
Lens location is constantly adjusted by output control signal in search by hill climbing unit 41, in this process, CPLD constantly exports autofocus evaluation function value, the present embodiment utilizes search by hill climbing algorithm, search by hill climbing algorithm schematic diagram as shown in Figure 6, suppose that amasthenic lens is current in mi position, each stepping M, therefore high fdrequency component (being the autofocus evaluation function value that under diverse location, CPLD exports) F(mi) and size F(mi+M) determine the moving direction of camera lens, 3 values of cycle index in MCU built-in RAM, be recorded as respectively high fdrequency component value F(mi-M), F(mi), F(mi+M), recording mode is up time displacement record successively, record three up-to-date focus function evaluations of estimate at every turn like this.By calculating, find when camera lens is positioned at position mx, there is F (mx-M) <F (mx) >F (mx+M) to set up, because autofocus evaluation function value has unimodality, therefore focal position mp, between (mx-M) to (mx+M), can be obtained by following formula:
Figure BDA0000412196250000061
d1=F (mx)-F (mx-M) wherein, D2=F (mx)-F (mx+M).Obtain after focal position, MCU exports 2 road pwm signals to H bridge chip (the motor drive ic BD6220 of ROHM company), by changing PWM duty, recently changes drive current size and direction, thereby drives focus motor running to realize auto-focus function.
The search by hill climbing algorithm amount of calculation that the present embodiment provides is little, and the calculation process time is short, can be by the weak MCU calculation process of operational capability.As a kind of selection mode, described MCU can adopt the STM32F101R6 chip of ST company, and this chip adopts the Cortex-M3 of ARM32 position tMcPU, has the system clock frequency of 36MHz, 128k Flash memory and 16k SRAM, and 3 16 bit timing devices nearly, each timer has nearly 4 passages for input capture/output comparison/PWM or step-by-step counting, 7 DMA channel controllers; Support 2 I2C, 2 SPI and 3 USART etc.Interface and processor performance meet design requirement completely.
The Material Cost inventory of the automatic focus scheme that the present embodiment provides is as following table:
Sequence number Name of material Model specification Consumption Price (RMB)
1 CPLD EPM240T100C5 100TQFP 1 5.5 first
2 MCU STM32F101R6 LQFP64 1 12.5 yuan
3 Crystal oscillator 8MHz 20ppm 1 0.80 yuan
4 H bridge DB6220 2 3.2 first
4 Capacitance resistance ware Multiple Type joint account 65 1.6 first
Amount to 23.24 yuan
From above raw material statistics cost, present design Material Cost is low to moderate 23.24 yuan, approximately only has 50% left and right of a slice fpga chip cost, and with the existing automatic focus scheme contrast of existing market, cost advantage is obvious.
To sum up, the invention provides a kind of CPLD of employing is combined with MCU and realizes the low-cost technologies solution of auto-focus function.According to CPLD, there is very high parallel data operational capability and MCU has good single-threaded complex calculation disposal ability, Processing tasks to CPLD and MCU distributes, wherein CPLD has realized the high speed BT.656 parallel data processing of similar FPGA, reduce automatic focus time delays, MCU carries out totally digitilized Video processing.Show after tested, camera automatic focusing provided by the invention is quick on the draw, and automatic focus accuracy height is respond well, applicable to outdoor, indoor and night low-illumination environment, wide accommodation.
The foregoing is only preferred embodiment of the present invention, not in order to limit the present invention, all any modifications of doing within the spirit and principles in the present invention, be equal to and replace and improvement etc., within all should being included in protection scope of the present invention.

Claims (8)

1. the automatic focus high-definition camera based on CPLD and MCU, the video frequency processing chip and the motor-driven lens driven unit that comprise exportable standard digital vision signal, it is characterized in that, described video camera also comprises CPLD and MCU, the standard digital vision signal of described video frequency processing chip output is carried out to brightness extraction to described CPLD and autofocus evaluation function calculates, output autofocus evaluation function value, described MCU carries out search by hill climbing algorithm according to described focus function evaluation of estimate and calculates output motor control signal, described motor-driven lens driven unit is controlled focus motor according to described motor control signal and is completed automatic focus.
2. the automatic focus high-definition camera based on CPLD and MCU as claimed in claim 1, is characterized in that, described CPLD comprises:
Brightness extraction unit, for identifying effective video data according to the guidance code of standard digital vision signal, and goes out luminance component from described effective video extracting data;
Focus on evaluation unit, for calculating autofocus evaluation function value according to described luminance component and autofocus evaluation function.
3. the automatic focus high-definition camera based on CPLD and MCU as claimed in claim 2, is characterized in that, described autofocus evaluation function be all pixels of a two field picture and its surrounding pixel luminance difference square cumulative.
4. the automatic focus high-definition camera based on CPLD and MCU as claimed in claim 3, is characterized in that, described MCU comprises:
Search by hill climbing unit, constantly the position of vernier focusing camera lens, calculates focal position according to three of state-of-the-art record focus function evaluations of estimate, exports corresponding motor control signal.
5. as right, want the automatic focus high-definition camera based on CPLD and MCU as described in 4, it is characterized in that, described MCU also comprises:
Focus on filter element, for adding up the numerical difference between of adjacent two focus function evaluations of estimate, filter out the focus function evaluation of estimate of described numerical difference between outside predetermined threshold value scope.
6. the automatic focus high-definition camera based on CPLD and MCU as described in claim 1-5 any one, is characterized in that, described CPLD is connected by I2C interface with MCU.
7. the automatic focus high-definition camera based on CPLD and MCU as claimed in claim 6, is characterized in that, described motor control signal is pulse width modulating signal.
8. the automatic focus high-definition camera based on CPLD and MCU as claimed in claim 7, is characterized in that, described standard digital vision signal is BT.656YCbCr4:2:2 digital video signal.
CN201310558097.3A 2013-11-12 2013-11-12 A kind of automatically focus on high-definition camera based on CPLD and MCU Active CN103561203B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201310558097.3A CN103561203B (en) 2013-11-12 2013-11-12 A kind of automatically focus on high-definition camera based on CPLD and MCU

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201310558097.3A CN103561203B (en) 2013-11-12 2013-11-12 A kind of automatically focus on high-definition camera based on CPLD and MCU

Publications (2)

Publication Number Publication Date
CN103561203A true CN103561203A (en) 2014-02-05
CN103561203B CN103561203B (en) 2016-06-22

Family

ID=50015346

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201310558097.3A Active CN103561203B (en) 2013-11-12 2013-11-12 A kind of automatically focus on high-definition camera based on CPLD and MCU

Country Status (1)

Country Link
CN (1) CN103561203B (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110809113A (en) * 2019-01-25 2020-02-18 云南师范大学 Infrared imaging automatic focusing system based on FPGA
CN114112066A (en) * 2021-11-26 2022-03-01 山东神戎电子股份有限公司 Infrared thermal imager rapid automatic focusing method based on target identification and space learning

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN201788026U (en) * 2010-07-27 2011-04-06 凯迈广微（洛阳）光电设备有限公司 Front-end dynamic forest fire recognizing and alarming system and thermal infrared imager thereof
JP2011071623A (en) * 2009-09-24 2011-04-07 Canon Inc Imaging apparatus
CN102053339A (en) * 2010-11-23 2011-05-11 天津市亚安科技电子有限公司 Automatic focusing method
CN103217855A (en) * 2013-04-02 2013-07-24 金三立视频科技（深圳）有限公司 Automatic focusing method of camera

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011071623A (en) * 2009-09-24 2011-04-07 Canon Inc Imaging apparatus
CN201788026U (en) * 2010-07-27 2011-04-06 凯迈广微（洛阳）光电设备有限公司 Front-end dynamic forest fire recognizing and alarming system and thermal infrared imager thereof
CN102053339A (en) * 2010-11-23 2011-05-11 天津市亚安科技电子有限公司 Automatic focusing method
CN103217855A (en) * 2013-04-02 2013-07-24 金三立视频科技（深圳）有限公司 Automatic focusing method of camera

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110809113A (en) * 2019-01-25 2020-02-18 云南师范大学 Infrared imaging automatic focusing system based on FPGA
CN114112066A (en) * 2021-11-26 2022-03-01 山东神戎电子股份有限公司 Infrared thermal imager rapid automatic focusing method based on target identification and space learning
CN114112066B (en) * 2021-11-26 2024-04-26 山东神戎电子股份有限公司 Rapid automatic focusing method of thermal infrared imager based on target identification and space learning

Also Published As

Publication number Publication date
CN103561203B (en) 2016-06-22

Similar Documents

Publication Publication Date Title
CN101739827B (en) Vehicle detecting and tracking method and device
CN102521990B (en) Control method of intelligent traffic light based on image processing
CN202887451U (en) Infrared light and visible light filling blended electronic police system
CN102914667B (en) Large-scale particle image velocimeter based on near-infrared smart camera
CN109151390B (en) Ultralow-illumination night vision method and system and high-definition camera device
CN104376732A (en) Intelligent traffic light based on signal control processing technology and signal control method
CN104134352A (en) Video vehicle characteristic detection system and detection method based on combination of long exposure and short exposure
CN101719217A (en) Elastic relaxation algorithm-based vehicle type identification system and elastic relaxation algorithm-based vehicle type identification method
CN103136938A (en) Pedestrian crossing passage traffic light intelligent control system
CN102946515A (en) Full-automatic focusing device and method for infrared imaging equipment
CN107248296B (en) Video traffic flow statistical method based on unmanned aerial vehicle and time sequence characteristics
CN106954046B (en) Video acquisition device and method
CN110620885B (en) Infrared low-light-level image fusion system and method and electronic equipment
CN105430362A (en) Imaging method, imaging device and electronic device
CN103646546A (en) An intelligent traffic system with a large-scale vehicle passing-forbidding function
CN105578066A (en) Imaging method, imaging device and electronic device
CN102306274A (en) Device for identifying parking space state and method
CN202352075U (en) Five-in-one electronic police system
CN113074714A (en) Multi-state potential sensing sensor based on multi-data fusion and processing method thereof
CN103905691A (en) Method for obtaining sharp image through penetration through rain, snow and fog, and photographing system
CN103561203A (en) Automatic focusing high-definition camera based on CPLD and MCU
CN208128386U (en) A kind of high-resolution large area array imaging circuit system
CN107808529B (en) Traffic light control method and system based on local intersection video monitoring
CN102184711A (en) Backlight driving method and backlight driving device
CN105430297B (en) The automatic control system that more video formats are changed to IIDC protocol videos form

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant