CN103729619B - The automatic identifying method of car plate frame in preventing road monitoring system - Google Patents

Abstract

Car license recognition applied technical field during the automatic identifying method of car plate frame belongs to urban road monitor system in preventing road monitoring system, in this preventing road monitoring system, the automatic identifying method of car plate frame is by defining the scanning recognition district of an isosceles triangle, and make this cog region move along given identification path respectively, realize the screening to the topography including the doubtful frame of car plate in entire image, and by acquired multiple straight line set being identified and judgement process, finally realize filtering out the profile of car plate frame from view picture photo.This automatic identifying method also has that operand is little, speed fast, the most reliable and be easy to advantages such as popularizing.

Description

The automatic identifying method of car plate frame in preventing road monitoring system

Technical field

The invention belongs to Car license recognition applied technical field in urban road monitor system, be specifically related to a kind of road The automatic identifying method of car plate frame in the monitoring system of road.

Background technology

In the last few years, urban highway traffic quickly grows, for more preferable management road traffic, quickly Accurately detecting vehicles peccancy, Vehicular intelligent supervisory systems is set up in each city successively.In the case of unmanned participation, Monitoring road can be carried out by existing urban road monitor system by vehicle speed measuring device and shooting camera system Automatic camera, obtains the photo including target vehicle and car plate thereof.

But automatically identify that car plate violating the regulations is then a more complicated image recognition processing process, existing car Board recognition methods many employings edge extracting image processing algorithm, is identified view picture photograph image processing, this Kind of method not only operand is huge, processes the time long, is also easily subject in photo other beyond car plate simultaneously The interference of image information, causes the error of recognition result even to directly result in mistake.

Therefore, research and develop a kind of taking the lead in from the view picture photograph image including car plate and identify and filter out car plate wheel Wide boundary line, is accurately positioned car plate present position in photo, in order to get rid of the image district of non-car plate in photo Territory, the most again by subsequent treatment, completes the quickly identification to the number-plate number image within car plate border Method, becomes problem demanding prompt solution.

Summary of the invention

In order to solve existing licence plate recognition method many employings edge extracting image processing algorithm, to view picture photo Image is identified processing, and not only operand is huge, processes the time long, is also easily subject to car in photo simultaneously The interference of other image information beyond board, causes the error of recognition result even to directly result in mistake, therefore Need to research and develop a kind of can taking the lead in from the view picture photograph image including car plate identify and filter out license plate outline limit The technical problem of the licence plate recognition method in boundary line, the present invention provides car plate frame in a kind of preventing road monitoring system Automatic identifying method.

It is as follows that the present invention solves the technical scheme that technical problem taked:

In a kind of preventing road monitoring system, the automatic identifying method of car plate frame comprises the steps:

The first step, the original image that the resolution taken by preventing road monitoring system is 768 × 576 pixels is entered Row edge extracting, it is thus achieved that bianry image E, in bianry image E gray value be 1 point represent marginal point, ash Angle value be 0 point represent non-edge point, with the upper left corner of bianry image E as initial point, set up x-axis level to Right, y-axis pixel planes rectangular coordinate system straight down；

Second step, acquisition comprise the straight line set U of doubtful horizontal sides wire section₁, it specifically includes following sub-step Rapid:

Step 2.1: two scanning patterns on the cog region of definition isosceles triangle and horizontal direction:

Defining the cog region of horizontal isosceles triangle, the drift angle of this isosceles triangle is 30 degree and towards x-axis just Direction, the pixel (729,0) that the straight line at the place, base of isosceles triangle is perpendicular in x-axis；Isosceles three The center line of dihedral is parallel with x-axis；58 oblique line sections, described 58 oblique lines are also comprised in this isosceles triangle Duan Jun is with the drift angle of isosceles triangle as starting point, and base is terminal, and is positioned at coordinate system range described in step one Within；In this isosceles triangle in 61 line segments altogether including two stringcourses and a center line, arbitrarily The adjacent angle between two is 0.5 degree；

Choose with pixel a₁(40,40) are starting point with pixel a₇₂₈(729,40) are the line of terminal Section a, and choose with pixel (40,537) and be starting point and be the line of terminal with pixel (729,537) B is as the scanning pattern in two horizontal directions for section；The length of line segment a and line segment b is 690 pixels Point, and both is parallel with x-axis；

Step 2.2: the cog region drift angle of isosceles triangle is along the scanning recognition process of horizontal line section a, and it is concrete Including following sub-step:

Step 2.2.1: upper a certain to fixation by the drift angle of the cog region of horizontal isosceles triangle and line segment a Vegetarian refreshments overlaps, and corresponding with oblique line section by the abscissa value renewal array of current given pixel, oblique line section Linear equation；Its specific practice is:

Make the drift angle of the cog region of horizontal isosceles triangle described in step 2.1 and a certain given pixel on line segment a Point overlaps, and the sequence number of the drift angle position of the cog region of the most horizontal isosceles triangle is defined as a_n, its Middle n=x-39, in formula, x is the abscissa value that current corner place gives pixel；

When the sequence number of the drift angle position of the cog region of horizontal isosceles triangle is a_nTime, define this isosceles three Serial number Fa of each bar oblique line section in dihedral_n-k(k sequentially takes 01,02,03 ... 61)；By oblique line section Fa_n-01 On the coordinate figure of each pixel be all stored in line segment array data [a_n-01In], by same method, by it Its each oblique line section a_n-kOn the coordinate figure of each pixel be all stored in and this line segment sequence number Fa_n-kCorresponding Line segment array data [a_n-k] in (k sequentially takes 01,02,03 ... 61)；

Step 2.2.2: when completing the cog region drift angle current given coordinate points on horizontal line section a, to identification Whether each oblique line section in district has judgement identification and the screening of doubtful car plate frame line segment；It specifically wraps Include following sub-step:

Step 2.2.2.1: the drift angle of the cog region of horizontal isosceles triangle is in starting point a of line segment a₁(40,40) Time, select oblique line section Fa in current cog region_1-01；

Step 2.2.2.2: judge acquired by step 2.2.1 and oblique line section Fa_n-kCorresponding line segment array data[a_n-kIn], on a bit of line segment being made up of every 40 continuous image vegetarian refreshments, if at least 36 steps Marginal point described in rapid one, if having, then containing doubtful car plate frame line segment in this oblique line section, enters step 2.2.2.3；If no, then entering step 2.2.2.4；

Step 2.2.2.3: linea oblique anterior section Fa will be worked as_n-kLinear equation La corresponding under pixel coordinate system_n-kIt is stored in Array U₁, complete when linea oblique anterior section Fa_n-kThe identification screening of upper doubtful frame, and enter step 2.2.2.4；

Step 2.2.2.4: judge current line segment array data [a_n-k] (k sequentially takes 01,02,03 ... 61) In, whether k is 61, if k ≠ 61, then enters step 2.2.2.5；If k=61, then enter step 2.2.3；

Step 2.2.2.5: make k=k+1(k sequentially take 01,02,03 ... 61), update step 2.2.2.2 institute State oblique line section Fa_n-kAnd line segment array data [a corresponding thereto_n-k] sequence number, re-execute step 2.2.2.2 To step 2.2.2.4；

Step 2.2.3: make the drift angle of cog region of horizontal isosceles triangle from starting point a of line segment a₁(40,40) A pixel unit is sequentially moved horizontally, after each drift angle moves a new position, all to x-axis positive direction Update the drift angle a of the cog region of horizontal isosceles triangle described in step 2.2.2.1_n, and repeated execution of steps 2.2.2, Until the drift angle of the cog region of horizontal isosceles triangle moves the terminal a to line segment a₇₂₉Time (729,40), By a_nIt is updated to a₆₉₀, subsequently into step 2.3；

Step 2.3: by the cog region drift angle of isosceles triangle by the terminal a of the line segment a described in step 2.1₇₂₉ (729,40) change the starting point (40,537) to line segment b, and according to complete with the method as step 2.2 Becoming the cog region drift angle scanning recognition process along horizontal line section b of isosceles triangle, it specifically includes following son Step:

Step 2.3.1: upper a certain to fixation by the drift angle of the cog region of horizontal isosceles triangle and line segment b Vegetarian refreshments overlaps, and corresponding with oblique line section by the abscissa value renewal array of current given pixel, oblique line section Linear equation；Its specific practice is:

Make the drift angle of the cog region of horizontal isosceles triangle described in step 2.1 and a certain given pixel on line segment b Point overlaps, and the sequence number of the drift angle position of the cog region of the most horizontal isosceles triangle is defined as b_n, its Middle n=x-39, in formula, x is the abscissa value that current corner place gives pixel；

When the sequence number of the drift angle position of the cog region of horizontal isosceles triangle is b_nTime, define this isosceles three Serial number Fb of each bar oblique line section in dihedral_n-k(k sequentially takes 01,02,03 ... 61)；By oblique line section Fb_n-01On the coordinate figure of each pixel be all stored in line segment array data [b_n-01In], by same method, By other each oblique line section b_n-kOn the coordinate figure of each pixel be all stored in and this line segment sequence number Fb_n-k Corresponding line segment array data [b_n-k] in (k sequentially takes 01,02,03 ... 61)；

Step 2.3.2: when completing the cog region drift angle current given coordinate points on horizontal line section b, to identification Whether each oblique line section in district has judgement identification and the screening of doubtful car plate frame line segment；It specifically wraps Include following sub-step:

Step 2.3.2.1: the drift angle of the cog region of horizontal isosceles triangle is in starting point b of line segment b₁(40,40) Time, select oblique line section Fb in current cog region_1-01；

Step 2.3.2.2: judge acquired by step 2.3.1 and oblique line section Fb_n-kCorresponding line segment array data[b_n-kIn], on a bit of line segment being made up of every 40 continuous image vegetarian refreshments, if at least 36 steps Marginal point described in rapid one, if having, then containing doubtful car plate frame line segment in this oblique line section, enters step 2.3.2.3；If no, then entering step 2.3.2.4；

Step 2.3.2.3: linea oblique anterior section Fb will be worked as_n-kLinear equation Lb corresponding under pixel coordinate system_n-kIt is stored in Array U₁, complete when linea oblique anterior section Fb_n-kThe identification screening of upper doubtful frame, and enter step 2.3.2.4；

Step 2.3.2.4: judge present segment array data [b_n-k] in (k sequentially takes 01,02,03 ... 61), Whether k is 61, if k ≠ 61, then enters step 2.3.2.5；If k=61, then enter step 2.3.3；

Step 2.3.2.5: make k=k+1(k sequentially take 01,02,03 ... 61), update step 2.3.2.2 institute State oblique line section Fb_n-kAnd line segment array data [b corresponding thereto_n-k] sequence number, re-execute step 2.3.2.2 To step 2.3.2.4；

Step 2.3.3: make the drift angle of cog region of horizontal isosceles triangle from starting point b of line segment b₁(40,537) A pixel unit is sequentially moved horizontally, after each drift angle moves a new position, all to x-axis positive direction Update the drift angle b of the cog region of horizontal isosceles triangle described in step 2.3.2.1_n, and repeated execution of steps 2.3.2, Until the drift angle of the cog region of horizontal isosceles triangle moves the terminal b to line segment b₇₂₉Time (729,40), By b_nIt is updated to b₆₉₀, complete the cog region drift angle scanning recognition process along horizontal line section b of isosceles triangle, Subsequently into step 3；

Step 3, acquisition comprise the straight line set U of doubtful vertical edge wire section₂, it specifically includes following sub-step Rapid: step 3.1: two scanning patterns on the cog region of definition isosceles triangle and vertical direction:

Defining the cog region of vertical isosceles triangle, the drift angle of this isosceles triangle is 30 degree and towards y-axis just Direction, the pixel (0,537) that the straight line at the place, base of isosceles triangle is perpendicular in y-axis；Isosceles three The center line of dihedral is parallel with y-axis；58 oblique line sections, described 58 oblique lines are also comprised in this isosceles triangle Duan Jun is with the drift angle of isosceles triangle as starting point, and base is terminal, and is positioned at coordinate system range described in step one Within；In this isosceles triangle in 61 line segments altogether including two stringcourses and a center line, arbitrarily The adjacent angle between two is 0.5 degree；

Choosing with pixel (40,40) is starting point with the line segment c that pixel (40,537) is terminal, And choose with pixel (729,40) and be starting point and make with line segment d that pixel (729,537) is terminal It it is the scanning pattern on two vertical directions；The length of line segment c and line segment d is 498 pixels, and Both is parallel with y-axis；

Step 3.2: the cog region drift angle of isosceles triangle is along the scanning recognition process of vertical line segment c, and it is concrete Including following sub-step:

Step 3.2.1: upper a certain to fixation by the drift angle of the cog region of vertical isosceles triangle and line segment c Vegetarian refreshments overlaps, and corresponding with oblique line section by the abscissa value renewal array of current given pixel, oblique line section Linear equation；Its specific practice is:

Make the drift angle of the cog region of vertical isosceles triangle described in step 3.1 and a certain given pixel on line segment c Point overlaps, and the sequence number of the now drift angle position of the cog region of vertical isosceles triangle is defined as c_n, its Middle n=y-39, in formula, y is the ordinate value that current corner place gives pixel；

When the sequence number of the drift angle position of the cog region of vertical isosceles triangle is c_nTime, define this isosceles three Serial number Fc of each bar oblique line section in dihedral_n-k(k sequentially takes 01,02,03 ... 61)；By oblique line section Fc_n-01 On the coordinate figure of each pixel be all stored in line segment array data [c_n-01In], by same method, by it Its each oblique line section c_n-kOn the coordinate figure of each pixel be all stored in and this line segment sequence number Fc_n-kCorresponding Line segment array data [c_n-k] in (k sequentially takes 01,02,03 ... 61)；

Step 3.2.2: when completing the cog region drift angle current given coordinate points on vertical line segment c, to identification Whether each oblique line section in district has judgement identification and the screening of doubtful car plate frame line segment；It specifically wraps Include following sub-step:

Step 3.2.2.1: vertically the drift angle of the cog region of isosceles triangle is in starting point c of line segment c₁(40,40) Time, select oblique line section Fc in current cog region_1-01；

Step 3.2.2.2: judge acquired by step 3.2.1 and oblique line section Fc_n-kCorresponding line segment array data[c_n-kIn], on a bit of line segment being made up of every 40 continuous image vegetarian refreshments, if at least 36 steps Marginal point described in rapid one, if having, then containing doubtful car plate frame line segment in this oblique line section, enters step 3.2.2.3；If no, then entering step 3.2.2.4；

Step 3.2.2.3: linea oblique anterior section Fc will be worked as_n-kLinear equation Lc corresponding under pixel coordinate system_n-kIt is stored in Array U₂, complete when linea oblique anterior section Fc_n-kThe identification screening of upper doubtful frame, and enter step 3.2.2.4；

Step 3.2.2.4: judge current line segment array data [c_n-k] (k sequentially takes 01,02,03 ... 61) In, whether k is 61, if k ≠ 61, then enters step 3.2.2.5；If k=61, then enter step 3.2.3；

Step 3.2.2.5: make k=k+1(k sequentially take 01,02,03 ... 61), update step 3.2.2.2 institute State oblique line section Fc_n-kAnd line segment array data [c corresponding thereto_n-k] sequence number, re-execute step 3.2.2.2 To step 3.2.2.4；

Step 3.2.3: make the drift angle of cog region of vertical isosceles triangle from starting point c of line segment c₁(40,40) A pixel unit is the most vertically moved, after each drift angle moves a new position, all to y-axis positive direction Update the drift angle c of the vertically cog region of isosceles triangle described in step 3.2.2.1_n, and repeated execution of steps 3.2.2, Until vertically the drift angle of the cog region of isosceles triangle moves the terminal c to line segment c₄₉₈Time (40,537), By c_nIt is updated to c₄₉₈, subsequently into step 3.3；

Step 3.3: by the cog region drift angle of isosceles triangle by the terminal c of the line segment c described in step 3.1₄₉₈ (40,537) change the starting point (729,40) to line segment d, and according to complete with the method as step 3.2 Becoming the cog region drift angle scanning recognition process along vertical line segment d of isosceles triangle, it specifically includes following son Step:

Step 3.3.1: upper a certain to fixation by the drift angle of the cog region of vertical isosceles triangle and line segment d Vegetarian refreshments overlaps, and corresponding with oblique line section by the ordinate value renewal array of current given pixel, oblique line section Linear equation；Its specific practice is:

Make the drift angle of the cog region of vertical isosceles triangle described in step 3.1 and a certain given pixel on line segment d Point overlaps, and the sequence number of the now drift angle position of the cog region of vertical isosceles triangle is defined as d_n, its Middle n=y-39, in formula, y is the ordinate value that current corner place gives pixel；

When the sequence number of the drift angle position of the cog region of vertical isosceles triangle is d_nTime, define this isosceles three Serial number Fd of each bar oblique line section in dihedral_n-k(k sequentially takes 01,02,03 ... 61)；By oblique line section Fd_n-01On the coordinate figure of each pixel be all stored in line segment array data [d_n-01In], by same method, By other each oblique line section d_n-kOn the coordinate figure of each pixel be all stored in and this line segment sequence number Fd_n-k Corresponding line segment array data [d_n-k] in (k sequentially takes 01,02,03 ... 61)；

Step 3.3.2: when completing the cog region drift angle current given coordinate points on vertical line segment d, to identification Whether each oblique line section in district has judgement identification and the screening of doubtful car plate frame line segment；It specifically wraps Include following sub-step:

Step 3.3.2.1: vertically the drift angle of the cog region of isosceles triangle is in starting point d of line segment d₁(729,40) Time, select oblique line section Fd in current cog region_1-01；

Step 3.3.2.2: judge acquired by step 3.3.1 and oblique line section Fd_n-kCorresponding line segment array data[d_n-kIn], on a bit of line segment being made up of every 40 continuous image vegetarian refreshments, if at least 36 steps Marginal point described in rapid one, if having, then containing doubtful car plate frame line segment in this oblique line section, enters step 3.3.2.3；If no, then entering step 3.3.2.4；

Step 3.3.2.3: linea oblique anterior section Fd will be worked as_n-kLinear equation Ld corresponding under pixel coordinate system_n-kIt is stored in Array U₂, complete when linea oblique anterior section Fd_n-kThe identification screening of upper doubtful frame, and enter step 3.3.2.4；

Step 3.3.2.4: judge present segment array data [d_n-k] in (k sequentially takes 01,02,03 ... 61), Whether k is 61, if k ≠ 61, then enters step 3.3.2.5；If k=61, then enter step 3.3.3；

Step 3.3.2.5: make k=k+1(k sequentially take 01,02,03 ... 61), update step 3.3.2.2 institute State oblique line section Fd_n-kAnd line segment array data [d corresponding thereto_n-k] sequence number, re-execute step 3.3.2.2 To step 3.3.2.4；

Step 3.3.3: make the drift angle of cog region of vertical isosceles triangle from starting point d of line segment d₁(729,40) A pixel unit is the most vertically moved, after each drift angle moves a new position, all to y-axis positive direction Update the drift angle d of the vertically cog region of isosceles triangle described in step 3.3.2.1_n, and repeated execution of steps 3.3.2, Until vertically the drift angle of the cog region of isosceles triangle moves the terminal d to line segment d₄₉₈Time (729,537), By d_nIt is updated to d₄₉₈, complete the cog region drift angle scanning recognition process along vertical line segment d of isosceles triangle, Subsequently into step 4；

Step 4: straight line set U described in read step two respectively₁With straight line set U described in step 3₂, and sentence Disconnected logical formula U₁&U₂Result, if its result is true, then enter step 5, if its result is false, the most directly Connect the identification process terminating this method；

Step 5: according to the slope result of product of two intersecting straight lines, it is judged that whether meet both it and hang down each other Straight condition, from U₁Middle screening retains energy and U₂In the most vertical straight line of two straight lines, by qualified Straight line is stored in set U₃, subsequently into step 6；

Step 6: according to the slope result of product of two intersecting straight lines, it is judged that whether meet both it and hang down each other Straight condition, from U₂Middle screening retains energy and U₃In the most vertical straight line of two straight lines, by qualified Straight line is stored in set U₄, subsequently into step 7；

Step 7: according to the slope result of product of two intersecting straight lines, it is judged that whether meet both it and hang down each other Straight condition, it is judged that set U₄In whether have two straight lines can simultaneously and U₃In two straight lines vertical, then Enter step 8；

Step 8: obtained the linear equation of rectangle four edges line by step 7 respectively, the four edges line of this rectangle It is the car plate doubtful boundary line in photo.

The slope result of product according to two intersecting straight lines described in step 5 or step 6 or step 7, sentences Disconnected whether meet condition perpendicular to one another both it criterion be:

Any two linear equations are denoted as respectively: straight line 1:y₁=k₁x+b₁；Straight line 2:y₂=k₂x+b₂；Then Judgement formula: E=k can be obtained₁×k₂；

If the result value of E is in interval [-1.05 ,-0.95], then it is assumed that two straight lines are perpendicular to one another.

The invention has the beneficial effects as follows: in this preventing road monitoring system, the automatic identifying method of car plate frame is by fixed The scanning recognition district of one isosceles triangle of justice, and make this cog region move along given identification path respectively, Realize the screening to the topography including the doubtful frame of car plate in entire image, and by acquired Multiple straight line set are identified and judgement processes, and finally realize filtering out car plate frame from view picture photo Profile.This automatic identifying method also has that operand is little, speed fast, the most reliable and be easy to promote general And etc. advantage.

Accompanying drawing explanation

Fig. 1 is the block schematic illustration of the cog region of isosceles triangle of the present invention；

Fig. 2 is cog region and the schematic diagram of scanning pattern thereof of isosceles triangle of the present invention；

Fig. 3 is the general flow chart of the automatic identifying method of car plate frame in preventing road monitoring system of the present invention；

Fig. 4 is the sub-process figure of step 2 of the present invention；

Fig. 5 is the sub-process figure of step 3 of the present invention；

Fig. 6 is the sub-process figure of step 2.2 of the present invention；

Fig. 7 is the sub-process figure of step 2.2.2 of the present invention；

Fig. 8 is the sub-process figure of step 2.3 of the present invention；

Fig. 9 is the sub-process figure of step 2.3.2 of the present invention；

Figure 10 is the sub-process figure of step 3.2 of the present invention；

Figure 11 is the sub-process figure of step 3.2.2 of the present invention；

Figure 12 is the sub-process figure of step 3.3 of the present invention；

Figure 13 is the sub-process figure of step 3.3.2 of the present invention；

Detailed description of the invention

Below in conjunction with the accompanying drawings the present invention is described in further details.

As shown in figure 1 to figure 13, the automatic identifying method bag of car plate frame in the preventing road monitoring system of the present invention Include following steps:

The first step, the original image that the resolution taken by preventing road monitoring system is 768 × 576 pixels is entered Row edge extracting, it is thus achieved that bianry image E, in bianry image E gray value be 1 point represent marginal point, ash Angle value be 0 point represent non-edge point, with the upper left corner of bianry image E as initial point, set up x-axis level to Right, y-axis pixel planes rectangular coordinate system straight down.

Second step, acquisition comprise the straight line set U of doubtful horizontal sides wire section₁, it specifically includes following sub-step Rapid:

Step 2.1: two scanning patterns on the cog region of definition isosceles triangle and horizontal direction:

Defining the cog region of horizontal isosceles triangle, the drift angle of this isosceles triangle is 30 degree and towards x-axis just Direction, the pixel (729,0) that the straight line at the place, base of isosceles triangle is perpendicular in x-axis.Isosceles three The center line of dihedral is parallel with x-axis.58 oblique line sections, described 58 oblique lines are also comprised in this isosceles triangle Duan Jun is with the drift angle of isosceles triangle as starting point, and base is terminal, and is positioned at coordinate system range described in step one Within.In this isosceles triangle in 61 line segments altogether including two stringcourses and a center line, arbitrarily The adjacent angle between two is 0.5 degree.

Choose with pixel a₁(40,40) are starting point with pixel a₇₂₈(729,40) are the line of terminal Section a, and choose with pixel (40,537) and be starting point and be the line of terminal with pixel (729,537) B is as the scanning pattern in two horizontal directions for section.The length of line segment a and line segment b is 690 pixels Point, and both is parallel with x-axis.

Step 2.2: the cog region drift angle of isosceles triangle is along the scanning recognition process of horizontal line section a, and it is concrete Including following sub-step:

Step 2.2.1: upper a certain to fixation by the drift angle of the cog region of horizontal isosceles triangle and line segment a Vegetarian refreshments overlaps, and corresponding with oblique line section by the abscissa value renewal array of current given pixel, oblique line section Linear equation.Its specific practice is:

Make the drift angle of the cog region of horizontal isosceles triangle described in step 2.1 and a certain given pixel on line segment a Point overlaps, and the sequence number of the drift angle position of the cog region of the most horizontal isosceles triangle is defined as a_n, its Middle n=x-39, in formula, x is the abscissa value that current corner place gives pixel.That is, horizontal isoceles triangle The drift angle of the cog region of shape is in starting point a of line segment a₁Time (40,40), the sequence number of drift angle position is also a₁.When the drift angle of cog region of horizontal isosceles triangle is at the terminal a of line segment a₆₉₀Time (729,40), drift angle The sequence number of position is a₆₉₀。

When the sequence number of the drift angle position of the cog region of horizontal isosceles triangle is a_nTime, define this isosceles three Serial number Fa of each bar oblique line section in dihedral_n-k(k sequentially takes 01,02,03 ... 61).Then Article 1 waist Serial number Fa of line_n-01, serial number Fa of center line_n-31, serial number Fa of another stringcourse_n-61.By oblique line section Fa_n-01On the coordinate figure of each pixel be all stored in line segment array data [a_n-01In], by same method, By other each oblique line section a_n-kOn the coordinate figure of each pixel be all stored in and this line segment sequence number Fa_n-k Corresponding line segment array data [a_n-k] in (k sequentially takes 01,02,03 ... 61).

Such as, the drift angle of the cog region of horizontal isosceles triangle is in starting point a of line segment a₁Time (40,40), Serial number a of each bar oblique line section in isosceles triangle_1-k(k sequentially takes 01,02,03 ... 61).Then Article one, serial number Fa of stringcourse_1-01, serial number Fa of center line_1-31, serial number Fa of another stringcourse_1-61.Will Oblique line section Fa_1-01On the coordinate figure of each pixel be all stored in line segment array data [a_1-01In], with same Method, by other each oblique line section a_1-kOn the coordinate figure of each pixel be all stored in and this line segment sequence Number a_1-kCorresponding line segment array data [a_1-k] in (k sequentially takes 01,02,03 ... 61).

Step 2.2.2: when completing the cog region drift angle current given coordinate points on horizontal line section a, to identification Whether each oblique line section in district has judgement identification and the screening of doubtful car plate frame line segment.It specifically wraps Include following sub-step:

Step 2.2.2.1: the drift angle of the cog region of horizontal isosceles triangle is in starting point a of line segment a₁(40,40) Time, select oblique line section Fa in current cog region_1-01。

Step 2.2.2.2: judge acquired by step 2.2.1 and oblique line section Fa_n-kCorresponding line segment array data[a_n-kIn], on a bit of line segment being made up of every 40 continuous image vegetarian refreshments, if at least 36 steps Marginal point described in rapid one, if having, then containing doubtful car plate frame line segment in this oblique line section, enters step 2.2.2.3.If no, then entering step 2.2.2.4.

Step 2.2.2.3: linea oblique anterior section Fa will be worked as_n-kLinear equation La corresponding under pixel coordinate system_n-kIt is stored in Array U₁, complete when linea oblique anterior section Fa_n-kThe identification screening of upper doubtful frame, and enter step 2.2.2.4.

Step 2.2.2.4: judge current line segment array data [a_n-k] (k sequentially takes 01,02,03 ... 61) In, whether k is 61, if k ≠ 61, then enters step 2.2.2.5.If k=61, then illustrate to have completed working as n During for some explicit value, to oblique line section Fa_n-01To Fa_n-61The identification screening of upper doubtful frame, and own With screened go out oblique line section Fa including car plate doubtful frame line segment_n-Linear equation La corresponding for k_n-k(k Sequentially take 01,02,03 ... 61) the most it is stored into array U₁In.Enter step 2.2.3.

Step 2.2.2.5: make k=k+1(k sequentially take 01,02,03 ... 61), update step 2.2.2.2 institute State oblique line section Fa_n-kAnd line segment array data [a corresponding thereto_n-k] sequence number, re-execute step 2.2.2.2 To step 2.2.2.4.

Step 2.2.3: make the drift angle of cog region of horizontal isosceles triangle from starting point a of line segment a₁(40,40) A pixel unit is sequentially moved horizontally, after each drift angle moves a new position, all to x-axis positive direction Update the drift angle a of the cog region of horizontal isosceles triangle described in step 2.2.2.1_n, and repeated execution of steps 2.2.2, Until the drift angle of the cog region of horizontal isosceles triangle moves the terminal a to line segment a₇₂₉Time (729,40), By a_nIt is updated to a₆₉₀, subsequently into step 2.3.

Step 2.3: by the cog region drift angle of isosceles triangle by the terminal a of the line segment a described in step 2.1₇₂₉ (729,40) change the starting point (40,537) to line segment b, and according to complete with the method as step 2.2 Becoming the cog region drift angle scanning recognition process along horizontal line section b of isosceles triangle, it specifically includes following son Step:

Step 2.3.1: upper a certain to fixation by the drift angle of the cog region of horizontal isosceles triangle and line segment b Vegetarian refreshments overlaps, and corresponding with oblique line section by the abscissa value renewal array of current given pixel, oblique line section Linear equation.Its specific practice is:

Make the drift angle of the cog region of horizontal isosceles triangle described in step 2.1 and a certain given pixel on line segment b Point overlaps, and the sequence number of the drift angle position of the cog region of the most horizontal isosceles triangle is defined as b_n, its Middle n=x-39, in formula, x is the abscissa value that current corner place gives pixel.That is, horizontal isoceles triangle The drift angle of the cog region of shape is in starting point b of line segment b₁Time (40,537), the sequence number of drift angle position is also b₁.When the drift angle of cog region of horizontal isosceles triangle is at the terminal b of line segment b₆₉₀Time (729,537), top The sequence number of position, angle is b₆₉₀。

When the sequence number of the drift angle position of the cog region of horizontal isosceles triangle is b_nTime, define this isosceles three Serial number Fb of each bar oblique line section in dihedral_n-k(k sequentially takes 01,02,03 ... 61).Then Article 1 waist Serial number Fb of line_n-01, serial number Fb of center line_n-31, serial number Fb of another stringcourse_n-61.By oblique line section Fb_n-01On the coordinate figure of each pixel be all stored in line segment array data [b_n-01In], by same method, By other each oblique line section b_n-kOn the coordinate figure of each pixel be all stored in and this line segment sequence number Fb_n-k Corresponding line segment array data [b_n-k] in (k sequentially takes 01,02,03 ... 61).

Such as, the drift angle of the cog region of horizontal isosceles triangle is in starting point b of line segment b₁Time (40,40), Serial number b of each bar oblique line section in isosceles triangle_1-k(k sequentially takes 01,02,03 ... 61).Then Article one, serial number Fb of stringcourse_1-01, serial number Fb of center line_1-31, serial number Fb of another stringcourse_1-61.Will Oblique line section Fb_1-01On the coordinate figure of each pixel be all stored in line segment array data [b_1-01In], with same Method, by other each oblique line section b_1-kOn the coordinate figure of each pixel be all stored in and this line segment sequence number b_1-kCorresponding line segment array data [b_1-k] in (k sequentially takes 01,02,03 ... 61).

Step 2.3.2: when completing the cog region drift angle current given coordinate points on horizontal line section b, to identification Whether each oblique line section in district has judgement identification and the screening of doubtful car plate frame line segment.It specifically wraps Include following sub-step:

Step 2.3.2.1: the drift angle of the cog region of horizontal isosceles triangle is in starting point b of line segment b₁(40,40) Time, select oblique line section Fb in current cog region_1-01。

Step 2.3.2.2: judge acquired by step 2.3.1 and oblique line section Fb_n-kCorresponding line segment array data[b_n-kIn], on a bit of line segment being made up of every 40 continuous image vegetarian refreshments, if at least 36 steps Marginal point described in rapid one, if having, then containing doubtful car plate frame line segment in this oblique line section, enters step 2.3.2.3.If no, then entering step 2.3.2.4.

Step 2.3.2.3: linea oblique anterior section Fb will be worked as_n-kLinear equation Lb corresponding under pixel coordinate system_n-kIt is stored in Array U₁, complete when linea oblique anterior section Fb_n-kThe identification screening of upper doubtful frame, and enter step 2.3.2.4.

Step 2.3.2.4: judge present segment array data [b_n-k] in (k sequentially takes 01,02,03 ... 61), Whether k is 61, if k ≠ 61, then enters step 2.3.2.5.If k=61, then illustrate to have completed to as n be During some explicit value, to oblique line section Fb_n-01To Fb_n-61The identification screening of upper doubtful frame, and all with Screened go out oblique line section Fb including car plate doubtful frame line segment_n-Linear equation Lb corresponding for k_n-k(k is suitable Secondary take 01,02,03 ... 61) the most it is stored into array U₁In.Enter step 2.3.3.

Step 2.3.2.5: make k=k+1(k sequentially take 01,02,03 ... 61), update step 2.3.2.2 institute State oblique line section Fb_n-kAnd line segment array data [b corresponding thereto_n-k] sequence number, re-execute step 2.3.2.2 To step 2.3.2.4.

Step 2.3.3: make the drift angle of cog region of horizontal isosceles triangle from starting point b of line segment b₁(40,537) A pixel unit is sequentially moved horizontally, after each drift angle moves a new position, all to x-axis positive direction Update the drift angle b of the cog region of horizontal isosceles triangle described in step 2.3.2.1_n, and repeated execution of steps 2.3.2, Until the drift angle of the cog region of horizontal isosceles triangle moves the terminal b to line segment b₇₂₉Time (729,40), By b_nIt is updated to b₆₉₀, complete the cog region drift angle scanning recognition process along horizontal line section b of isosceles triangle, Subsequently into step 3.

Step 3, acquisition comprise the straight line set U of doubtful vertical edge wire section₂, it specifically includes following sub-step Rapid: step 3.1: two scanning patterns on the cog region of definition isosceles triangle and vertical direction:

Defining the cog region of vertical isosceles triangle, the drift angle of this isosceles triangle is 30 degree and towards y-axis just Direction, the pixel (0,537) that the straight line at the place, base of isosceles triangle is perpendicular in y-axis.Isosceles three The center line of dihedral is parallel with y-axis.58 oblique line sections, described 58 oblique lines are also comprised in this isosceles triangle Duan Jun is with the drift angle of isosceles triangle as starting point, and base is terminal, and is positioned at coordinate system range described in step one Within.In this isosceles triangle in 61 line segments altogether including two stringcourses and a center line, arbitrarily The adjacent angle between two is 0.5 degree.

Choosing with pixel (40,40) is starting point with the line segment c that pixel (40,537) is terminal, And choose with pixel (729,40) and be starting point and make with line segment d that pixel (729,537) is terminal It it is the scanning pattern on two vertical directions.The length of line segment c and line segment d is 498 pixels, and Both is parallel with y-axis.

Step 3.2: the cog region drift angle of isosceles triangle is along the scanning recognition process of vertical line segment c, and it is concrete Including following sub-step:

Step 3.2.1: upper a certain to fixation by the drift angle of the cog region of vertical isosceles triangle and line segment c Vegetarian refreshments overlaps, and corresponding with oblique line section by the abscissa value renewal array of current given pixel, oblique line section Linear equation.Its specific practice is:

Make the drift angle of the cog region of vertical isosceles triangle described in step 3.1 and a certain given pixel on line segment c Point overlaps, and the sequence number of the now drift angle position of the cog region of vertical isosceles triangle is defined as c_n, its Middle n=y-39, in formula, y is the ordinate value that current corner place gives pixel.That is, vertical isoceles triangle The drift angle of the cog region of shape is in starting point c of line segment c₁Time (40,40), the sequence number of drift angle position is also c₁.When the drift angle of cog region of vertical isosceles triangle is at the terminal c of line segment c₄₉₈Time (40,537), drift angle The sequence number of position is c₄₉₈。

When the sequence number of the drift angle position of the cog region of vertical isosceles triangle is c_nTime, define this isosceles three Serial number Fc of each bar oblique line section in dihedral_n-k(k sequentially takes 01,02,03 ... 61).Then Article 1 waist Serial number Fc of line_n-01, serial number Fc of center line_n-31, serial number Fc of another stringcourse_n-61.By oblique line section Fc_n-01On the coordinate figure of each pixel be all stored in line segment array data [c_n-01In], by same method, By other each oblique line section c_n-kOn the coordinate figure of each pixel be all stored in and this line segment sequence number Fc_n-k Corresponding line segment array data [c_n-k] in (k sequentially takes 01,02,03 ... 61).

Such as, the drift angle of the cog region of vertical isosceles triangle is in starting point c of line segment c₁Time (40,40), Serial number c of each bar oblique line section in isosceles triangle_1-k(k sequentially takes 01,02,03 ... 61).Then Article one, serial number Fc of stringcourse_1-01, serial number Fc of center line_1-31, serial number Fc of another stringcourse_1-61.Will Oblique line section Fc_1-01On the coordinate figure of each pixel be all stored in line segment array data [c_1-01In], with same Method, by other each oblique line section c_1-kOn the coordinate figure of each pixel be all stored in and this line segment sequence Number c_1-kCorresponding line segment array data [c_1-k] in (k sequentially takes 01,02,03 ... 61).

Step 3.2.2: when completing the cog region drift angle current given coordinate points on vertical line segment c, to identification Whether each oblique line section in district has judgement identification and the screening of doubtful car plate frame line segment.It specifically wraps Include following sub-step:

Step 3.2.2.1: vertically the drift angle of the cog region of isosceles triangle is in starting point c of line segment c₁(40,40) Time, select oblique line section Fc in current cog region_1-01。

Step 3.2.2.2: judge acquired by step 3.2.1 and oblique line section Fc_n-kCorresponding line segment array data[c_n-kIn], on a bit of line segment being made up of every 40 continuous image vegetarian refreshments, if at least 36 steps Marginal point described in rapid one, if having, then containing doubtful car plate frame line segment in this oblique line section, enters step 3.2.2.3.If no, then entering step 3.2.2.4.

Step 3.2.2.3: linea oblique anterior section Fc will be worked as_n-kLinear equation Lc corresponding under pixel coordinate system_n-kIt is stored in Array U₂, complete when linea oblique anterior section Fc_n-kThe identification screening of upper doubtful frame, and enter step 3.2.2.4.

Step 3.2.2.4: judge current line segment array data [c_n-k] (k sequentially takes 01,02,03 ... 61) In, whether k is 61, if k ≠ 61, then enters step 3.2.2.5.If k=61, then illustrate to have completed working as n During for some explicit value, to oblique line section Fc_n-01To Fc_n-61The identification screening of upper doubtful frame, and own With screened go out oblique line section Fc including car plate doubtful frame line segment_n-Linear equation Lc corresponding for k_n-k(k Sequentially take 01,02,03 ... 61) the most it is stored into array U₂In.Enter step 3.2.3.

Step 3.2.2.5: make k=k+1(k sequentially take 01,02,03 ... 61), update step 3.2.2.2 institute State oblique line section Fc_n-kAnd line segment array data [c corresponding thereto_n-k] sequence number, re-execute step 3.2.2.2 To step 3.2.2.4.

Step 3.2.3: make the drift angle of cog region of vertical isosceles triangle from starting point c of line segment c₁(40,40) A pixel unit is the most vertically moved, after each drift angle moves a new position, all to y-axis positive direction Update the drift angle c of the vertically cog region of isosceles triangle described in step 3.2.2.1_n, and repeated execution of steps 3.2.2, Until vertically the drift angle of the cog region of isosceles triangle moves the terminal c to line segment c₄₉₈Time (40,537), By c_nIt is updated to c₄₉₈, subsequently into step 3.3.

Step 3.3: by the cog region drift angle of isosceles triangle by the terminal c of the line segment c described in step 3.1₄₉₈ (40,537) change the starting point (729,40) to line segment d, and according to complete with the method as step 3.2 Becoming the cog region drift angle scanning recognition process along vertical line segment d of isosceles triangle, it specifically includes following son Step:

Step 3.3.1: upper a certain to fixation by the drift angle of the cog region of vertical isosceles triangle and line segment d Vegetarian refreshments overlaps, and corresponding with oblique line section by the ordinate value renewal array of current given pixel, oblique line section Linear equation.Its specific practice is:

Make the drift angle of the cog region of vertical isosceles triangle described in step 3.1 and a certain given pixel on line segment d Point overlaps, and the sequence number of the now drift angle position of the cog region of vertical isosceles triangle is defined as d_n, its Middle n=y-39, in formula, y is the ordinate value that current corner place gives pixel.That is, vertical isoceles triangle The drift angle of the cog region of shape is in starting point d of line segment d₁Time (729,40), the sequence number of drift angle position is also d₁.When the drift angle of cog region of vertical isosceles triangle is at the terminal d of line segment d₆₉₀Time (729,537), top The sequence number of position, angle is d₄₉₈。

When the sequence number of the drift angle position of the cog region of vertical isosceles triangle is d_nTime, define this isosceles three Serial number Fd of each bar oblique line section in dihedral_n-k(k sequentially takes 01,02,03 ... 61).Then Article 1 waist Serial number Fd of line_n-01, serial number Fd of center line_n-31, serial number Fd of another stringcourse_n-61.By oblique line section Fd_n-01On the coordinate figure of each pixel be all stored in line segment array data [d_n-01In], by same method, By other each oblique line section d_n-kOn the coordinate figure of each pixel be all stored in and this line segment sequence number Fd_n-k Corresponding line segment array data [d_n-k] in (k sequentially takes 01,02,03 ... 61).

Such as, the drift angle of the cog region of vertical isosceles triangle is in starting point d of line segment d₁Time (40,40), Serial number d of each bar oblique line section in isosceles triangle_1-k(k sequentially takes 01,02,03 ... 61).Then Article one, serial number Fd of stringcourse_1-01, serial number Fd of center line_1-31, serial number Fd of another stringcourse_1-61.Will Oblique line section Fd_1-01On the coordinate figure of each pixel be all stored in line segment array data [d_1-01In], with same Method, by other each oblique line section d_1-kOn the coordinate figure of each pixel be all stored in and this line segment sequence number d_1-kCorresponding line segment array data [d_1-k] in (k sequentially takes 01,02,03 ... 61).

Step 3.3.2: when completing the cog region drift angle current given coordinate points on vertical line segment d, to identification Whether each oblique line section in district has judgement identification and the screening of doubtful car plate frame line segment.It specifically wraps Include following sub-step:

Step 3.3.2.1: vertically the drift angle of the cog region of isosceles triangle is in starting point d of line segment d₁(729,40) Time, select oblique line section Fd in current cog region_1-01。

Step 3.3.2.2: judge acquired by step 3.3.1 and oblique line section Fd_n-kCorresponding line segment array data[d_n-kIn], on a bit of line segment being made up of every 40 continuous image vegetarian refreshments, if at least 36 steps Marginal point described in rapid one, if having, then containing doubtful car plate frame line segment in this oblique line section, enters step 3.3.2.3.If no, then entering step 3.3.2.4.

Step 3.3.2.3: linea oblique anterior section Fd will be worked as_n-kLinear equation Ld corresponding under pixel coordinate system_n-kIt is stored in Array U₂, complete when linea oblique anterior section Fd_n-kThe identification screening of upper doubtful frame, and enter step 3.3.2.4.

Step 3.3.2.4: judge present segment array data [d_n-k] in (k sequentially takes 01,02,03 ... 61), Whether k is 61, if k ≠ 61, then enters step 3.3.2.5.If k=61, then illustrate to have completed to as n be During some explicit value, to oblique line section Fd_n-01To Fd_n-61The identification screening of upper doubtful frame, and all with Screened go out oblique line section Fd including car plate doubtful frame line segment_n-Linear equation Ld corresponding for k_n-k(k is suitable Secondary take 01,02,03 ... 61) the most it is stored into array U₂In.Enter step 3.3.3.

Step 3.3.2.5: make k=k+1(k sequentially take 01,02,03 ... 61), update step 3.3.2.2 institute State oblique line section Fd_n-kAnd line segment array data [d corresponding thereto_n-k] sequence number, re-execute step 3.3.2.2 To step 3.3.2.4.

Step 3.3.3: make the drift angle of cog region of vertical isosceles triangle from starting point d of line segment d₁(729,40) A pixel unit is the most vertically moved, after each drift angle moves a new position, all to y-axis positive direction Update the drift angle d of the vertically cog region of isosceles triangle described in step 3.3.2.1_n, and repeated execution of steps 3.3.2, Until vertically the drift angle of the cog region of isosceles triangle moves the terminal d to line segment d₄₉₈Time (729,537), By d_nIt is updated to d₄₉₈, complete the cog region drift angle scanning recognition process along vertical line segment d of isosceles triangle, Subsequently into step 4.

Step 4: straight line set U described in read step two respectively₁With straight line set U described in step 3₂, and sentence Disconnected logical formula U₁&U₂Result, if its result is true, then enter step 5, if its result is false, the most directly Connect the identification process terminating this method.

Step 5: according to the slope result of product of two intersecting straight lines, it is judged that whether meet both it and hang down each other Straight condition, from U₁Middle screening retains energy and U₂In the most vertical straight line of two straight lines, by qualified Straight line is stored in set U₃, subsequently into step 6.

Step 6: according to the slope result of product of two intersecting straight lines, it is judged that whether meet both it and hang down each other Straight condition, from U₂Middle screening retains energy and U₃In the most vertical straight line of two straight lines, by qualified Straight line is stored in set U₄, subsequently into step 7.

Step 7: according to the slope result of product of two intersecting straight lines, it is judged that whether meet both it and hang down each other Straight condition, it is judged that set U₄In whether have two straight lines can simultaneously and U₃In two straight lines vertical, then Enter step 8.

Step 8: obtained the linear equation of rectangle four edges line by step 7 respectively, the four edges line of this rectangle It is the car plate doubtful boundary line in photo.

The slope result of product according to two intersecting straight lines described in step 5 or step 6 or step 7, sentences Disconnected whether meet condition perpendicular to one another both it criterion be:

Any two linear equations are denoted as respectively: straight line 1:y₁=k₁x+b₁.Straight line 2:y₂=k₂x+b₂.Then Judgement formula: E=k can be obtained₁×k₂。

If the result value of E is in interval [-1.05 ,-0.95], then it is assumed that two straight lines are perpendicular to one another.

Claims (2)

1. the automatic identifying method of car plate frame in preventing road monitoring system, it is characterised in that the method include as Lower step:

The first step, the original image that the resolution taken by preventing road monitoring system is 768 × 576 pixels is entered Row edge extracting, it is thus achieved that bianry image E, in bianry image E gray value be 1 point represent marginal point, ash Angle value be 0 point represent non-edge point, with the upper left corner of bianry image E as initial point, set up x-axis level to Right, y-axis pixel planes rectangular coordinate system straight down；

Second step, acquisition comprise the straight line set U of doubtful horizontal sides wire section₁, it specifically includes following sub-step Rapid:

Step 2.1: two scanning patterns on the cog region of definition isosceles triangle and horizontal direction:

Defining the cog region of horizontal isosceles triangle, the drift angle of this isosceles triangle is 30 degree and towards x-axis just Direction, the pixel (729,0) that the straight line at the place, base of isosceles triangle is perpendicular in x-axis；Isosceles three The center line of dihedral is parallel with x-axis；58 oblique line sections, described 58 oblique lines are also comprised in this isosceles triangle Duan Jun is with the drift angle of isosceles triangle as starting point, and base is terminal, and is positioned at coordinate system range described in step one Within；In this isosceles triangle in 61 line segments altogether including two stringcourses and a center line, arbitrarily The adjacent angle between two is 0.5 degree；

Choose with pixel a₁(40,40) are starting point with pixel a₇₂₈(729,40) are the line of terminal Section a, and choose with pixel (40,537) and be starting point and be the line of terminal with pixel (729,537) B is as the scanning pattern in two horizontal directions for section；The length of line segment a and line segment b is 690 pixels Point, and both is parallel with x-axis；

Step 2.2: the cog region drift angle of isosceles triangle is along the scanning recognition process of horizontal line section a, and it is concrete Including following sub-step:

Step 2.2.1: upper a certain to fixation by the drift angle of the cog region of horizontal isosceles triangle and line segment a Vegetarian refreshments overlaps, and corresponding with oblique line section by the abscissa value renewal array of current given pixel, oblique line section Linear equation；Its specific practice is:

Make the drift angle of the cog region of horizontal isosceles triangle described in step 2.1 and a certain given pixel on line segment a Point overlaps, and the sequence number of the drift angle position of the cog region of the most horizontal isosceles triangle is defined as a_n, its Middle n=x-39, in formula, x is the abscissa value that current corner place gives pixel；

When the sequence number of the drift angle position of the cog region of horizontal isosceles triangle is a_nTime, define this isosceles three Serial number Fa of each bar oblique line section in dihedral_n-k, k sequentially takes 01,02,03 ... 61；By oblique line section Fa_n-01 On the coordinate figure of each pixel be all stored in line segment array data [a_n-01In], by same method, by it Its each oblique line section a_n-kOn the coordinate figure of each pixel be all stored in and this line segment sequence number Fa_n-kCorresponding Line segment array data [a_n-kIn], k sequentially takes 01,02,03 ... 61；

Step 2.2.2: when completing the cog region drift angle current given coordinate points on horizontal line section a, to identification Whether each oblique line section in district has judgement identification and the screening of doubtful car plate frame line segment；It specifically wraps Include following sub-step:

Step 2.2.2.1: the drift angle of the cog region of horizontal isosceles triangle is in starting point a of line segment a₁(40,40) Time, select oblique line section Fa in current cog region_1-01；

Step 2.2.2.2: judge acquired by step 2.2.1 and oblique line section Fa_n-kCorresponding line segment array data[a_n-kIn], on a bit of line segment being made up of every 40 continuous image vegetarian refreshments, if at least 36 steps Marginal point described in rapid one, if having, then containing doubtful car plate frame line segment in this oblique line section, enters step 2.2.2.3；If no, then entering step 2.2.2.4；

Step 2.2.2.3: linea oblique anterior section Fa will be worked as_n-kLinear equation La corresponding under pixel coordinate system_n-kIt is stored in Array U₁, complete when linea oblique anterior section Fa_n-kThe identification screening of upper doubtful frame, and enter step 2.2.2.4；

Step 2.2.2.4: judge current line segment array data [a_n-kIn], k sequentially takes 01,02,03 ... 61, Whether k is 61, if k ≠ 61, then enters step 2.2.2.5；If k=61, then enter step 2.2.3；

Step 2.2.2.5: make k=k+1, k sequentially take 01,02,03 ... 61, updates step 2.2.2.2 institute State oblique line section Fa_n-kAnd line segment array data [a corresponding thereto_n-k] sequence number, re-execute step 2.2.2.2 To step 2.2.2.4；

Step 2.2.3: make the drift angle of cog region of horizontal isosceles triangle from starting point a of line segment a₁(40,40) A pixel unit is sequentially moved horizontally, after each drift angle moves a new position, all to x-axis positive direction Update the drift angle a of the cog region of horizontal isosceles triangle described in step 2.2.2.1_n, and repeated execution of steps 2.2.2, Until the drift angle of the cog region of horizontal isosceles triangle moves the terminal a to line segment a₇₂₉Time (729,40), By a_nIt is updated to a₆₉₀, subsequently into step 2.3；

Step 2.3: by the cog region drift angle of isosceles triangle by the terminal a of the line segment a described in step 2.1₇₂₉ (729,40) change the starting point (40,537) to line segment b, and according to complete with the method as step 2.2 Becoming the cog region drift angle scanning recognition process along horizontal line section b of isosceles triangle, it specifically includes following son Step:

Step 2.3.1: upper a certain to fixation by the drift angle of the cog region of horizontal isosceles triangle and line segment b Vegetarian refreshments overlaps, and corresponding with oblique line section by the abscissa value renewal array of current given pixel, oblique line section Linear equation；Its specific practice is:

Make the drift angle of the cog region of horizontal isosceles triangle described in step 2.1 and a certain given pixel on line segment b Point overlaps, and the sequence number of the drift angle position of the cog region of the most horizontal isosceles triangle is defined as b_n, its Middle n=x-39, in formula, x is the abscissa value that current corner place gives pixel；

When the sequence number of the drift angle position of the cog region of horizontal isosceles triangle is b_nTime, define this isosceles three Serial number Fb of each bar oblique line section in dihedral_n-k, k sequentially takes 01,02,03 ... 61；By oblique line section Fb_n-01 On the coordinate figure of each pixel be all stored in line segment array data [b_n-01In], by same method, by it Its each oblique line section b_n-kOn the coordinate figure of each pixel be all stored in and this line segment sequence number Fb_n-kCorresponding Line segment array data [b_n-kIn], k sequentially takes 01,02,03 ... 61；

Step 2.3.2: when completing the cog region drift angle current given coordinate points on horizontal line section b, to identification Whether each oblique line section in district has judgement identification and the screening of doubtful car plate frame line segment；It specifically wraps Include following sub-step:

Step 2.3.2.1: the drift angle of the cog region of horizontal isosceles triangle is in starting point b of line segment b₁(40,40) Time, select oblique line section Fb in current cog region_1-01；

Step 2.3.2.2: judge acquired by step 2.3.1 and oblique line section Fb_n-kCorresponding line segment array data[b_n-kIn], on a bit of line segment being made up of every 40 continuous image vegetarian refreshments, if at least 36 steps Marginal point described in rapid one, if having, then containing doubtful car plate frame line segment in this oblique line section, enters step 2.3.2.3；If no, then entering step 2.3.2.4；

Step 2.3.2.3: linea oblique anterior section Fb will be worked as_n-kLinear equation Lb corresponding under pixel coordinate system_n-kIt is stored in Array U₁, complete when linea oblique anterior section Fb_n-kThe identification screening of upper doubtful frame, and enter step 2.3.2.4；

Step 2.3.2.4: judge present segment array data [b_n-k] in (k sequentially takes 01,02,03 ... 61), Whether k is 61, if k ≠ 61, then enters step 2.3.2.5；If k=61, then enter step 2.3.3；

Step 2.3.2.5: make k=k+1, k sequentially take 01,02,03 ... 61, updates step 2.3.2.2 institute State oblique line section Fb_n-kAnd line segment array data [b corresponding thereto_n-k] sequence number, re-execute step 2.3.2.2 To step 2.3.2.4；

Step 2.3.3: make the drift angle of cog region of horizontal isosceles triangle from starting point b of line segment b₁(40,537) A pixel unit is sequentially moved horizontally, after each drift angle moves a new position, all to x-axis positive direction Update the drift angle b of the cog region of horizontal isosceles triangle described in step 2.3.2.1_n, and repeated execution of steps 2.3.2, Until the drift angle of the cog region of horizontal isosceles triangle moves the terminal b to line segment b₇₂₉Time (729,40), By b_nIt is updated to b₆₉₀, complete the cog region drift angle scanning recognition process along horizontal line section b of isosceles triangle, Subsequently into step 3；

Step 3, acquisition comprise the straight line set U of doubtful vertical edge wire section₂, it specifically includes following sub-step Rapid: step 3.1: two scanning patterns on the cog region of definition isosceles triangle and vertical direction:

Defining the cog region of vertical isosceles triangle, the drift angle of this isosceles triangle is 30 degree and towards y-axis just Direction, the pixel (0,537) that the straight line at the place, base of isosceles triangle is perpendicular in y-axis；Isosceles three The center line of dihedral is parallel with y-axis；58 oblique line sections, described 58 oblique lines are also comprised in this isosceles triangle Duan Jun is with the drift angle of isosceles triangle as starting point, and base is terminal, and is positioned at coordinate system range described in step one Within；In this isosceles triangle in 61 line segments altogether including two stringcourses and a center line, arbitrarily The adjacent angle between two is 0.5 degree；

Choosing with pixel (40,40) is starting point with the line segment c that pixel (40,537) is terminal, And choose with pixel (729,40) and be starting point and make with line segment d that pixel (729,537) is terminal It it is the scanning pattern on two vertical directions；The length of line segment c and line segment d is 498 pixels, and Both is parallel with y-axis；

Step 3.2: the cog region drift angle of isosceles triangle is along the scanning recognition process of vertical line segment c, and it is concrete Including following sub-step:

Step 3.2.1: upper a certain to fixation by the drift angle of the cog region of vertical isosceles triangle and line segment c Vegetarian refreshments overlaps, and corresponding with oblique line section by the abscissa value renewal array of current given pixel, oblique line section Linear equation；Its specific practice is:

Make the drift angle of the cog region of vertical isosceles triangle described in step 3.1 and a certain given pixel on line segment c Point overlaps, and the sequence number of the now drift angle position of the cog region of vertical isosceles triangle is defined as c_n, its Middle n=y-39, in formula, y is the ordinate value that current corner place gives pixel；

When the sequence number of the drift angle position of the cog region of vertical isosceles triangle is c_nTime, define this isosceles three Serial number Fc of each bar oblique line section in dihedral_n-k, k sequentially takes 01,02,03 ... 61；By oblique line section Fc_n-01 On the coordinate figure of each pixel be all stored in line segment array data [c_n-01In], by same method, by it Its each oblique line section c_n-kOn the coordinate figure of each pixel be all stored in and this line segment sequence number Fc_n-kCorresponding Line segment array data [c_n-kIn], k sequentially takes 01,02,03 ... 61；

Step 3.2.2: when completing the cog region drift angle current given coordinate points on vertical line segment c, to identification Whether each oblique line section in district has judgement identification and the screening of doubtful car plate frame line segment；It specifically wraps Include following sub-step:

Step 3.2.2.1: vertically the drift angle of the cog region of isosceles triangle is in starting point c of line segment c₁(40,40) Time, select oblique line section Fc in current cog region_1-01；

Step 3.2.2.2: judge acquired by step 3.2.1 and oblique line section Fc_n-kCorresponding line segment array data[c_n-kIn], on a bit of line segment being made up of every 40 continuous image vegetarian refreshments, if at least 36 steps Marginal point described in rapid one, if having, then containing doubtful car plate frame line segment in this oblique line section, enters step 3.2.2.3；If no, then entering step 3.2.2.4；

Step 3.2.2.3: linea oblique anterior section Fc will be worked as_n-kLinear equation Lc corresponding under pixel coordinate system_n-kIt is stored in Array U₂, complete when linea oblique anterior section Fc_n-kThe identification screening of upper doubtful frame, and enter step 3.2.2.4；

Step 3.2.2.4: judge current line segment array data [c_n-kIn], k sequentially takes 01,02,03 ... 61, Whether k is 61, if k ≠ 61, then enters step 3.2.2.5；If k=61, then enter step 3.2.3；

Step 3.2.2.5: make k=k+1, k sequentially take 01,02,03 ... 61, updates step 3.2.2.2 institute State oblique line section Fc_n-kAnd line segment array data [c corresponding thereto_n-k] sequence number, re-execute step 3.2.2.2 To step 3.2.2.4；

Step 3.2.3: make the drift angle of cog region of vertical isosceles triangle from starting point c of line segment c₁(40,40) A pixel unit is the most vertically moved, after each drift angle moves a new position, all to y-axis positive direction Update the drift angle c of the vertically cog region of isosceles triangle described in step 3.2.2.1_n, and repeated execution of steps 3.2.2, Until vertically the drift angle of the cog region of isosceles triangle moves the terminal c to line segment c₄₉₈Time (40,537), By c_nIt is updated to c₄₉₈, subsequently into step 3.3；

Step 3.3: by the cog region drift angle of isosceles triangle by the terminal c of the line segment c described in step 3.1₄₉₈ (40,537) change the starting point (729,40) to line segment d, and according to complete with the method as step 3.2 Becoming the cog region drift angle scanning recognition process along vertical line segment d of isosceles triangle, it specifically includes following son Step:

Step 3.3.1: upper a certain to fixation by the drift angle of the cog region of vertical isosceles triangle and line segment d Vegetarian refreshments overlaps, and corresponding with oblique line section by the ordinate value renewal array of current given pixel, oblique line section Linear equation；Its specific practice is:

Make the drift angle of the cog region of vertical isosceles triangle described in step 3.1 and a certain given pixel on line segment d Point overlaps, and the sequence number of the now drift angle position of the cog region of vertical isosceles triangle is defined as d_n, its Middle n=y-39, in formula, y is the ordinate value that current corner place gives pixel；

When the sequence number of the drift angle position of the cog region of vertical isosceles triangle is d_nTime, define this isosceles three Serial number Fd of each bar oblique line section in dihedral_n-k, k sequentially takes 01,02,03 ... 61；By oblique line section Fd_n-01 On the coordinate figure of each pixel be all stored in line segment array data [d_n-01In], by same method, by it Its each oblique line section d_n-kOn the coordinate figure of each pixel be all stored in and this line segment sequence number Fd_n-kCorresponding Line segment array data [d_n-kIn], k sequentially takes 01,02,03 ... 61；

Step 3.3.2: when completing the cog region drift angle current given coordinate points on vertical line segment d, to identification Whether each oblique line section in district has judgement identification and the screening of doubtful car plate frame line segment；It specifically wraps Include following sub-step:

Step 3.3.2.1: vertically the drift angle of the cog region of isosceles triangle is in starting point d of line segment d₁(729,40) Time, select oblique line section Fd in current cog region_1-01；

Step 3.3.2.2: judge acquired by step 3.3.1 and oblique line section Fd_n-kCorresponding line segment array data[d_n-kIn], on a bit of line segment being made up of every 40 continuous image vegetarian refreshments, if at least 36 steps Marginal point described in rapid one, if having, then containing doubtful car plate frame line segment in this oblique line section, enters step 3.3.2.3；If no, then entering step 3.3.2.4；

Step 3.3.2.3: linea oblique anterior section Fd will be worked as_n-kLinear equation Ld corresponding under pixel coordinate system_n-kIt is stored in Array U₂, complete when linea oblique anterior section Fd_n-kThe identification screening of upper doubtful frame, and enter step 3.3.2.4；

Step 3.3.2.4: judge present segment array data [d_n-kIn], k sequentially takes 01,02,03 ... 61, Whether k is 61, if k ≠ 61, then enters step 3.3.2.5；If k=61, then enter step 3.3.3；

Step 3.3.2.5: make k=k+1, k sequentially take 01,02,03 ... 61, updates step 3.3.2.2 institute State oblique line section Fd_n-kAnd line segment array data [d corresponding thereto_n-k] sequence number, re-execute step 3.3.2.2 To step 3.3.2.4；

Step 3.3.3: make the drift angle of cog region of vertical isosceles triangle from starting point d of line segment d₁(729,40) A pixel unit is the most vertically moved, after each drift angle moves a new position, all to y-axis positive direction Update the drift angle d of the vertically cog region of isosceles triangle described in step 3.3.2.1_n, and repeated execution of steps 3.3.2, Until vertically the drift angle of the cog region of isosceles triangle moves the terminal d to line segment d₄₉₈Time (729,537), By d_nIt is updated to d₄₉₈, complete the cog region drift angle scanning recognition process along vertical line segment d of isosceles triangle, Subsequently into step 4；

Step 4: straight line set U described in read step two respectively₁With straight line set U described in step 3₂, and sentence Disconnected logical formula U₁&U₂Result, if its result is true, then enter step 5, if its result is false, the most directly Connect the identification process terminating this method；

Step 5: according to the slope result of product of two intersecting straight lines, it is judged that whether meet both it and hang down each other Straight condition, from U₁Middle screening retains energy and U₂In the most vertical straight line of two straight lines, by qualified Straight line is stored in set U₃, subsequently into step 6；

Step 6: according to the slope result of product of two intersecting straight lines, it is judged that whether meet both it and hang down each other Straight condition, from U₂Middle screening retains energy and U₃In the most vertical straight line of two straight lines, by qualified Straight line is stored in set U₄, subsequently into step 7；

Step 7: according to the slope result of product of two intersecting straight lines, it is judged that whether meet both it and hang down each other Straight condition, it is judged that set U₄In whether have two straight lines can simultaneously and U₃In two straight lines vertical, then Enter step 8；

Step 8: obtained the linear equation of rectangle four edges line by step 7 respectively, the four edges line of this rectangle It is the car plate doubtful boundary line in photo.

The automatic identifying method of car plate frame in preventing road monitoring system the most according to claim 1, it is special Levy and be, the slope result of product according to two intersecting straight lines described in step 5 or step 6 or step 7, Judge that the criterion whether meeting condition perpendicular to one another both it is:

Any two linear equations are denoted as respectively: straight line 1:y₁=k₁x+b₁；Straight line 2:y₂=k₂x+b₂；Then Judgement formula: E=k can be obtained₁×k₂；

If the result value of E is in interval [-1.05 ,-0.95], then it is assumed that two straight lines are perpendicular to one another.