CN109427238A

CN109427238A - A kind of Road letterings labeling position determines method and device

Info

Publication number: CN109427238A
Application number: CN201710786679.5A
Authority: CN
Inventors: 柴艳瑞; 王海鹏; 苏向奎; 王前卫
Original assignee: Autonavi Information Technology Co Ltd
Current assignee: Alibaba China Co Ltd
Priority date: 2017-09-04
Filing date: 2017-09-04
Publication date: 2019-03-05
Anticipated expiration: 2037-09-04
Also published as: CN109427238B

Abstract

This application discloses a kind of Road letterings labeling positions to determine method and device, the application quickly judges that electronic map to be shown covers geographical coverage area with the presence or absence of the road for constituting navigation routine by way of the intersection judgement of region, and the labeling position of text to be marked is determined according to the shape point set of road in the case where determining intersection, it avoids the occurrence of and calculates Road letterings labeling position for not shown road, the problem of to cause computing resource waste, computing resource is greatly saved.

Description

A kind of Road letterings labeling position determines method and device

Technical field

This application involves electronic map Rendering fields, true more specifically to a kind of Road letterings labeling position Determine method and device.

Background technique

Road letterings mark is a key content of map denotation, and the quality of Road letterings mark directly affects user's Experience, is an important ring for software quality assurance.The objective of Road letterings mark is that suitable position is found on map to road Road carries out label character.

The mode of existing road label character is usually road data required for server-side tissue client, including group Shape point set and text to be marked at road to be marked, client calculates the length of text to be marked, and traverses shape point Set finds the position for placing text to be marked enough, and then marks.But in some cases, road to be marked does not exist In client electronic map overlay area to be shown, so that the prior art expends the time and is calculated after labeling position, and It does not need to be labeled in electronic map, causes to waste computing resource.

Summary of the invention

In view of this, this application provides a kind of Road letterings labeling positions to determine method and device, it is existing for solving Technology is for the problem that not shown route calculation Road letterings labeling position, to cause waste computing resource.

To achieve the goals above, it is proposed that scheme it is as follows:

A kind of Road letterings labeling position determines method, comprising:

Judge whether electronic map to be shown is identical as the geographic area for the electronic map covering having been displayed, it is described to have shown A bar navigation route is illustrated on the electronic map shown, if it is different, then obtaining the geographic region of electronic map covering to be shown Domain range；

Judge the geographical coverage area of the electronic map covering to be shown and the geographic region of navigation routine covering Whether domain range intersects, if intersection determines the road according to the shape point set for the road for constituting the navigation routine Labeling position of the text to be marked in the electronic map to be shown.

Preferably, the method further includes:

Obtain the map zoom levels of electronic map to be shown and the line width information of the road；

According to the line width information of the map zoom levels and the road, in the shape point set of the road Shape point is vacuated, and the shape point set for vacuating rear road is obtained.

Preferably, the line width information according to the map zoom levels and the road, to the shape of the road Shape point in shape point set is vacuated, and the shape point set for vacuating rear road is obtained, comprising:

According to the line width information of the map zoom levels and the road, obtain the road vacuates jump point threshold Value；

Successively choose a shape point from the shape point set of the road, calculate the shape point of the selection with it is next adjacent The distance of shape point；

The map zoom levels are compared with the map zoom levels threshold value of setting, if the map zoom levels Greater than setting map level of zoom threshold value, then judge the distance whether be more than it is described vacuate jump point threshold value, if so, retaining institute The shape point of selection is stated, if it is not, then the shape point by the selection vacuates；

The shape point of reservation constitutes the shape point set for vacuating rear road.

Preferably, each shape point is provided with and vacuates label, this method in the shape point set further include:

If the map zoom levels are no more than the setting map level of zoom threshold value, the shape of the selection is judged The value for vacuating label of point indicates whether that this is vacuated labeled as effective；

If indicating, this is vacuated labeled as effectively, and the shape point of the selection is vacuated；

If indicating, this is vacuated labeled as invalid, judge the distance whether be more than it is described vacuate jump point threshold value, if so, Retain the shape point of the selection, if it is not, then the shape point by the selection vacuates；

Preferably, the line width information according to the map zoom levels and the road, obtains the road Vacuate jump point threshold value, comprising:

Obtain that the map zoom levels are corresponding to vacuate jump point threshold calculations formula；

According to the line width for vacuating jump point threshold calculations formula and road of acquisition, calculating vacuates jump point threshold value.

Preferably, the shape point set according to the road for constituting the navigation routine, determine the road wait mark Labeling position of the explanatory notes word in the electronic map to be shown, comprising:

According to the position of shape point in the shape point set for the road for constituting the navigation routine, one section of continuous mesh is obtained Shape point is marked, the target shape point constitutes the target road section for marking the text to be marked of the road, the target road The length of section meets not less than the length and tortuous of the text to be marked sets tortuous condition；

In the target road section, the section that can mark the text to be marked of the road is obtained, as the road The labeling position of text to be marked.

Preferably, in the shape point set according to the road for constituting the navigation routine shape point position, obtain One section of continuous target shape point, the target shape point constitute the target road for marking the text to be marked of the road Section, comprising:

According to the position of shape point and the electricity to be shown in the shape point set for the road for constituting the navigation routine The shape point of the road is divided into several segments by the positional relationship of the geographic area of sub- ground map combining, and each section includes position Shape point in the geographic area of the electronic map covering to be shown；

For each section after division, the maximum spacing for the adjacent shapes point that this section is included is determined；

The size for comparing the maximum spacing of each section of adjacent shapes for being included point, by the maximum section of determination of maximum spacing intermediate value For candidate segment；

Section centered on the section that the shape point that the candidate segment medium spacing is equal to maximum spacing is formed；

Calculate the length of the text to be marked；

Judge whether the length of the candidate segment is greater than the length of the text to be marked；

If so, using the shape point at center section both ends as starting point, the shape point with the both ends of the candidate segment is Terminal；

For each starting point, since the starting point, it is located at the shape between the starting point and its adjacent terminal in the candidate segment In shape point, sequential search meets the shape point for setting tortuous condition, until the corresponding stopping shape point of the starting point is searched, it is described to stop Only shape point is not meet to set tortuous condition or the stopping shape point as the terminal；

Using the section of the corresponding two shape point compositions stopped between shape point of two starting points as target road section.

Preferably, described since the starting point, it is located at the shape between the starting point and its adjacent terminal in the candidate segment In point, sequential search meets the shape point for setting tortuous condition, until searching the corresponding stopping shape point of the starting point, comprising:

From starting point P₀Start, it is suitable in the shape point that the candidate segment is located between the starting point and its adjacent terminal Sequence selected shape point, if the shape point chosen is the terminal, the shape point of the selection is to stop shape point otherwise holding Row following steps:

It is elected that get is shape point P₁, then ∠ P is obtained₁P₀P’₀Angle value, if the angle value is greater than preset the One angle threshold, the then P₁For starting point P₀Corresponding stopping shape point；

When that read is shape point P_i, i initial value is 2, obtains ∠ P_iP_i-1P_i-2With ∠ P_iP₀P’₀Angle value, every choosing Take shape point an i=i+1, P '₀To be different from P₀Another starting point；

If ∠ P_iP_i-1P_i-2Greater than preset first angle threshold value or ∠ P_iP₀P’₀Angle value be greater than preset second Angle threshold, the then P_iFor starting point P₀Corresponding stopping shape point.

Preferably, in the target road section, the section that can mark the text to be marked of the road is obtained, comprising:

According to the length of text to be marked single in the text to be marked of the road, in the adjacent shape of the target road section At least one rectangle frame is generated between shape point and obtains its position, between the central point of the adjacent rectangle frame between adjacent shapes point Away from the length for being equal to single text to be marked；

According to the position of occupied rectangle frame and the position of the rectangle frame of generation, determine whether the rectangle frame generated is occupied With；

By it is continuous, be determined as unoccupied and number and be divided into a rectangle not less than the rectangle frame of text number to be marked Frame group；

If the rectangle frame group only has one, the section that the rectangle frame group occupies in the target road section is that can mark Infuse the section of the text to be marked of the road；

If the rectangle frame group obtains the section that the rectangle frame group occupies in the target road section there are two more than To the distance value in the center section, the corresponding section of lowest distance value is the road that can mark the text to be marked of the road Section.

A kind of Road letterings labeling position determining device, comprising:

Region decision unit, for judging electronic map and the geographic area for the electronic map covering having been displayed to be shown It is whether identical, a bar navigation route is illustrated on the electronic map having been displayed；

Area acquisition unit, for obtaining electronics to be shown when the region decision unit judges result is different The geographical coverage area of ground map combining；

Intersect judging unit, for judge the electronic map covering to be shown geographical coverage area and the navigation Whether the geographical coverage area of route covering intersects；

Labeling position determination unit, for it is described intersection judging unit judging result be intersection when, according to constitute institute The shape point set for stating the road of navigation routine determines the text to be marked of the road in the electronic map to be shown Labeling position.

Preferably, described device further include:

Information acquisition unit, for obtaining the map zoom levels of electronic map to be shown and the line width letter of the road Breath；

Unit is vacuated, for the line width information according to the map zoom levels and the road, to the road Shape point in shape point set is vacuated, and the shape point set for vacuating rear road is obtained.

Preferably, the unit that vacuates is according to the line width information of the map zoom levels and the road, to described Shape point in the shape point set of road is vacuated, and is obtained the process for the shape point set for vacuating rear road, is specifically included:

The map zoom levels are compared with the map zoom levels threshold value of setting, if the map zoom levels Greater than setting map level of zoom threshold value, then judge the distance whether be more than it is described vacuate jump point threshold value, protected if so, determining The shape point of the selection is stayed, if not, it is determined that vacuate the shape point of the selection；

Preferably, each shape point is provided with and vacuates label in the shape point set, and the unit that vacuates is according to The line width information of map zoom levels and the road vacuates the shape point set of the road, obtains the road The process for vacuating rear shape point set on road, further includes:

If indicating, this is vacuated labeled as invalid, judge the distance whether be more than it is described vacuate jump point threshold value, if so, Determine the shape point for retaining the selection, if not, it is determined that vacuate the shape point of the selection；

Preferably, the unit that vacuates obtains institute according to the line width information of the map zoom levels and the road The process for vacuating jump point threshold value for stating road, specifically includes:

Preferably, the labeling position determination unit is according to the shape point set of the road for constituting the navigation routine, really The process of labeling position of the text to be marked of the fixed road in the electronic map to be shown, specifically includes:

In the target road section, the section that can mark the text to be marked of the road is searched, as the road The labeling position of text to be marked.

Preferably, the labeling position determination unit is according to shape in the shape point set for the road for constituting the navigation routine The position of shape point, obtains one section of continuous target shape point, the target shape point constitute for mark the road wait mark The process of the target road section of explanatory notes word, specifically includes:

Calculate the length of the text to be marked；

Preferably, the labeling position determination unit is located at the starting point and its phase in the candidate segment since the starting point In shape point between adjacent terminal, sequential search meets the shape point for setting tortuous condition, until searching, the starting point is corresponding to stop The only process of shape point, specifically includes:

Preferably, the labeling position determination unit is in the target road section, obtain can mark the road wait mark The process in the section of explanatory notes word, specifically includes:

It can be seen from the above technical scheme that Road letterings labeling position provided by the embodiments of the present application determines scheme, Judge whether electronic map to be shown is identical as the geographic area for the electronic map covering having been displayed, the electronics having been displayed A bar navigation route is illustrated on map, if it is different, then obtaining the geographical coverage area of electronic map covering to be shown；Sentence Break the electronic map covering to be shown geographical coverage area and navigation routine covering geographical coverage area whether Intersection illustrates there is the road for constituting navigation routine in the geographical coverage area of electronic map covering to be shown if intersection Road, therefore according to the shape point set for the road for constituting the navigation routine, determine the text to be marked of the road described Labeling position in electronic map to be shown.The application quickly judges electronics to be shown by way of the intersection judgement of region Ground map combining geographical coverage area whether there is the road for constituting navigation routine, and in the case where determining intersection according to road Shape point set determine the labeling position of text to be marked, avoid the occurrence of and calculate Road letterings mark for not shown road Position is infused, so that the problem of causing computing resource waste, is greatly saved computing resource.

Detailed description of the invention

In order to illustrate the technical solutions in the embodiments of the present application or in the prior art more clearly, to embodiment or will show below There is attached drawing needed in technical description to be briefly described, it should be apparent that, the accompanying drawings in the following description is only this The embodiment of application for those of ordinary skill in the art without creative efforts, can also basis The attached drawing of offer obtains other attached drawings.

Fig. 1 determines method flow diagram for a kind of Road letterings labeling position disclosed in the embodiment of the present application；

Fig. 2 a-2b illustrates the geographical coverage area of electronic map covering to be shown and navigation routine covers geographic area Two kinds of intersection schematic diagrames of range；

Fig. 3 is that another kind Road letterings labeling position disclosed in the embodiment of the present application determines method flow diagram；

Fig. 4 is the method flow diagram that a kind of pair of shape point set disclosed in the embodiment of the present application is vacuated；

Fig. 5 is a kind of side for the labeling position that text to be marked is determined according to shape point set disclosed in the embodiment of the present application Method flow chart；

Fig. 6 is a kind of method flow diagram of determining target road section disclosed in the embodiment of the present application；

Fig. 7 is a kind of exemplary shape point division mode schematic diagram of road of the application；

Fig. 8 meets the method flow diagram for setting the shape point of tortuous condition for a kind of lookup disclosed in the embodiment of the present application；

Fig. 9 meets the shape point for setting tortuous condition for a kind of search in the candidate segment disclosed in the embodiment of the present application Schematic diagram；

Figure 10 can mark the method flow in text section for a kind of lookup in target road section disclosed in the embodiment of the present application Figure；

Figure 11 is that a kind of exemplary search in target road section of the application can mark the effect diagram in text section；

Figure 12 a is the display effect schematic diagram carried out after Road letterings mark according to the prior art；

Figure 12 b is the display effect schematic diagram carried out after Road letterings mark according to the application method；

Figure 13 is a kind of Road letterings labeling position determining device structural schematic diagram disclosed in the embodiment of the present application.

Specific embodiment

Below in conjunction with the attached drawing in the embodiment of the present application, technical solutions in the embodiments of the present application carries out clear, complete Site preparation description, it is clear that described embodiments are only a part of embodiments of the present application, instead of all the embodiments.It is based on Embodiment in the application, it is obtained by those of ordinary skill in the art without making creative efforts every other Embodiment shall fall in the protection scope of this application.

Referring to Fig. 1, Fig. 1 determines method flow diagram for a kind of Road letterings labeling position disclosed in the embodiment of the present application.

As shown in Figure 1, this method comprises:

Step S100, judge electronic map to be shown and the electronic map covering having been displayed geographic area whether phase Together, a bar navigation route is illustrated on the electronic map having been displayed, if not, thening follow the steps S110；

Specifically, the navigation routine shown on the electronic map that client has been displayed is, according to what is got from server The shape point set for constituting the road of navigation routine is drawn.

Client response user drag operation, scaling map zoom levels operation or it is other may relate to change shown The operation of the covered geographical coverage area of the electronic map shown needs again to render drawing (containing map and navigation routine) When, then judge whether electronic map to be shown is identical as the geographic area for the electronic map covering having been displayed.It is understood that It is, if the geographic area of covering is identical, then it represents that do not need to re-start the drafting of road mark, otherwise, expression needs weight The new drafting for carrying out road mark.

Step S110, the geographical coverage area of electronic map covering to be shown is obtained；

Specifically, the geographic area model of electronic map covering to be shown can be determined by invocation map engine interface It encloses, which is usually a rectangular area.

Step S120, judge geographical coverage area and the navigation routine covering of the electronic map covering to be shown Geographical coverage area whether intersect, if so, thening follow the steps S130；If it is not, then illustrating in electronic map to be shown There is no the road for constituting navigation routine, the drafting for re-starting road mark is not needed.

Wherein, the geographical coverage area of the navigation routine covering can be the road for enclosing and constituting the navigation routine Shape point set in all shape points geographic area range.

In this step, the geographic area of geographical coverage area and navigation routine covering to electronic map covering to be shown Range carries out intersection judgement.It is understood that illustrating to exist to constitute in electronic map to be shown to lead if the two intersects Otherwise the road of air route line illustrates that there is no the roads for constituting navigation routine in electronic map to be shown.

Referring to Fig. 2 a and Fig. 2 b, the geographical coverage area for illustrating electronic map covering to be shown is covered with navigation routine Two kinds of intersection schematic diagrames of lid geographical coverage area.

Wherein, the geographical coverage area of electronic map to be shown covering can be indicated with bounds1, navigation routine covering Geographical coverage area can be indicated with bounds2.

Step S130, according to the shape point set for the road for constituting the navigation routine, the to be marked of the road is determined Labeling position of the text in the electronic map to be shown.

Specifically, when judgement is intersected in the previous step, illustrate there is composition navigation routine in electronic map to be shown Road determine that the text to be marked of the road exists therefore according to the shape point set for the road for constituting the navigation routine Labeling position in the electronic map to be shown.Certainly, if judging in the previous step non-intersecting, illustrate to be shown Electronic map in there is no the roads for constituting navigation routine, therefore can be calculated with saving without the calculating of labeling position Resource.

Road letterings labeling position provided by the embodiments of the present application determines method, quick by way of the intersection judgement of region Judge that electronic map covering geographical coverage area to be shown intersects with the presence or absence of the road for constituting navigation routine, and determining In the case where the labeling position of text to be marked is determined according to the shape point set of road, avoid the occurrence of for not shown road Road calculates Road letterings labeling position, so that the problem of causing computing resource waste, is greatly saved computing resource.

Referring to Fig. 3, Fig. 3 is that another kind Road letterings labeling position disclosed in the embodiment of the present application determines method flow diagram. As shown in figure 3, this method comprises:

Step S200, judge electronic map to be shown and the electronic map covering having been displayed geographic area whether phase Together, a bar navigation route is illustrated on the electronic map having been displayed, if not, thening follow the steps S210；

Step S210, the geographical coverage area of electronic map covering to be shown is obtained；

Step S220, judge geographical coverage area and the navigation routine covering of the electronic map covering to be shown Geographical coverage area whether intersect, if so, thening follow the steps S230；

Specifically, step S100-S120 is corresponded in the process of step S200-S220 and above-described embodiment, is situated between in detail Continuing can refer to above, and details are not described herein again.

Step S230, the map zoom levels of electronic map to be shown and the line width information of the road are obtained；

Specifically, client can store pattern file, can specify that the line width information of road in pattern file.Certainly, Client can also obtain the line width information of road from server.

Step S240, according to the line width information of the map zoom levels and the road, to the shape of the road Shape point in point set is vacuated, and the shape point set for vacuating rear road is obtained；

Step S250, according to the shape point set for vacuating rear road for constituting the navigation routine, the road is determined Labeling position of the text to be marked in the electronic map to be shown.

The present embodiment is compared with previous embodiment, the present embodiment level of zoom and the line width information of road according to the map, The shape point set of road is vacuated, improves the efficiency for calculating labeling position to a certain extent, meanwhile, because vacuating Reduce some shape points, so that shape point spacing is increased, to improve to obtain the probability of labeling position.

Further, to above-mentioned S240, according to the line width information of the map zoom levels and the road, to the road Shape point in the shape point set on road is vacuated, and the shape point set for vacuating rear road is obtained, and following the application will combine Specific embodiment describes in detail.

Before introduction vacuates embodiment, the shape point set of road is described further first.Client can be from Server obtains the shape point set of road, and each shape point, which is also provided with, in shape point set vacuates label, vacuates mark The different values of note indicate that this is vacuated and mark whether effectively.If it is effective to vacuate label, then it represents that corresponding shape point is in map Level of zoom can be vacuated directly when being less than setting map level of zoom threshold value.Practical feelings of the server previously according to road Condition, when map zoom levels are less than setting map level of zoom threshold value by unessential shape point a part of in shape point set The label that vacuates be set as effectively, so that client can determine whether to take out respective shapes point according to the label It is dilute.Wherein, setting map level of zoom threshold value can according to the actual situation depending on, such as 10 or other numerical value.It lifts for example, vacuating When labeled as 0, expression vacuates label effectively, and correspondingly-shaped point can be vacuated directly when map zoom levels are less than 10 grades Fall.

Based on above-mentioned introduction, the embodiment of the present application discloses the method stream that the shape point set of a kind of pair of road is vacuated Cheng Tu, as shown in figure 4, this method comprises:

Step S300, level of zoom and the line width information of road according to the map, obtain the road vacuates jump point threshold Value；

Specifically, the application can be pre-designed the corresponding jump point threshold value filterLen that vacuates of map zoom levels and calculate Formula, alternatively, the combination of shape point number is corresponding in map zoom levels and shape point set vacuates jump point threshold value FilterLen calculation formula.Wherein, vacuate jump point threshold value filterLen calculation formula be vacuate jump point threshold value filterLen with The numerical relation of the line width of road.

Based on this, in the available and map level or the map level and the shape point set of the road The combination of shape point number is corresponding to vacuate formula, according to the line width information for vacuating formula and the road, calculates the pumping of road Dilute jump point threshold value filterLen.That is, bring the line width of road into acquisition vacuate in jump point threshold value filterLen calculation formula, And then it obtains vacuating jump point threshold value filterLen.

It is illustrated below:

Map zoom levels are divided into four kinds of situations by the embodiment of the present application, and four kinds of situations, which respectively correspond, different vacuates jump Point threshold value filterLen calculation formula, as follows:

(1), nMaplevel >=17, filterLen=0 indicates not having to vacuate；

(2), 15,16 grades of nMapLevel, filterLen=k1*nLineWidth；

(3), shape point number in nMapLevel≤9 and shape point set >=100, filterLen=k2* nLineWidth；

(4), remaining situation filterLen=k3*nLineWidth.

Above-mentioned nMaplevel indicates map zoom levels, and filterLen expression vacuates jump point threshold value, nLineWidth table Show the line width of road, k1-k3 indicates coefficient value.

Step S310, a shape point successively is chosen from the shape point set of the road, calculates the shape point of the selection The distance nTempLen between next adjacent shapes point；

Specifically, a shape point P is successively chosen from the shape point set of road_i, calculate shape point P_iWith next adjacent shape Shape point P_i+1Between distance nTempLen.

Step S320, determine whether the map zoom levels are greater than the map zoom levels threshold value of setting；If so, executing Step S330, if it is not, executing step S340；

Step S330, according to the size relation of the nTempLen and filterLen, it is determined whether take out the shape point It is dilute fall；

Specifically, if map zoom levels are greater than setting map level of zoom threshold value, determining whether to take out shape point i It is dilute fall when, it is only necessary to consider the size relation of the nTempLen and filterLen.

In a kind of optional embodiment, it can be determined that whether nTempLen protects more than filterLen if so, determining Stay the shape point P of selection_i, if not, it is determined that by the shape point P of selection_iIt vacuates.

Wherein, the shape point of reservation constitutes the shape point set for vacuating rear road.

Step S340, according to the value for vacuating label of the shape point, the size of the nTempLen and filterLen Relationship, it is determined whether vacuate the shape point.

Specifically, if map zoom levels are no more than setting map level of zoom threshold value, determine whether will to choose Shape point P_iWhen vacuating, need to comprehensively consider shape point P_iThe value for vacuating label and the nTempLen with The size relation of filterLen.

In a kind of optional embodiment, if map zoom levels are no more than setting map level of zoom threshold value, judge The shape point P of selection_iThe value for vacuating label indicate whether that this is vacuated labeled as effective；If indicating that this is vacuated to be labeled as having Effect, then by the shape point P of selection_iIt vacuates；If indicating, this is vacuated labeled as invalid, judge nTempLen whether be more than FilterLen, if so, determining the shape point P for retaining and choosing_i, if not, it is determined that by the shape point P of selection_iIt vacuates.

Further, in above-mentioned steps S130, according to the shape point set for the road for constituting the navigation routine, institute is determined Labeling position of the text to be marked of road in the electronic map to be shown is stated, following the application will be carried out in conjunction with Fig. 5 It introduces, which may include:

Step S400, according to the position of shape point in the shape point set for the road for constituting the navigation routine, one is obtained The continuous target shape point of section, the target shape point constitute the target road section for marking the text to be marked of the road, The length of the target road section meets not less than the length and tortuous of the text to be marked sets tortuous condition；

Wherein, the length of text to be marked can be calculated according to word attribute, general, the length of text to be marked Degree is equal to the width in region shared by single text to be marked multiplied by text number to be marked.

Wherein, the tortuous of target road section also needs to meet the tortuous condition of setting, namely needs to guarantee that target road section is most It measures flat, and avoids the occurrence of the excessive situation of tortuous, the text of mark is caused to be not easy to user's viewing.

It should be noted that in each shape point that the tortuous of target road section can be included by target road section, phase Angle between the sub- section of adjacent shape point composition determines.

Further, if being vacuated before step S400 to the shape point in the shape point set of road, this The shape point set of road in step is to vacuate the shape point set of rear road.

Step S410, in the target road section, the section that can mark the text to be marked of the road is obtained, as institute State the labeling position of the text to be marked of road.

After finding target road section, the section that can mark the text to be marked of the road is further therefrom searched, It specifically can be not by other text occupy-places, and length is not less than the section of the length of the text to be marked of road.

It is understood that the number in the section finally found and being not fixed, it may be possible to zero, it is also possible to be one It is a or multiple.

If the number in the section found is zero, then it represents that the section of the condition of satisfaction is not found, it can not be to be marked Text is labeled, and is exited, i.e., is not labeled to the text to be marked.

If the number in the section found is one or more, a section can be determined from the section found, The labeling position of text to be marked as the road.

In the method for the labeling position of the text to be marked of the determination of the present embodiment introduction road, first in shape point The target road section that the condition that meets is searched in set, further obtains the text to be marked that can mark the road from target road section Section, therefrom determine the labeling position of the text to be marked of the road.According to the application method, final lookup ensure that The labeling position arrived is in relatively flat section, ensure that the text checked after mark that user can be convenient.

In another embodiment of the application, to above-mentioned steps S400, according to the road for constituting the navigation routine The position of shape point in shape point set, obtains one section of continuous target shape point, and the target shape point is constituted for marking The process of the target road section of the text to be marked of the road is introduced, as shown in connection with fig. 6, this method comprises:

Step S500, according to the position of shape point in the shape point set for the road for constituting the navigation routine and it is described to The positional relationship of the geographic area of the electronic map covering of display, is divided into several segments for the shape point of the road；

Wherein it is possible to guarantee that each section after dividing may include positioned at described to aobvious according to certain division rule Shape point in the geographic area for the electronic map covering shown.

In a kind of optional embodiment, the shape point in the shape point set of road can be traversed, therefrom determines to face Boundary's shape point, critical shape point is located at except the geographic area that electronic map to be shown covers, and critical shape point is previous Adjacent shapes point or latter adjacent shapes point are located within the geographic area that electronic map to be shown covers.By critical shape point And the shape point being located within the geographic area that electronic map to be shown covers between critical shape point is divided into one point In section.

It is illustrated in conjunction with shape point partition process of the Fig. 7 to road:

Exemplary route includes P0-Pn shape point in Fig. 7, and electronic map covering geographic area to be shown is S1.From Fig. 7 As can be seen that P1, P5, P9, P11, P14 are therefore shape point is divided into three sections, be respectively as follows: by critical shape point

[P1…P5]、[P5…P9]、[P11…P14]。

Step S510, for each section after division, the maximum spacing for the adjacent shapes point that this section is included is determined；

Specifically, each section after division includes several shape points.Spacing between determining wherein adjacent shapes point, and from Maximum spacing is determined in each spacing.

Step S520, the size of the maximum spacing of each section of the comparison adjacent shapes point for being included, most by maximum spacing intermediate value Big section is determined as candidate segment；

Specifically, a maximum spacing has been determined for each section in previous step.In this step, more each maximum Maximum spacing intermediate value is determined as candidate segment for maximum section by the size of spacing.

Specifically, it is still illustrated by taking above-mentioned Fig. 7 as an example:

As seen in Figure 7, maximum spacing is [P1-P2] segment length L1 in [P1 ... P5] section；It is maximum in [P5 ... P9] section Spacing is [P6-P7] segment length L2；Maximum spacing is [P12-P13] segment length L3 in [P11 ... P14] section.Assuming that L3 > L1 > L2, then may be used To determine candidate segment for [P12-P13].

In this step from each section after division, determine that maximum section of intermediate value of spacing of maximum is candidate segment, it is subsequent can be from Target road section is intercepted in the candidate segment.Since the candidate segment includes the maximum adjacent shapes point of spacing, from the candidate segment Be calculated hold the probability of the position of text to be marked enough can be bigger, improve the probability that labeling position is calculated, And guarantee the labeling position being calculated close to flat section.

Step S530, road centered on the section for forming the shape point that the candidate segment medium spacing is equal to maximum spacing Section；

Step S540, the length of the text to be marked is calculated；

Step S550, judge whether the length of the candidate segment is greater than the length of the text to be marked；If it is not, then moving back Out；If so, executing step S560；

Specifically, if the length of candidate segment is not more than the length of text to be marked, then it represents that labeling position can not be found, End can be exited.

Step S560, using the shape point at center section both ends as starting point, with the shape point at the both ends of the candidate segment For terminal；

Step S570, it is located at the starting point and its adjacent terminal in the candidate segment since the starting point for each starting point Between shape point in, sequential search meets the shape point for setting tortuous condition, until searching the corresponding stopping shape of the starting point Point；

Wherein, the stopping shape point is not meet to set tortuous condition or the stopping shape point as the terminal.

Step S580, using the section of the corresponding two shape point compositions stopped between shape point of two starting points as target Section.

In the disclosed method for searching target road section of the present embodiment, by the shape point of road according to electronic map to be shown Overlay area is divided into several segments, and every section includes the shape point being located in electronic map overlay area to be shown, from division In each section afterwards, the candidate segment comprising the maximum adjacent shapes point of spacing is determined, it is subsequent to intercept target road section from the candidate segment. Since the candidate segment includes the maximum adjacent shapes point of spacing, it is calculated from the candidate segment and holds text to be marked enough The probability of the position of word can be bigger, improves the probability that labeling position is calculated, and guarantee the labeling position being calculated Close to flat section.

In another embodiment of the application, to above-mentioned steps S570, for each starting point, since the starting point, The candidate segment is located in the shape point between the starting point and its adjacent terminal, and sequential search meets the shape for setting tortuous condition Point is introduced until searching the corresponding process for stopping shape point of the starting point, as shown in connection with fig. 8, this method comprises:

Step S600, from starting point P₀Start, is located at the shape between the starting point and its adjacent terminal in the candidate segment In shape point, sequence selected shape point；

Specifically, the shape point at center section both ends is respectively starting point, and one of starting point is expressed as P₀, another starting point It is expressed as P '₀。

Step S610, judge whether the shape point chosen is the terminal, if so, thening follow the steps S620, otherwise, execute Step S630；

Step S620, determine that the shape point chosen is starting point P₀Corresponding stopping shape point；

It is step S630, elected that get is shape point P₁, then ∠ P is obtained₁P₀P’₀Angle value；

If step S640, the described angle value is greater than preset first angle threshold value, the P₁For starting point P₀It is corresponding to stop Only shape point；

Step S650, when that read is shape point P_i, i initial value is 2, obtains ∠ P_iP_i-1P_i-2With ∠ P_iP₀P’₀Angle Angle value, one shape point i=i+1 of every selection；

If step S660, ∠ P_iP_i-1P_i-2Greater than preset first angle threshold value or ∠ P_iP₀P’₀Angle value be greater than it is pre- If second angle threshold value, then the P_iFor starting point P₀Corresponding stopping shape point.

Wherein, first angle threshold value and second angle threshold value can not be limited with sets itself, the two size relation.

In order to make it easy to understand, existing for example:

Referring to Fig. 9, Fig. 9 is searched in the candidate segment for one kind disclosed in the embodiment of the present application meets the tortuous condition of setting Shape point schematic diagram.

In Fig. 9, P1-Pn is the shape point that candidate road section includes, and [Pn4-Pn5] is center section.

It is as follows for from Pn4 to the process of the side P1 expanding query:

1, the vector by Pn3 to Pn4, the angle ∠ Pn3Pn4Pn5 with the vector by Pn4 to Pn5 are calculated, and determines the folder Angle is less than a1.Continuation detects forward.

2, the vector by Pn2 to Pn3, the angle ∠ Pn2Pn3Pn4 with the vector by Pn3 to Pn4 are calculated, and determines the folder Angle ∠ Pn2Pn3Pn4 is less than a1；

3, the vector by Pn2 to Pn4, the angle ∠ Pn2Pn4Pn5 with the vector by Pn4 to Pn5 are calculated, and determines the folder Angle ∠ Pn2Pn4Pn5 is less than a2.Continuation detects forward.

4, the vector by Pn1 to Pn2, the angle ∠ Pn1Pn2Pn3 with the vector by Pn2 to Pn3 are calculated, and determines the folder Angle ∠ Pn1Pn2Pn3 is greater than a1, it is thus determined that Pn1 is to stop shape point.

It is as follows for from Pn5 to the process of the side Pn expanding query:

1, the vector by Pn6 to Pn5, the angle ∠ Pn6Pn5Pn4 with the vector by Pn5 to Pn4 are calculated, and determines the folder Angle ∠ Pn6Pn5Pn4 is less than a1.Continuation detects forward.

2, the vector by Pn7 to Pn6, the angle ∠ Pn7Pn6Pn5 with the vector by Pn6 to Pn5 are calculated, and determines the folder Angle ∠ Pn7Pn6Pn5 is less than a1；

3, the vector by Pn7 to Pn5, the angle ∠ Pn7Pn5Pn4 with the vector by Pn5 to Pn4 are calculated, and determines the folder Angle ∠ Pn7Pn5Pn4 is greater than a2, it is thus determined that Pn7 is to stop shape point.

Finally, the section of Pn1 to the shape point composition between Pn7 is determined as target road section, wherein target road section is not wrapped Include Pn1 and Pn7.

In another embodiment of the application, to above-mentioned steps S410, in the target road section, acquisition can mark institute The process in the section for stating the text to be marked of road, the labeling position of the text to be marked as the road is introduced, knot It closes shown in Figure 10, this method comprises:

Step S700, according to the length of text to be marked single in the text to be marked of the road, on the target road At least one rectangle frame is generated between the adjacent shapes point of section and obtains its position；

Wherein, the spacing of the central point of the adjacent rectangle frame between adjacent shapes point is equal to the length of single text to be marked Degree.

Step S710, according to the position of occupied rectangle frame and the position of the rectangle frame of generation, the rectangle frame generated is determined It is whether occupied；

Specifically, the position of occupied rectangle frame can be stored in advance in the application.It in turn, can be according to quilt in this step The position of the position of rectangle frame and the rectangle frame of generation is occupied, determines whether the rectangle frame generated is occupied.

Step S720, by it is continuous, be determined as rectangle frame point of the unoccupied and number not less than text number to be marked Enter a rectangle frame group；

If step S730, the described rectangle frame group only has one, what the rectangle frame group occupied in the target road section Section is the section that can mark the text to be marked of the road；

If step S740, the described rectangle frame group obtains the rectangle frame group in the target road section there are two more than To the distance value in the center section, the corresponding section of lowest distance value is that can mark the to be marked of the road in the section of occupancy The section of text.

Optionally, the embodiment of the present application describes a kind of road for obtaining the rectangle frame group and occupying in the target road section Section arrives the optional embodiment of the distance value in the center section.For the ease of statement, rectangle frame group is defined on the target road The section occupied in section is occupy-place section.Then distance value acquisition modes may include:

Calculate the central point of occupy-place section and the distance between the central point in center section, the distance value as the two.

In addition to this it is possible to calculate the starting point of occupy-place section at a distance from the starting point in center section, or calculate occupy-place Distance value of the terminating point of section at a distance from the terminating point in center section, as the two.

It is the text to be marked that can mark the road that the corresponding section of lowest distance value can be chosen in the present embodiment Section.Since center section is straight line, chooses and it apart from nearest section is used as labeling position, so that mark is literary Word is more favorable for user's viewing close to flat section.

In conjunction with the exemplary scene of Figure 11, the process of above-mentioned Figure 10 corresponding embodiment is illustrated.

Shape point P1-P6 forms target road section in Figure 11, wherein P3-P4 organization center section.Text number to be marked is 4。

Rectangle frame is generated between two neighboring shape point in target road section, the spacing of the central point of adjacent rectangle frame is equal to The length of single text to be marked.

In Figure 11, the unfilled rectangle frame of white represents unappropriated rectangle frame, and the rectangle frame of oblique line filling represents Occupied rectangle frame.

Rectangle frame by continuous, unoccupied and number not less than text number to be marked is divided into a rectangle frame group In.Rectangle frame group seg1 and rectangle frame group seg2 it follows that available two rectangle frame groups, i.e. in Figure 11.

Since there are two rectangle frame groups, then calculates separately two rectangle frame groups and occupy section to center in target road section The distance value in section, and select the corresponding section of lowest distance value, i.e. the corresponding section seg1 as can mark road wait mark The section of explanatory notes word.

It is provided in this embodiment, the mode of labeling position is searched in the target road section, is looked into according to rectangle frame mode Available section is looked for, as the labeling position of text to be marked, lookup result is more accurate.

Wherein, step S700 generates the process of rectangle frame, can implement as follows:

Defined parameters first:

The half fHalfFontSize of the width of single text to be marked；

The included shape point set of target road section [P1P2 ... PN]；

Variable fTmpOffSet records the cumulative distance of rectangle frame central point to be detected from previous nearest shape point, as Whether the line segment of adjacent two shape points composition detects the label finished, and fTmpOffSet initial length is fHalfFontSize；

The variable nRectCount of statistics rectangle frame number is initially 0；Record can place the total number of rectangle frame NSumCount=target road section length/single text occupy-place length.

Implementation process is as follows:

Step 1: sequence takes a shape point from the shape point set [P1P2 ... PN-1], calculate the shape point with it is next The length of a shape point line formed section is fListRoadLen, and calculates line segment direction unit vector, is used for subsequent calculating；

Step 2: judging whether fTmpOffSet is less than or equal to fListRoadLen, if it is, step 3 is executed, it is no Then follow the steps four；

Step 3: the line segment starting point obtained based on step 1, line taking segment endpoint direction length are the position of fTmpOffSet, As rectangle frame center, a rectangle frame is generated, the width of a height of text of the width of the rectangle frame of generation is high, executes step 5；

Step 4: taking fTmpOffset=fTmpOffset-fListRoadLen, jumps out circulation, executes step 1；

Step 5: the position of the rectangle frame of generation is saved；

Step 6: enabling nRectCount+1, and judges whether nRectCount has exceeded the maximum number that can be placed NSumCount if it is indicates that target road section all detects and goes over, terminates entire detection, EP (end of program).Otherwise step is executed Rapid seven；

Step 7: judge whether fTmpOffset+fHalfFontSize*2 is greater than fListRoadLen, it is clear that if big In, then it represents that the central point of next rectangle frame needs to continue to detect next line segment, at this moment needs to examine not on current line segment Consider the remaining surplus part of current line segment and resets fTmpOffset, fTmpOffset=fHalfFontSize*2+ FTmpOffset-fListRoadLen, and then execute step 1 and continue to detect, if fTmpOffset+fHalfFontSize*2 is not Greater than fListRoadLen, then it represents that the central point of next rectangle frame continues to execute step 8 also on current line segment；

Step 8: resetting fTmpOffset, fTmpOffset=fTmpOffset+fHalfFontSize*2, i.e., cumulative one A word length executes step 2.

Further, above-mentioned steps S720 determines the process of rectangle frame group, can implement as follows:

Defined parameters first:

For storing the label array bFlagArray of the whether occupied state of each rectangle frame generated, size is equal to The rectangle frame number nVexNum of generation；The number nCalCharSize of text to be marked；Continuous unoccupied rectangle is detected Frame number nCount, is initially 0.

Implementation process is as follows:

Step 1: sequentially taking out the occupied state of rectangle frame from bFlagArray, whether judges the occupied state taken out It indicates that corresponding rectangle frame is unoccupied, if it is step 2 is executed, otherwise executes step 3；

Step 2: enabling nCount+1, and the rectangle frame currently taken out is available rectangle frame, judges that the rectangle frame currently taken out is The no starting point for available Continuous Rectangular frame, will if it is write down the position of starting point, otherwise not need.Continue to execute step 1；

Step 3: when front frame is occupied rectangle frame, judge the continuous unoccupied rectangle frame number that front records It is whether enough, that is, judge whether to meet nCount >=nCalCharSize, if not, label does not find suitable position, open again Begin to detect, execute step 1, if so, executing step 4；

Step 4: the position of record nearest unappropriated rectangle frame before front frame, as final position, by The corresponding rectangle frame in point position to the corresponding rectangle frame of final position form one it is continuous, be determined as unoccupied and number not Less than the rectangle frame group of text number to be marked.

Finally after looping through the occupied state of each rectangle frame in bFlagArray, several rectangle frames are obtained Group.

Finally, now leading to prove that Road letterings labeling position provided by the embodiments of the present application determines the validity of method Figure 12 a and 12b is crossed to be illustrated:

The programme path to one from Beijing to Tianjin is now needed to carry out Road letterings mark.After being marked according to the prior art Effect as figure 12 a shows, according to the application method mark after effect as shown in Figure 12b.

Further, the application carries out segmentation division to the shape point of road, determines to include the maximum adjacent shapes point of spacing Candidate segment, therefore be calculated from the candidate segment hold the probability of the position of text to be marked enough can be bigger, improve The probability of labeling position is calculated, and guarantees the labeling position being calculated close to flat section.

Further, the application searches the position not occupied by other texts using rectangle frame mode, prevents from finding Labeling position be labeled with other texts, lead to the problem of text gland.

Comparison diagram 12a and Figure 12 b, which can be seen that, can not be calculated label character position according to the prior art, lead to nothing Faxian shows that Road letterings mark, and can find labeling position according to application scheme, and labeling position is located on flat section, And not with other text glands.

It is understood that the application is suitable for the embodiment that the shape point set of road is that process object describes Road vacuates rear shape point set, and particular content refers to related content, and the application is no longer described in detail.

Road letterings labeling position determining device provided by the embodiments of the present application is described below, road described below Road label character position determining means determine that method can correspond to each other reference with above-described Road letterings labeling position.

Referring to Figure 13, Figure 13 is a kind of Road letterings labeling position determining device structural representation disclosed in the embodiment of the present application Figure.

As shown in figure 13, which includes:

Region decision unit 11, for judging electronic map and the geographic region for the electronic map covering having been displayed to be shown Whether domain is identical, and a bar navigation route is illustrated on the electronic map having been displayed；

Area acquisition unit 12, for obtaining electricity to be shown when the region decision unit judges result is different The geographical coverage area of sub- ground map combining；

Intersect judging unit 13, for judging the geographical coverage area of the electronic map covering to be shown and described leading Whether the geographical coverage area of air route line covering intersects；

Labeling position determination unit 14, for it is described intersection judging unit judging result be intersection when, according to composition The shape point set of the road of the navigation routine determines the text to be marked of the road in the electronic map to be shown In labeling position.

Road letterings labeling position determining device provided by the embodiments of the present application, it is quick by way of the intersection judgement of region Judge that electronic map covering geographical coverage area to be shown intersects with the presence or absence of the road for constituting navigation routine, and determining In the case where the labeling position of text to be marked is determined according to the shape point set of road, avoid the occurrence of for not shown road Road calculates Road letterings labeling position, so that the problem of causing computing resource waste, is greatly saved computing resource.

Optionally, the device of the application can also include:

Optionally, the unit that vacuates is according to the line width information of the map zoom levels and the road, to described Shape point in the shape point set of road is vacuated, and the process for the shape point set for vacuating rear road is obtained, specifically can be with Include:

Optionally, each shape point is provided with and vacuates label in the shape point set, and the unit that vacuates is according to The line width information of map zoom levels and the road vacuates the shape point set of the road, after being vacuated The process of the shape point set of road can also include:

Optionally, for the unit that vacuates according to the line width information of the map zoom levels and road, calculating vacuates jump The process of point threshold value, can specifically include:

Wherein, it vacuates jump point threshold calculations formula to define under corresponding map zoom levels, vacuates jump point threshold value and road The numerical relation of the line width on road.

Optionally, the labeling position determination unit is according to the shape point set of the road for constituting the navigation routine, really The process of labeling position of the text to be marked of the fixed road in the electronic map to be shown, can specifically include:

Optionally, the labeling position determination unit is according to shape in the shape point set for the road for constituting the navigation routine The position of shape point, obtains one section of continuous target shape point, the target shape point constitute for mark the road wait mark The process of the target road section of explanatory notes word, can specifically include:

Calculate the length of the text to be marked；

Optionally, the labeling position determination unit is located at the starting point and its phase in the candidate segment since the starting point In shape point between adjacent terminal, sequential search meets the shape point for setting tortuous condition, until searching, the starting point is corresponding to stop The only process of shape point, can specifically include:

Optionally, the labeling position determination unit is in the target road section, obtain can mark the road wait mark The section of explanatory notes word, the labeling position of the text to be marked as road ground process, can specifically include:

Finally, it is to be noted that, herein, relational terms such as first and second and the like be used merely to by One entity or operation are distinguished with another entity or operation, without necessarily requiring or implying these entities or operation Between there are any actual relationship or orders.Moreover, the terms "include", "comprise" or its any other variant meaning Covering non-exclusive inclusion, so that the process, method, article or equipment for including a series of elements not only includes that A little elements, but also including other elements that are not explicitly listed, or further include for this process, method, article or The intrinsic element of equipment.In the absence of more restrictions, the element limited by sentence "including a ...", is not arranged Except there is also other identical elements in the process, method, article or apparatus that includes the element.

Each embodiment in this specification is described in a progressive manner, the highlights of each of the examples are with other The difference of embodiment, the same or similar parts in each embodiment may refer to each other.

The foregoing description of the disclosed embodiments makes professional and technical personnel in the field can be realized or use the application. Various modifications to these embodiments will be readily apparent to those skilled in the art, as defined herein General Principle can be realized in other embodiments without departing from the spirit or scope of the application.Therefore, the application It is not intended to be limited to the embodiments shown herein, and is to fit to and the principles and novel features disclosed herein phase one The widest scope of cause.

Claims

1. a kind of Road letterings labeling position determines method characterized by comprising

Judge whether electronic map to be shown is identical as the geographic area for the electronic map covering having been displayed, it is described to have been displayed A bar navigation route is illustrated on electronic map, if it is different, then obtaining the geographic area model of electronic map covering to be shown It encloses；

Judge the geographical coverage area of the electronic map covering to be shown and the geographic area model of navigation routine covering Enclose and whether intersect, if intersection, according to the shape point set for the road for constituting the navigation routine, determine the road to Mark labeling position of the text in the electronic map to be shown.

2. the method according to claim 1, wherein the method further includes:

According to the line width information of the map zoom levels and the road, to the shape in the shape point set of the road Point is vacuated, and the shape point set for vacuating rear road is obtained.

3. according to the method described in claim 2, it is characterized in that, described according to the map zoom levels and the road Line width information, the shape point in the shape point set of the road is vacuated, the shape point set for vacuating rear road is obtained It closes, comprising:

Successively choose a shape point from the shape point set of the road, calculate the selection shape point and next adjacent shapes The distance of point；

The map zoom levels are compared with the map zoom levels threshold value of setting, if the map zoom levels are greater than Setting map level of zoom threshold value, then judge the distance whether be more than it is described vacuate jump point threshold value, if so, retaining the choosing The shape point taken, if it is not, then the shape point by the selection vacuates；

4. according to the method described in claim 3, it is characterized in that, each shape point is provided with and vacuates in the shape point set Label, this method further include:

If the map zoom levels are no more than the setting map level of zoom threshold value, the shape point of the selection is judged The value for vacuating label indicates whether that this is vacuated labeled as effective；

If indicating, this is vacuated labeled as invalid, judge the distance whether be more than it is described vacuate jump point threshold value, if so, retaining The shape point of the selection, if it is not, then the shape point by the selection vacuates；

5. according to the method described in claim 3, it is characterized in that, described according to the map zoom levels and the road Line width information, obtain the road vacuates jump point threshold value, comprising:

6. method according to claim 1-5, which is characterized in that described according to the road for constituting the navigation routine The shape point set on road determines labeling position of the text to be marked of the road in the electronic map to be shown, packet It includes:

According to the position of shape point in the shape point set for the road for constituting the navigation routine, one section of continuous target shape is obtained Shape point, the target shape point constitute the target road section for marking the text to be marked of the road, the target road section Length meets not less than the length and tortuous of the text to be marked sets tortuous condition；

In the target road section, the section that can mark the text to be marked of the road is obtained, as the road wait mark The labeling position of explanatory notes word.

7. according to the method described in claim 6, it is characterized in that, the shape according to the road for constituting the navigation routine The position of shape point in point set, obtains one section of continuous target shape point, and the target shape point constitutes described for marking The target road section of the text to be marked of road, comprising:

According to the position of shape point in the shape point set for the road for constituting the navigation routine and it is described it is to be shown electronically The shape point of the road is divided into several segments by the positional relationship of the geographic area of map combining, and each section comprising being located at institute State the shape point in the geographic area of electronic map covering to be shown；

Maximum spacing intermediate value is determined as waiting for maximum section by the size for comparing the maximum spacing of each section of adjacent shapes for being included point Selections；

Calculate the length of the text to be marked；

If so, using the shape point at center section both ends as starting point, using the shape point at the both ends of the candidate segment as terminal；

For each starting point, since the starting point, it is located at the shape point between the starting point and its adjacent terminal in the candidate segment In, sequential search meets the shape point for setting tortuous condition, until searching the corresponding stopping shape point of the starting point, the stopping shape Shape point is not meet to set tortuous condition or the stopping shape point as the terminal；

8. being located in the candidate segment should the method according to the description of claim 7 is characterized in that described since the starting point In shape point between starting point and its adjacent terminal, sequential search meets the shape point for setting tortuous condition, until searching this The corresponding stopping shape point of point, comprising:

From starting point P₀Start, in the shape point that the candidate segment is located between the starting point and its adjacent terminal, sequence is chosen Shape point, if the shape point chosen is the terminal, the shape point of the selection is to stop shape point, otherwise, is executed following Step:

It is elected that get is shape point P₁, then ∠ P is obtained₁P₀P’₀Angle value, if the angle value be greater than preset first angle Threshold value, the then P₁For starting point P₀Corresponding stopping shape point；

When that read is shape point P_i, i initial value is 2, obtains ∠ P_iP_i-1P_i-2With ∠ P_iP₀P’₀Angle value, it is every choose one A shape point i=i+1, P '₀To be different from P₀Another starting point；

If ∠ P_iP_i-1P_i-2Greater than preset first angle threshold value or ∠ P_iP₀P’₀Angle value be greater than preset second angle threshold It is worth, then the P_iFor starting point P₀Corresponding stopping shape point.

9. the method according to the description of claim 7 is characterized in that acquisition can mark the road in the target road section Text to be marked section, comprising:

According to the length of text to be marked single in the text to be marked of the road, in the adjacent shapes point of the target road section Between generate at least one rectangle frame and obtain its position, the spacing etc. of the central point of the adjacent rectangle frame between adjacent shapes point In the length of single text to be marked；

According to the position of occupied rectangle frame and the position of the rectangle frame of generation, determine whether the rectangle frame generated is occupied；

By it is continuous, be determined as unoccupied and number and be divided into a rectangle frame not less than the rectangle frame of text number to be marked Group；

If the rectangle frame group only has one, the section that the rectangle frame group occupies in the target road section is can mark institute State the section of the text to be marked of road；

If the rectangle frame group there are two more than, obtains section that the rectangle frame group occupies in the target road section to institute The distance value in center section is stated, the corresponding section of lowest distance value is the section that can mark the text to be marked of the road.

10. a kind of Road letterings labeling position determining device characterized by comprising

Region decision unit, for judge electronic map to be shown and the electronic map covering having been displayed geographic area whether It is identical, a bar navigation route is illustrated on the electronic map having been displayed；

Area acquisition unit, for obtaining electronic map to be shown when the region decision unit judges result is different The geographical coverage area of covering；

Intersect judging unit, for judging the geographical coverage area and the navigation routine of the electronic map covering to be shown Whether the geographical coverage area of covering intersects；

Labeling position determination unit, for being led according to composition when the judging result of the intersection judging unit is intersection The shape point set of the road of air route line determines mark of the text to be marked of the road in the electronic map to be shown Infuse position.

11. device according to claim 10, which is characterized in that described device further include:

Information acquisition unit, for obtaining the map zoom levels of electronic map to be shown and the line width information of the road；

Unit is vacuated, for the line width information according to the map zoom levels and the road, to the shape of the road Shape point in point set is vacuated, and the shape point set for vacuating rear road is obtained.

12. device according to claim 11, which is characterized in that it is described vacuate unit according to the map zoom levels with And the line width information of the road, the shape point in the shape point set of the road is vacuated, obtains vacuating rear road Shape point set process, specifically include:

The map zoom levels are compared with the map zoom levels threshold value of setting, if the map zoom levels are greater than Setting map level of zoom threshold value, then judge the distance whether be more than it is described vacuate jump point threshold value, retain institute if so, determining The shape point of selection is stated, if not, it is determined that vacuate the shape point of the selection；

13. device according to claim 12, which is characterized in that each shape point is provided with pumping in the shape point set Dilute label, the unit that vacuates is according to the line width information of the map zoom levels and the road, to the shape of the road Shape point set is vacuated, and the process for vacuating rear shape point set of the road is obtained, further includes:

If indicating, this is vacuated labeled as invalid, judge the distance whether be more than it is described vacuate jump point threshold value, if so, determining Retain the shape point of the selection, if not, it is determined that vacuate the shape point of the selection；

14. device according to claim 12, which is characterized in that it is described vacuate unit according to the map zoom levels with And the line width information of the road, the process for vacuating jump point threshold value of the road is obtained, is specifically included:

15. the described in any item devices of 0-14 according to claim 1, which is characterized in that the labeling position determination unit according to The shape point set for constituting the road of the navigation routine determines the text to be marked of the road in the electronics to be shown The process of labeling position in map, specifically includes:

In the target road section, the section that can mark the text to be marked of the road is searched, as the road wait mark The labeling position of explanatory notes word.

16. device according to claim 15, which is characterized in that the labeling position determination unit is led according to composition The position of shape point in the shape point set of the road of air route line obtains one section of continuous target shape point, the target shape Point constitutes the process for marking the target road section of the text to be marked of the road, specifically includes:

Calculate the length of the text to be marked；

17. device according to claim 16, which is characterized in that the labeling position determination unit since the starting point, In the shape point that the candidate segment is located between the starting point and its adjacent terminal, sequential search meets the shape for setting tortuous condition Shape point specifically includes until searching the corresponding process for stopping shape point of the starting point:

18. device according to claim 16, which is characterized in that the labeling position determination unit is in the target road section In, the process that can mark the section of text to be marked of the road is obtained, is specifically included: