The application is on 06 03rd, 2013 submission Patent Office of the People's Republic of China, application No. is 201310216574.8, denominations of inventionFor the divisional application of the Chinese patent application of " method and apparatus in positioning cards region ".
Summary of the invention
Therefore, the skill for being designed to provide a kind of positioning cards region in the picture frame for card shooting of the applicationArt, to overcome drawbacks described above.
According to the embodiment of the application one aspect, a kind of method in positioning cards region is provided, including：It is being directed to cardTarget line section relevant to card border is determined in the predefined region of the picture frame of shooting；It combines the target line sectionQuadrangularly simultaneously therefrom determines candidate quadrangle；Determination is related to Serial No. in the specific region in the candidate quadrangleCandidate straightway；And the characteristic based on Serial No. relevant to candidate straightway, by the characteristic with the Serial No.The object quadrangle being consistent is positioned as card region.
According to an embodiment of the present application, in the method, the predefined region is based on the lead-frame on picture frameThe preset range of surrounding.
According to an embodiment of the present application, in the method, the determining and card side in the predefined region of described image frameThe relevant target line section of edge further comprises：Search the straightway in the predefined region in picture frame；And it will be with guidanceFour edges circle of frame are formed by angle and are determined as target line section less than the straightway of the first angle threshold value.
According to an embodiment of the present application, in the method, the straightway in the predefined region in picture frame is searched into oneStep includes：Straight line fitting is carried out to find straightway to the edge in predefined region using least square method.
According to an embodiment of the present application, in the method, it determines and counts in the specific region in candidate quadrangle respectivelyThe relevant candidate straightway of word sequence further comprises：Edge detection is carried out in the specific region of the quadrangle to obtain packetBianry image containing marginal information；It is relevant to numerical characteristic sequence to obtain that Hough transform is executed for the bianry imageStraightway；And candidate straightway relevant to numerical characteristic sequence is determined from straightway.
According to an embodiment of the present application, this method further comprises：Based on object quadrangle, obtain and the object quadrangleThe rectangular image of image phase mapping.
According to an embodiment of the present application, in the method, it is based on object quadrangle, is obtained and the object quadrangle image phaseThe rectangular image of mapping includes：Based on object quadrangle, the object quadrangle is obtained to rectangle and singly reflects matrix；And it is based onIt is described singly to reflect matrix, obtain the rectangular image with the object quadrangle image phase mapping.
According to the embodiment of the application another aspect, a kind of equipment in positioning cards region is provided, including：First line segment is trueCover half block, for determining target line relevant to card border in the predefined region of the picture frame for card shootingSection；Shape determination module, for the target line section combining quadrangularly and therefrom determining candidate quadrangle；Second line segmentDetermining module, for determining candidate straightway relevant to Serial No. in the specific region in the candidate quadrangle；WithAnd card locating module, for the characteristic based on Serial No. relevant to candidate straightway, by the spy with the Serial No.The object quadrangle that property is consistent is positioned as card region.
Compared with prior art, according to the technical solution of the application, by the characteristic of the Serial No. using card, thusThe validity of the multiple candidate quadrangles obtained under verifying complex background simultaneously finally determines card region, and then realizes in complexityEnvironmental background under positioning fast and accurately to card region.
Specific embodiment
To keep the purposes, technical schemes and advantages of the application clearer, below in conjunction with the application specific embodiment andTechnical scheme is clearly and completely described in corresponding attached drawing.Obviously, described embodiment is only the application oneSection Example, instead of all the embodiments.Based on the embodiment in the application, those of ordinary skill in the art are not doingEvery other embodiment obtained under the premise of creative work out, shall fall in the protection scope of this application.
The flow chart of the positioning cards region method according to the embodiment of the present application is shown with reference to Fig. 1, Fig. 1.
At step S110, target line section is determined in the predefined region of the picture frame for card shooting.
In the application scenarios of the application, for example, when user passes through such as portable computer, palm PC, mobile phoneEtc portable terminal when carrying out on-line payment and needing to input card number, the bank card information of validity period etc., Ke YitongThe image acquiring device such as camera of portable terminal is crossed to identify and input card information.Positioning cards are so just needed firstRegion.Therefore, it first has to determine target line section in the predefined region of the picture frame for card shooting.
Determine that the process of target line section is as shown in Figure 2.For example, can search at step 201 for card shootingThen the straightway in predefined region in picture frame will be formed at step 202 with four edges circle of predefined regionAngle is determined as target line section less than the straightway of the first angle threshold value.Wherein, predefined region is based on picture frameThe preset range of the surrounding of lead-frame.Wherein, which is virtual and is covered on captured picture frame.Wherein,Least square method can be used, straight line fitting is carried out to find straightway to the edge in predefined region.
Specifically, by taking bank card as an example, such as need to shoot the bank card and to the position of the bank card in picture frameSet and positioned, then in shooting form using lead-frame (lead-frame can be with it is card-like adaptable, such as canTo be rectangle) as guidance, it can attempt for card to be aligned with the lead-frame on display window when shooting bank card.MoreSpecifically, display window will show camera taken by scene, lead-frame will with OSD (On Screen Display withScreen display technology) mode is superimposed upon on shown real-time video, to form a lead-frame.User's dollying head orTaken card image is aligned by card, trial with lead-frame, in the process continuous acquisition video frame and canTo choose arbitrary image frame in the video frame and carry out edge detection to its predefined region, and using least square method to edgeTesting result carries out straight line fitting, and will be formed by angle less than the first angle threshold value with four edges circle of guidance fieldStraightway is determined as target line section.It is 20 degree that first angle threshold value, which for example can choose,.
After finding target line section, this method proceeds to step 102.At step 102, by the target lineDuan Zuhe quadrangularly simultaneously therefrom determines candidate quadrangle.
Specifically, being combined into possible all quadrangles according to the target line section found at step 101.It connects, all quadrangles can be screened again.For example, if the adjacent side angle of a quadrangle is less than second angle threshold value,Then filtered out.The second angle threshold value range for example can choose as any degree in 70 degree to 110 degree.It finally screensSatisfactory one or more candidate quadrangles out.Record four vertex positions of one or more of candidate quadrangles withStandby subsequent use.
At step 103, candidate straightway relevant to Serial No. is determined in the specific region in candidate quadrangle.
Specifically, it is possible, firstly, to carrying out edge detection in the specific region of candidate quadrangle to obtain includes edgeThen the bianry image of information executes Hough transform for the bianry image to obtain straightway relevant to Serial No..Wherein, the specific region can be region associated with the Serial No. in candidate quadrangle.For example, being with bank cardExample, the specific region are region locating for bank card number.
Based on straightway obtained, filter out length it is too short and with the excessive line segment of angle following on candidate quadrangle fromAnd candidate straightway relevant to Serial No. is determined from above-mentioned straightway.For example, length is more than 1/2 length of lead-frame long sideThe straightway of degree will be deleted.For example, if straightway and candidate quadrangle are formed by angle and are greater than 10 degree, the straightwayAlso it will be deleted.By the above-mentioned means, the remaining straightway detected is as candidate straightway relevant to Serial No..ItsIn, which is that the top edge of Serial No. and lower edge are formed by two lines section.
Selection in above each paragraph about the length of straightway and angle is only the optional example of the application, this ShenPlease be without being limited thereto, but other selections appropriate can also be carried out as required.
At step 104, based on the characteristic of Serial No. relevant to candidate straightway, by the spy with the Serial No.The object quadrangle that property is consistent is positioned as card region.
Specifically, candidate straightway relevant to Serial No. is obtained at step 103, for example, with bank cardThe relevant candidate straightway of card number sequence.It then, will as shown in figure 3, based on candidate straightway and according to the characteristic of Serial No.The object quadrangle being consistent with the characteristic of the Serial No. is positioned as card region.Fig. 3 is schematically shown according to this ShenPlease embodiment positioning object quadrangle schematic diagram.
Based on Serial No. relevant to candidate straightway, using the validity of the property verification quadrangle of Serial No.,All quadrangles for not meeting the characteristic are filtered out, the object quadrangle being consistent with the characteristic of the Serial No. is positioned as cardRegion.Specifically, the characteristic of Serial No. relevant to candidate straightway that is to say the perspective projection characteristic.Perspective projection is specialProperty refer to that the vanishing point of the top edge of numeric area and the constituted line segment of lower edge and card face position are formed by quadrangleThe vanishing point on two sides up and down be overlapped (in the case where parallel, vanishing point appears in infinity), and above and below numeric areaThe angle that edge is formed should be less than the angle for being equal to two sides of quadrangle or more.In other words, candidate straightway and four side of targetMeet perspective projection characteristic between shape, is consistent therewith to be determined using perspective projection characteristic relevant to candidate straightwayObject quadrangle.Therefore, it is based on mentioned above principle, is filtered out and is not met the extra line segment of perspective projection characteristic and be formed by quadrangle,Obtain object quadrangle.
It is to be herein pointed out above embodiment is all but the in fact, scheme in the application by taking bank card as an exampleBe not limited to bank card, but can be applied to standard compliant various standard cards, such as identity card, member card etc..
According to the method for the embodiment of the present application, it can further include based on object quadrangle, obtain and the quadrangle figureAs the rectangular image of phase mapping.Based on object quadrangle, object quadrangle is obtained to rectangle and singly reflects matrix, be then based on describedMatrix is singly reflected, the rectangular image with the object quadrangle image phase mapping is obtained.
Fig. 4 schematically shows card image is normalized to rectangle by object quadrangle according to the embodiment of the present applicationStep schematic diagram.Since known target card is rectangle, the object quadrangle that solution previous step detects to rectangleMatrix is singly reflected, matrix is singly reflected by this, the mapping of object quadrangle image is become into a rectangular image, which is exactly to rectifyCard image after just.Mapping equation is as follows：
pb=Habpa
In above-mentioned each equation, wherein pbFor the point in original image, the i.e. point of object quadrangle, paAfter correctionPoint in image, the i.e. point of rectangle, by four vertex positions (xa0, ya0) of the normalized image after preset correction, (xa1,Ya1), four vertex positions (xb0, yb0) of the card positioned in (xa2, ya2), (xa3, ya3) and original image, (xb1,Yb1), (xb2, yb2), (xb3, yb3) bring above formula solution linear equation into, obtain matrix Hab.It then will be each after correctionPoint position is mapped back in original image by above-mentioned formula.Assuming that (xan, yan) corresponding points (xbn, ybn), the value of n are respectively0,1,2 and 3, then the pixel value of (xbn, ybn) can be indicated with the bilinear interpolation of (xan, yan).
So far, it has been described that the positioning cards region method in the picture frame for card shooting of the embodiment of the present applicationFlow chart.
According to an embodiment of the present application, a kind of equipment 500 for positioning cards region is also provided, as shown in figure 5, Fig. 5For according to a kind of structural block diagram in positioning cards region in the picture frame for card shooting of the embodiment of the present application.The equipmentMay include：First line segment determining module 510, shape determination module 520, second line segment determining module 530 and card positioningModule 540.
First line segment determining module 510 can be used for determining and card border phase in the predefined region of described image frameThe target line section of pass, wherein the predefined region is the preset range of the surrounding based on the lead-frame on picture frame.ShapeDetermining module 520 can be used for combining the target line section quadrangularly and therefrom determine candidate quadrangle.Second line segmentDetermining module 530 can be used in the specific region in the candidate quadrangle determining candidate straight line relevant to Serial No.Section；And card locating module 540 can be used for based on candidate straightway and according to the characteristic of Serial No., it will be with the numberThe object quadrangle that the characteristic of sequence is consistent is positioned as card region.
According to the equipment of the embodiment of the present application, the first line segment determining module 510, which may further include, searches submodule 511Submodule 512 is determined with the first line segment, wherein searching submodule 511 can be used for searching in the predefined region in picture frameStraightway, search submodule 511 using least square method in predefined region edge carry out straight line fitting to findStraightway.First line segment determines that submodule 512 can be used for that angle will be formed by less than first with four edges circle of lead-frameThe straightway of angle threshold value is determined as target line section.
According to the equipment of the embodiment of the present application, second line segment determining module 530 may further include detection sub-module531, transformation submodule 532 and second line segment determine submodule 533.Wherein, detection sub-module 531 can be used on four sideEdge detection is carried out in the specific region of shape to obtain the bianry image comprising marginal information, transformation submodule 532 can be used forHough transform is executed for the bianry image to obtain straightway relevant to numerical characteristic sequence；And second line segment is trueDetermining detection sub-module 533 can be used for determining candidate straightway relevant to numerical characteristic sequence from straightway.
According to the equipment of the embodiment of the present application, it can further include and obtain module (not shown), obtaining module can be withFor being based on object quadrangle, the rectangular image with the object quadrangle image phase mapping is obtained.
According to the equipment of the embodiment of the present application, obtaining module may include that the first acquisition submodule and second obtain submoduleBlock, wherein the first acquisition submodule can be used for being obtained the object quadrangle based on object quadrangle to rectangle and singly being reflected squareBattle array.Second acquisition submodule is used for based on the rectangular image for singly reflecting matrix, obtaining with the object quadrangle image phase mapping.
Since the function that the equipment of the present embodiment is realized essentially corresponds to earlier figures 1 to embodiment of the method shown in fig. 5,Therefore not detailed place in the description of the present embodiment, it may refer to the related description in previous embodiment, this will not be repeated here.
In a typical configuration, calculating equipment includes one or more processors (CPU), input/output interface, netNetwork interface and memory.
Memory may include the non-volatile memory in computer-readable medium, random access memory (RAM) and/orThe forms such as Nonvolatile memory, such as read-only memory (ROM) or flash memory (flash RAM).Memory is computer-readable mediumExample.
Computer-readable medium includes permanent and non-permanent, removable and non-removable media can be by any methodOr technology come realize information store.Information can be computer readable instructions, data structure, the module of program or other data.The example of the storage medium of computer includes, but are not limited to phase change memory (PRAM), static random access memory (SRAM), movesState random access memory (DRAM), other kinds of random access memory (RAM), read-only memory (ROM), electric erasableProgrammable read only memory (EEPROM), flash memory or other memory techniques, read-only disc read only memory (CD-ROM) (CD-ROM),Digital versatile disc (DVD) or other optical storage, magnetic cassettes, tape magnetic disk storage or other magnetic storage devicesOr any other non-transmission medium, can be used for storage can be accessed by a computing device information.As defined in this article, it calculatesMachine readable medium does not include temporary computer readable media (transitory media), such as the data-signal and carrier wave of modulation.
It should also be noted that, the terms "include", "comprise" or its any other variant are intended to nonexcludabilityIt include so that the process, method, commodity or the equipment that include a series of elements not only include those elements, but also to wrapInclude other elements that are not explicitly listed, or further include for this process, method, commodity or equipment intrinsic wantElement.In the absence of more restrictions, the element limited by sentence "including a ...", it is not excluded that including described wantThere is also other identical elements in the process, method of element, commodity or equipment.
It will be understood by those skilled in the art that embodiments herein can provide as method, system or computer program product.Therefore, complete hardware embodiment, complete software embodiment or embodiment combining software and hardware aspects can be used in the applicationForm.It is deposited moreover, the application can be used to can be used in the computer that one or more wherein includes computer usable program codeThe shape for the computer program product implemented on storage media (including but not limited to magnetic disk storage, CD-ROM, optical memory etc.)Formula.
The above description is only an example of the present application, is not intended to limit this application.For those skilled in the artFor, various changes and changes are possible in this application.All any modifications made within the spirit and principles of the present application are equalReplacement, improvement etc., should be included within the scope of the claims of this application.