JP5858012B2 - Image processing apparatus, image processing method, and program - Google Patents

Description

  The present invention relates to an image processing apparatus, an image processing method, and a program.

2. Description of the Related Art Conventionally, an apparatus that generates code information in which predetermined information is encoded in a regular array of pixel sets is known (see, for example, Patent Document 1).
The code information is imaged by an imaging device such as a mobile phone or a smartphone while being formed on a recording medium such as paper. The imaging apparatus obtains original predetermined information represented by the code information by performing a predetermined decoding process on the image information of the captured code information.

JP 2007-118316 A

By the way, when imprinting the seal on a recording medium such as paper using a seal in which the code information is formed in a polygonal frame around another image, a force is applied to the entire surface of the stamp surface substantially evenly. Otherwise, the imprint frame may be distorted or the imprint may be blurred or blurred. Further, the frame may be distorted by heat treatment when the code information is formed on the frame.
As a result, it becomes impossible to detect the vertex of the frame from the imprint image obtained by capturing the imprint, and the projective transformation process for converting the imprint image into the polygonal image of the original seal cannot be performed properly. is there. As a result, it becomes impossible to properly read predetermined information from the code information of the seal image.

  The present invention has been made in view of such problems, and an object of the present invention is to provide an image processing apparatus, an image processing method, and a program capable of appropriately detecting a frame portion from an image obtained by capturing an imprint. Is to provide.

In order to solve the above problems, an image processing apparatus according to the present invention provides:
An acquisition unit that acquires an imprint image obtained by capturing an imprint in which code information is added to a polygonal frame portion; and an outer contour of the frame portion is configured in the imprint image acquired by the acquisition unit, and the polygon shape Estimation means for estimating a predetermined number of straight lines according to the number of corners of the frame, and detection means for detecting the frame portion of the imprint image composed of the predetermined number of straight lines estimated by the estimation means. It is characterized by that.

The image processing method according to the present invention includes:
An image processing method using an image processing device, a process for acquiring an imprint image obtained by capturing an imprint in which code information is added to a polygonal frame portion, and an outside of the frame portion in the acquired imprint image A process for configuring a contour and estimating a predetermined number of straight lines according to the number of corners of the polygonal frame; and a process for detecting the frame part of the imprint image composed of the estimated predetermined number of straight lines; It is characterized by including.

The program according to the present invention is
The computer of the image processing apparatus obtains an imprint image obtained by capturing an imprint in which code information is added to a polygonal frame portion, and the outer contour of the frame portion is obtained in the imprint image obtained by the acquisition means. And detecting means for detecting the frame portion of the imprint image composed of a predetermined number of straight lines estimated by the estimating means. It is characterized by functioning as a means.

  According to the present invention, it is possible to appropriately detect a frame portion from an image obtained by capturing an imprint.

It is a block diagram which shows schematic structure of the portable terminal of one Embodiment to which this invention is applied. It is a flowchart which shows an example of the operation | movement which concerns on the code reading process by the portable terminal of FIG. It is a figure for demonstrating the code reading process of FIG. It is a figure which shows typically an example of the image which concerns on the code reading process of FIG. It is a figure which shows typically an example of the image which concerns on the code reading process of FIG. It is a figure which shows typically an example of the image which concerns on the code reading process of FIG. It is a figure which shows typically an example of the image which concerns on the code reading process of FIG. It is a block diagram which shows schematic structure of the portable terminal of the modification 1 to which this invention is applied. It is a flowchart which shows an example of the operation | movement which concerns on the code reading process by the portable terminal of FIG. It is a figure which shows typically an example of the image which concerns on the code reading process of FIG. It is a figure which shows typically an example of the image which concerns on the code reading process of FIG.

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. However, the scope of the invention is not limited to the illustrated examples.

FIG. 1 is a block diagram showing a schematic configuration of a mobile terminal 100 according to an embodiment to which the present invention is applied.
As shown in FIG. 1, the mobile terminal 100 includes a central control unit 1, a memory 2, an imaging unit 3, an imaging control unit 4, an image data generation unit 5, a code processing unit 6, and an operation processing unit 7. A display unit 8, a display control unit 9, a transmission / reception unit 10, a communication control unit 11, an operation input unit 12, and the like.
The central control unit 1, the memory 2, the imaging unit 3, the imaging control unit 4, the image data generation unit 5, the code processing unit 6, the operation processing unit 7, the display control unit 9, the transmission / reception unit 10, and the communication control unit 11 Are connected via a bus line 13.

  Note that the mobile terminal 100 includes, for example, an imaging device, a mobile station used in a mobile communication network such as a mobile phone or a PHS (Personal Handy-phone System), a PDA (Personal Data Assistants), and the like.

  The central control unit 1 controls each unit of the mobile terminal 100. Specifically, the central control unit 1 includes a CPU (Central Processing Unit; not shown) that controls each part of the mobile terminal 100, and performs various control operations according to various processing programs (not shown) for the mobile terminal 100. Do.

  The memory 2 is composed of, for example, a DRAM (Dynamic Random Access Memory) or the like. The memory 2 includes a buffer memory that temporarily stores data processed by the central control unit 1 and the code processing unit 6, a working memory such as the central control unit 1, and various types of functions related to the function of the mobile terminal 100. A program memory (not shown) in which programs and data are stored is provided.

The imaging unit 3 images the seal Si (see FIG. 3A) of the seal S stamped on the recording medium P.
In the seal S, a polygonal frame (for example, a square shape) is formed around a predetermined mark for leaving the imprint Si on the recording medium P, and predetermined information is arranged in a regular array of pixel sets in the frame. The encoded code information Sc is shaped so as to be added to the frame portion Sw of the seal imprint Si.

The imprint Si is left on the recording medium P when the stamp S is imprinted on the recording medium P, and a frame portion Sw corresponding to a polygonal frame is left around the stamp image Sp formed on the stamp surface. .
A plurality of code information Sc obtained by encoding predetermined information into a regular array of pixel sets is added to the frame portion Sw. That is, in the frame portion Sw, the code information Sc is added to at least two sides Sa, Sa among the plurality of sides Sa,. Specifically, the same code information Sc is added to each of the four sides Sa of the substantially square frame portion Sw in a direction that is symmetrical with respect to the diagonal line. That is, the code information Sc is embedded in the seal impression Si in a multiple manner. In addition, a marker Sm having a predetermined shape (for example, a square shape) used for detecting the vertex C is added to each of the four corners of the square frame portion Sw.
The code information Sc is, for example, the extending direction of the side Sa (substantially in the width direction) at a substantially central side in the width direction of each side Sa of the frame portion Sw from a position spaced from the marker Sm at a predetermined position. (Orthogonal direction orthogonal to each other) is added in a predetermined direction.
Here, the code information Sc is obtained by encoding original predetermined information (for example, URL) according to a predetermined encoding format (for example, Reed-Solomon code, Golay code, etc.). For example, in the code information Sc, a set of white pixels having a pixel value “1” and a set of black pixels having a pixel value “0” are regularly arranged with a predetermined number of dimensions.

  In the present embodiment, when the stamp S is stamped on the recording medium P, it is assumed that the stamp S is stamped in a state where no force is applied substantially evenly on the entire surface of the stamp. For this reason, for example, a part of the frame part Sw of the imprint Si (for example, the lower part in FIG. 4A) swells, and a part of the imprint Si (for example, the upper left part in FIG. 4A). Fading has occurred.

The imaging unit 3 includes a lens unit 3a and an electronic imaging unit 3b.
The lens unit 3a includes a plurality of lenses such as a zoom lens and a focus lens.
The electronic imaging unit 3b is composed of, for example, an image sensor such as a charge coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS), and converts an optical image that has passed through various lenses of the lens unit 3a into a two-dimensional image signal. To do.
In addition, although illustration is abbreviate | omitted, the imaging part 3 may be provided with the aperture_diaphragm | restriction which adjusts the quantity of the light which passes the lens part 3a.

The imaging control unit 4 controls the imaging of the subject by the imaging unit 3. That is, the imaging control unit 4 includes a timing generator, a driver, and the like, although not illustrated. Then, the imaging control unit 4 scans and drives the electronic imaging unit 3b with a timing generator and a driver, converts the optical image into a two-dimensional image signal with the electronic imaging unit 3b at a predetermined period, and the electronic imaging unit 3b. The frame image is read out from the imaging area for each screen and is output to the image data generation unit 5.
In addition, the imaging control unit 4 performs adjustment control of imaging conditions of the subject such as AF (automatic focusing process), AE (automatic exposure process), AWB (automatic white balance), and the like.

  The image data generation unit 5 appropriately adjusts the gain for each color component of RGB with respect to the analog value signal of the frame image transferred from the electronic image pickup unit 3b, and then samples and holds it by a sample hold circuit (not shown). The digital signal is converted into digital data by a / D converter (not shown), color processing including pixel interpolation processing and γ correction processing is performed by a color process circuit (not shown), and then a digital luminance signal Y and color difference signal Cb , Cr (YUV data).

  Then, the image data generation unit 5 sequentially outputs the generated YUV data of each frame image to the memory 2 and stores it in the memory 2.

The code processing unit 6 includes an image acquisition unit 6a, a binarization unit 6b, a straight line estimation unit 6c, a frame detection unit 6d, and an information reading unit 6e.
Each unit of the code processing unit 6 is configured by, for example, a predetermined logic circuit, but the configuration is an example and is not limited thereto.

The image acquisition unit 6a sequentially acquires captured images Ia (see FIG. 4A) in which the imprint Si imprinted on the recording medium P is captured.
That is, the image acquisition unit (acquisition unit) 6a acquires a captured image (imprinted image) Ia obtained by imaging the imprint Si in which the code information Sc is added to the frame portion Sw having a predetermined width around the predetermined imprinted image Sp. To do. Specifically, the image acquisition unit 6 a acquires from the memory 2 a copy of image data having a predetermined resolution of the captured image Ia generated by the image data generation unit 5 after the impression Si is imaged by the imaging unit 3.

The binarization unit 6b generates a first binarized image Ib (see FIG. 4B).
That is, the binarization unit 6b binarizes the luminance component Y of the image data (YUV data) of the captured image Ia acquired by the image acquisition unit 6a with a predetermined threshold (for example, Image data of the first binarized image Ib is generated by performing an adaptive binarization process or the like.
In addition, the binarization unit 6b generates a second binarized image Id (see FIG. 6C). That is, the binarization unit 6b binarizes the luminance component Y of the image data (YUV data) of the projection-converted image Ic generated by the projection conversion unit d2 of the frame detection unit 6d with a predetermined threshold. Binarization processing (for example, adaptive binarization processing or the like) is performed to generate image data of the second binarized image Id.
Note that the above binarization process is a known technique, and thus detailed description thereof is omitted here.

  The straight line estimation unit (estimating means) 6c configures the outer contour of the frame portion Sw corresponding to the polygonal frame of the seal S in the captured image Ia acquired by the image acquisition unit 6a, and the corners of the polygonal frame A predetermined number of straight lines L corresponding to the number is estimated. Specifically, the straight line estimation unit 6c includes a contour specifying unit c1 and a straight line specifying unit c2.

The contour specifying unit c1 specifies a polygonal convex hull region A1 corresponding to the outer contour of the frame portion Sw of the imprint Si.
That is, the contour specifying unit (first specifying unit) c1 is a polygonal convex hull region A1 corresponding to the outer contour of the frame portion Sw of the captured image Ia acquired by the image acquiring unit 6a (see FIG. 4C). Is identified.
Specifically, the contour specifying unit c1 acquires, for example, the image data of the first binarized image Ib corresponding to the captured image Ia generated by the binarizing unit 6b, and is convex with respect to the image data. By performing the hull process, for each set of black pixels having a pixel value “0” within a predetermined range, a plurality of line segments connecting the pixels constituting the outermost contour are calculated. As a result, a black pixel having a pixel value “0” within a predetermined range is in a state of being wrapped by a plurality of line segments, and a polygonal region formed by these line segments is defined as a convex hull region A having no recesses. Become. At this time, the contour specifying unit c1 forms a plurality of convex hull regions A by changing the range to be processed in the binarized image.
Then, the contour specifying unit c1 has a convex hull region A having the largest area among the plurality of convex hull regions A,... That corresponds to the outer contour of the frame portion Sw of the imprint Si (for example, Hexagonal convex hull region A1.
Note that the content of the convex hull processing described above is an example and is not limited to this, and can be arbitrarily changed as appropriate. Further, since the convex hull region A is a known technique, detailed description thereof is omitted here.

The straight line specifying unit c2 specifies a predetermined number of straight lines L constituting the outer contour of the frame image Wa corresponding to the frame portion Sw of the seal impression Si (see FIG. 6A).
That is, the straight line specifying unit (second specifying unit) c2 includes a plurality of (for example, six) vertices B constituting the convex hull region A1 having a polygonal shape (for example, hexagonal shape) specified by the contour specifying unit c1,. The predetermined number of straight lines (for example, four straight lines forming a square outer contour) L that specify the outer contour of the frame image Wa are specified on the basis of the positions. Specifically, the straight line specifying unit c2 includes each straight line L and a polygonal convex hull among a plurality of straight lines L passing through any two vertices B, B constituting the polygonal convex hull region A1. A predetermined number of straight lines L constituting the outer contour of the frame image Wa are specified based on at least one of the number of pixels that overlap with the area A1 and the relative relationship between the adjacent straight lines L.

That is, the straight line specifying part c2 is a polygonal convex line among a plurality of straight lines L passing through any two vertices B, B constituting the polygonal convex hull region A1 specified by the outline specifying part c1. A straight line L in which the number of overlapping pixels constituting the enveloping area A1 is greater than a predetermined value is specified, and the straight line L is specified as a straight line L that forms the outer contour of the frame image Wa.
Specifically, for example, the straight line specifying unit c2 performs a straight line detection process by the RANSAC method on the pixels forming the polygonal convex hull region A1 specified by the contour specifying unit c1, thereby the frame image Wa. A straight line L constituting the outer contour is identified. For example, the straight line specifying unit c2 selects any two vertices B, B from the six vertices B constituting the convex hull region A1, and connects the two vertices B, B. Is identified as a candidate for a straight line L (candidate straight line L) constituting the square outer contour of the frame image Wa. Then, the straight line specifying unit c2 calculates the number of pixels that overlap with a plurality of pixels constituting the convex hull region A1 for all the specified candidate straight lines L, and the number of calculated pixels is larger than a predetermined value. The straight line L is specified as the straight line L constituting the outer contour of the frame image Wa. As a result, for example, a candidate straight line La corresponding to a portion where the imprint Si is blurred or a candidate straight line Lc other than the relatively short candidate straight line Lb is specified as the straight line L constituting the outer contour of the frame image Wa. (See FIG. 5 (a)).
Note that the straight line detection process by the RANSAC method is a known technique, and thus detailed description thereof is omitted here.

Further, the straight line specifying part c2 is a line L adjacent to one another among a plurality of straight lines L passing through any two vertices B, B constituting the polygonal convex hull region A1 specified by the contour specifying part c1. A straight line L that is substantially equal to the interior angle of the polygonal frame is specified, and the pixels that form the straight line L are weighted to the pixels that overlap the polygonal convex hull region A1, and each straight line L is evaluated. The value is calculated, and the straight line L with the high evaluation value is specified as the straight line L constituting the outer contour of the frame image Wa.
Specifically, for example, the straight line specifying unit c2 calculates candidate straight lines Ld that are substantially equal to the interior angle (90 °) of the square frame of the seal S with respect to all candidate straight lines L. Identify. Then, the straight line specifying unit c2 weights pixels that overlap the polygonal convex hull region A1 among the pixels constituting the specified candidate straight line Ld, and calculates an evaluation value for each candidate straight line L according to a predetermined arithmetic expression. calculate. For example, when a part of the frame image Wa of the imprint Si (for example, the lower part in FIG. 5B) is swollen, the straight line specifying part c2 is one of the three vertices B of the part. When the two vertices B and B are selected and the candidate straight line L is specified, the three candidate straight lines L,... Are specified. Then, the straight line specifying unit c2 has, for each of these three candidate straight lines L,..., Adjacent candidate straight lines L (two left and right candidate straight lines Lc represented by two-dot chain lines in FIG. 5B). ) And a candidate straight line L (candidate straight line Ld represented by a one-dot chain line in FIG. 5B) that is substantially equal to 90 ° is specified. Furthermore, the straight line specifying unit c2 selects pixels overlapping the polygonal convex hull region A1 among the pixels constituting the specified candidate straight line Ld (for example, the pixels on the left and right ends in FIG. 5B). An identification value is specified, and an evaluation value is calculated according to a predetermined arithmetic expression with a weight assigned to the identified pixel.
Then, the straight line specifying unit c2 compares the calculated evaluation values of the candidate straight lines L, and specifies the candidate straight line Ld having the highest evaluation value as the straight line L constituting the outer contour of the frame image Wa. For example, the candidate straight line Ld represented by the alternate long and short dash line does not form a shape along the edge of the polygonal convex hull region A1, but the pixels on the left and right ends overlap the polygonal convex hull region A1, The evaluation value is higher than that of the other candidate straight line Lb represented by the broken line, and is specified as a straight line L constituting the outer contour of the frame image Wa.

  In this way, the straight line estimation unit 6c includes the four straight lines L constituting the outer contour of the frame image Wa corresponding to the square frame of the seal S in the captured image Ia (first binarized image Ib). Estimate. Specifically, the straight line estimation unit 6c estimates an upper-side corresponding straight line L1, a lower-side corresponding straight line L2, a left-side corresponding straight line L3, and a right-side corresponding straight line L4 as straight lines L corresponding to the upper, lower, left, and right sides of the square (FIG. 6). (See (a)).

  The frame detection unit (detection unit) 6d detects the frame image Wa of the captured image Ia of the impression Si composed of a predetermined number of straight lines L estimated by the straight line estimation unit 6c. Specifically, the frame detection unit 6d includes a vertex specifying unit d1 and a projective transformation unit d2.

The vertex specifying unit d1 specifies the vertex C of the frame image Wa of the captured image Ia (see FIG. 6B).
That is, the vertex specifying unit (third specifying unit) d1 uses a predetermined number of points C where the predetermined number of straight lines L intersected by the straight line specifying unit c2 intersect with each other as the vertex C of the frame portion Sw (frame image Wa) of the imprint Si. As specified. Specifically, the vertex specifying part d1 is formed by the adjacent straight lines L of the four straight lines L,... Constituting the outer contour specified by the straight line specifying part c2 intersecting in the captured image Ia. These four points are specified as vertices C of the frame image Wa. At this time, for the straight lines L that do not intersect each other (for example, the upper side corresponding straight line L1 and the left side corresponding straight line L3) among the four straight lines L,... The intersection is obtained by extending to.
Then, the frame detection unit 6d detects the frame image Wa of the captured image Ia based on the predetermined number of vertices C specified by the vertex specification unit d1. That is, the frame detection unit 6d detects an area having the specified four points as vertices C,... As a frame portion Sw (frame image Wa) of the imprint Si.

The vertex specifying unit d1 may specify the vertex C of the frame portion Sw (frame image Wa) based on the coordinate position of the marker image Ma corresponding to the marker Sm of the imprint Si in the captured image Ia.
That is, for example, as shown in FIG. 7A, when blur occurs in a part (for example, the upper right part) of the imprint Si, the part becomes a black pixel having a pixel value of “0” when binarized. Therefore, there is a possibility that the straight line L constituting the outer contour of the frame image Wa cannot be properly estimated from the captured image Ia of the imprint Si. Therefore, the vertex specifying unit d1 takes into account the coordinate position of the marker image Ma in the captured image Ia by utilizing the fact that the vertex of the polygonal frame exists in the vicinity (within a predetermined range) of the marker Sm on the stamp surface. The vertex C of the frame image Wa is specified.
Specifically, for example, the vertex specifying unit d1 prepares a pattern image Pa (see FIG. 7B) corresponding to the shape of the marker Sm, and features information (for example, SIFT (Scale-Invariant) of the pattern image Pa. A region including a marker image Ma similar to the pattern image Pa in the captured image Ia is specified using the Features Transform). And the vertex specific | specification part d1 specifies the vertex C of the frame image Wa from the predetermined range on the basis of the coordinate position of the marker image Ma in the captured image Ia. Thereby, the vertex specifying unit d1 can specify the vertex C of the corresponding frame image Wa from the portion where the imprint Si is blurred, and the frame detection unit 6d can appropriately detect the frame image Wa of the captured image Ia. (See FIG. 7C).

The projective transformation unit d2 performs a projective transformation process for generating a projected transformed image Ic (see FIG. 6B).
That is, the projective transformation unit (generation unit) d2 performs a projective transformation process on the captured image Ia acquired by the image acquisition unit 6a on the basis of the predetermined number of vertices C specified by the vertex specifying unit d1, and performs polygon conversion. A projective transformed image Ic of the shape is generated. Specifically, the projective transformation unit d2 has a coordinate position of four vertices C,... Of a square frame image Wa having a distorted outer shape specified by the vertex specifying unit d1. A coordinate conversion formula is calculated so that the coordinate position becomes. Then, the projective transformation unit d2 performs a projective transformation process on the captured image Ia of the imprint Si in accordance with the calculated coordinate transformation formula, and the outline of the frame image Wa corresponding to the frame portion Sw of the imprint Si is the original seal. A projective transformed image Ic converted into a square shape of S is generated.
Then, the frame detection unit 6d selects a square frame portion Sw (frame image Wa) corresponding to the frame of the seal S in the projection-converted image Ic (polygonal captured image) generated by the projection conversion unit d2. To detect.
Note that the above-described projective transformation process is a known technique, and thus detailed description thereof is omitted here.

The information reading unit 6e performs a reading process of reading original predetermined information from the code information Sc.
That is, the information reading unit (reading unit) 6e reads predetermined information from the code information Sc in the frame portion Sw (frame image Wa) of the captured image Ia of the seal impression Si detected by the frame detection unit 6d. Specifically, the information reading unit 6e reads predetermined information from the code information Sc in the frame image Wa of the second binarized image Id corresponding to the projection-converted image Ic generated by the projection conversion unit d2.
For example, the information reading unit 6e detects two substantially parallel edges constituting the frame image Wa detected by the frame detection unit 6d in the second binarized image Id, and an intermediate between these two edges. A line having a predetermined shape (for example, a square shape) formed by connecting the dots is specified as the reading area D of the code information Sc (see FIG. 6C). Then, the information reading unit 6e scans along a predetermined direction from a predetermined position (for example, the upper left corner) of the reading region D, and collects a set of white pixels having a pixel value “1” and black having a pixel value “0”. Each coordinate position where a set of pixels exists is specified. The information reading unit 6e performs a decoding process on the specified array of white pixels and black pixels according to the encoding method of the code information Sc, and performs the original predetermined process represented by the code information Sc. Information (for example, URL) is read.
At this time, the information reading unit 6e performs a reading process for each area corresponding to each side Sa of the frame portion Sw in the reading area D. That is, the original predetermined information is read from the code information Sc a number of times (for example, four times) corresponding to the number of sides Sa of the frame portion Sw. Here, since the same code information Sc is added to each side Sa of the frame portion Sw, the information reading unit 6e detects, for example, a plurality of original predetermined information detected at two or more locations. In this case, it may be configured to determine that the predetermined information has been properly read.
Note that the above reading process is a known technique, and thus detailed description thereof is omitted here.

The operation processing unit 7 performs a predetermined operation according to the original predetermined information of the code information Sc read by the information reading unit 6e.
That is, the operation processing unit (processing unit) 7 controls execution of processing corresponding to the predetermined information when the information reading unit 6e reads a predetermined number or more of the predetermined information. Specifically, for example, when a URL is read as predetermined information, the operation processing unit 7 controls the communication control unit 11 to display a specific page on the Internet defined by the acquired URL. to access. Then, the operation processing unit 7 controls the display control unit 9, the transmission / reception unit 10, and the like in accordance with execution instructions for various types of processing set in advance (for example, playback of specific audio or images). Is executed.

  The display unit 8 is composed of, for example, a liquid crystal display panel, and displays an image (for example, a live view image) captured by the imaging unit 3 based on a video signal from the display control unit 9 on a display screen.

The display control unit 9 performs control to read out display image data temporarily stored in the memory 2 and display it on the display unit 8.
Specifically, the display control unit 9 includes a VRAM (Video Random Access Memory), a VRAM controller, a digital video encoder, and the like. The digital video encoder reads the luminance signal Y and the color difference signals Cb and Cr read from the memory 2 and stored in the VRAM (not shown) under the control of the central control unit 1 through the VRAM controller. Are read out at a predetermined playback frame rate (for example, 30 fps), and a video signal is generated based on these data and output to the display unit 8.
For example, the display control unit 9 performs live updating on the display unit 8 while sequentially updating a plurality of frame images captured by the imaging unit 3 and the imaging control unit 4 and generated by the image data generation unit 5 at a predetermined display frame rate. Display the view.

The transmitter / receiver unit 10 performs a call with an external user of an external device connected via the communication network N.
Specifically, the transmission / reception unit 10 includes a microphone 10a, a speaker 10b, a data conversion unit 10c, and the like. The transmission / reception unit 10 performs A / D conversion processing on the user's transmission voice input from the microphone 10a by the data conversion unit 10c and outputs the transmission voice data to the central control unit 1. Under the control, voice data such as received voice data outputted and inputted from the communication control unit 11 is D / A converted by the data conversion unit 10c and outputted from the speaker 10b.

The communication control unit 11 transmits and receives data via the communication network N and the communication antenna 11a.
That is, the communication antenna 11a is connected to a predetermined communication method (for example, W-CDMA (Wideband Code Division Multiple Access) method, GSM (Global System)) used by the mobile terminal 100 for communication with a radio base station (not shown). for Mobile Communications (registered trademark) system, etc.). The communication control unit 11 transmits / receives data to / from the radio base station via the communication antenna 11a through a communication channel set in the communication method according to a communication protocol corresponding to a predetermined communication method. That is, the communication control unit 11 transmits / receives voice during a call with an external user of the external device to the external device of the communication partner based on the instruction signal output from the central control unit 1 and input, Send and receive e-mail data.
Note that the configuration of the communication control unit 11 is an example and is not limited thereto, and can be arbitrarily changed as appropriate. For example, although not shown, a wireless LAN module is mounted and an access point (Access Point) is provided. It is good also as a structure which can access the communication network N via this.

The communication network N is a communication network that connects the mobile terminal 100 to an external device via a wireless base station, a gateway server (not shown), or the like, for example.
The communication network N is a communication network constructed using, for example, a dedicated line or an existing general public line, and various line forms such as a LAN (Local Area Network) and a WAN (Wide Area Network) are applied. Is possible. The communication network N includes, for example, various communication network networks such as a telephone line network, ISDN line network, dedicated line, mobile communication network, communication satellite line, CATV line network, IP network, VoIP (Voice over Internet Protocol). ) Gateways, Internet service providers, etc. are included.

The operation input unit 12 is for inputting various instructions to the terminal body.
Specifically, the operation input unit 12 executes a shutter button related to a subject photographing instruction, up / down / left / right cursor buttons and a determination button related to a selection instruction of a mode, a function, etc., making / receiving a call, sending / receiving an e-mail, etc. Various buttons (not shown) such as communication-related buttons related to instructions and numeric buttons and symbol buttons related to text input instructions are provided.
When various buttons are operated by the user, the operation input unit 12 outputs an operation instruction corresponding to the operated button to the central control unit 1. The central control unit 1 causes each unit to execute a predetermined operation (for example, imaging of a subject, incoming / outgoing calls, transmission / reception of an e-mail, etc.) according to an operation instruction output from the operation input unit 12 and input.

  The operation input unit 12 may include a touch panel provided integrally with the display unit 8, and an operation instruction corresponding to the predetermined operation is given to the central control unit based on a predetermined operation of the touch panel by the user. 1 may be output.

<Code reading process>
Next, a code reading process performed by the mobile terminal 100 will be described with reference to FIGS.
FIG. 2 is a flowchart illustrating an example of an operation related to the code reading process.
It is assumed that the imprint Si imaged in the following code reading process is stamped at a predetermined position of the recording medium P such as a postcard (see FIG. 3A). Further, it is assumed that the same code information Sc is added to each side Sa of the frame portion Sw of the seal imprint Si.

As shown in FIG. 2, first, when an imaging instruction is input based on a predetermined operation of the operation input unit 12 by the user, the imaging control unit 4 causes the imaging unit 3 to image the imprint Si, and the image data generation unit 5. Generates image data of the captured image Ia transferred from the electronic imaging unit 3b (step S1; see FIG. 3B).
Then, the image data generation unit 5 outputs the generated YUV data of the captured image Ia to the memory 2 and stores it in the memory 2.

  Note that the display control unit 9 may cause the display unit 8 to display a guide display corresponding to the outer shape of the imprint Si in order to make it easier to capture the imprint Si in a state closer to a square.

  Next, the image acquisition unit 6a of the code processing unit 6 acquires image data (for example, luminance data) of a predetermined resolution of the captured image Ia generated by the image data generation unit 5 from the memory 2 (step S2; FIG. 4 (a)). Subsequently, the binarization unit 6b performs binarization processing that binarizes the image data of the captured image Ia acquired by the image acquisition unit 6a with a predetermined threshold value, so that the first binarized image is obtained. Image data of Ib (see FIG. 4B) is generated (step S3).

  Next, the contour specifying unit c1 of the straight line estimation unit 6c performs a convex hull process on the image data of the first binarized image Ib generated by the binarization unit 6b, thereby the outer contour of the frame portion Sw. A polygonal convex hull region A1 (see FIG. 4C) corresponding to is specified (step S4). Specifically, the contour specifying unit c1 uses the convex hull region A having the largest area among the plurality of convex hull regions A formed by the convex hull processing as the outer contour of the frame portion Sw of the imprint Si. A corresponding polygonal (for example, hexagonal) convex hull region A1 is specified.

  Subsequently, the straight line specifying unit c2 includes a polygonal convex hull among a plurality of straight lines L passing through any two vertices B constituting the polygonal convex hull region A1 specified by the contour specifying unit c1. A straight line L in which the number of overlapping pixels constituting the region A1 is greater than a predetermined value is specified as a straight line L that forms the outer contour of the frame image Wa corresponding to the frame portion Sw (step S5). Specifically, the straight line specifying unit c2 selects any two vertices B, B from the six vertices B constituting the convex hull region A1, and connects these two vertices B, B. This straight line L is specified as a candidate straight line L constituting the square outer contour of the frame image Wa. Then, the straight line specifying unit c2 selects the candidate straight line L having the number of pixels overlapping with a plurality of pixels constituting the convex hull region A1 in the specified candidate straight line L as the outer contour of the frame image Wa. Is specified as a straight line L constituting.

  Next, the straight line specifying unit c2 considers an angle formed with an adjacent straight line L among a plurality of straight lines L passing through any two vertices B, B constituting the convex hull region A1 having a polygonal shape. The straight line L constituting the outer contour of the frame image Wa is specified (step S6). Specifically, the straight line specifying unit c2 specifies a candidate straight line L for which all the candidate straight lines L are substantially equal to the interior angle (90 °) of the square frame of the seal S with respect to the adjacent candidate straight line L. Then, an evaluation value for each candidate straight line L is calculated according to a predetermined arithmetic expression by weighting pixels overlapping the polygonal convex hull region A1. The straight line specifying unit c2 compares the calculated evaluation values of the candidate straight lines L, and specifies the candidate straight line L having the highest evaluation value as the straight line L constituting the outer contour of the frame image Wa.

  Note that the order of the process of specifying the straight line L in step S5 and the process of specifying the straight line L in step S6 is merely an example, and is not limited to this. For example, the order may be reversed.

Then, the vertex specifying unit d1 of the frame detecting unit 6d uses a predetermined number of points where the predetermined number of straight lines L constituting the outer contour specified by the straight line specifying unit c2 intersect, and the frame portion Sw of the imprint Si (frame image Wa). Is specified as a vertex C (step S7). At this time, the vertex specifying unit d1 may specify the vertex C of the frame image Wa in consideration of the coordinate position of the marker image Ma in the captured image Ia (see FIGS. 7A to 7C). ).
Subsequently, the frame detection unit 6d determines whether or not four vertices C of the frame image Wa have been identified based on the identification result by the vertex identification unit d1 (step S8). If it is determined that four vertices C of the frame image Wa have been identified (step S8; YES), the projective transformation unit d2 takes a captured image with reference to the coordinate positions of the identified four vertices C,. Projective transformation processing is performed on Ia (step S9). Specifically, the projective transformation unit d2 performs coordinate transformation such that the coordinate positions of the four vertices C,... Of the rectangular frame image Wa having a distorted outer shape become the coordinate positions of the four vertices C,. According to the calculated coordinate conversion formula, a projection conversion process is performed on the captured image Ia of the imprint Si, and a projection-converted image Ic obtained by converting the outline of the frame image Wa of the imprint Si into a square shape is obtained. Generate.

  If it is determined in step S8 that four vertices C of the frame image Wa have not been specified (step S8; NO), the CPU of the central control unit 1 skips the subsequent processing and performs the code The reading process is terminated.

  Next, the frame detection unit 6d detects a square frame portion Sw (frame image Wa) corresponding to the frame of the seal S in the projective transformed image Ic generated by the projective transformation unit d2 (step S10). . Subsequently, the binarization unit 6b performs binarization processing that binarizes the image data of the projection-converted image Ic generated by the projection conversion unit d2 with a predetermined threshold value, thereby obtaining a second binary value. Image data of the digitized image Id is generated (step S11).

  Next, the information reading unit 6e obtains predetermined information from the code information Sc in the frame portion Sw (frame image Wa) of the second binarized image Id corresponding to the projection-converted image Ic generated by the projection conversion unit d2. Is read (step S12). Specifically, the information reading unit 6e identifies a square-shaped reading area D in the second binarized image Id, and follows a predetermined direction from a predetermined position (for example, the upper left corner) of the reading area D. Scanning, the coordinate positions where the set of white pixels having the pixel value “1” and the set of black pixels having the pixel value “0” exist are respectively specified. Then, the information reading unit 6e performs a decoding process on the specified array of white pixels and black pixels to obtain the original predetermined information (for example, URL) represented by the code information Sc. read.

Subsequently, the information reading unit 6e determines whether or not the original predetermined information is read a plurality of times from the code information Sc by the reading process (step S13).
Here, when it is determined that the original predetermined information has been read a plurality of times (step S13; YES), the information reading unit 6e determines that the predetermined information has been properly read, and the operation processing unit 7 Performs a predetermined operation (for example, reproduction of a specific sound or image by accessing the Internet, for example) according to predetermined information (for example, URL) read by the information reading unit 6e (step S14).

  On the other hand, if it is determined in step S13 that the original predetermined information has not been read a plurality of times (step S13; NO), the CPU of the central control unit 1 skips the process of step S14 and executes the code The reading process is terminated.

  As described above, according to the mobile terminal 100 of the present embodiment, the imprint Si obtained by adding the code information Sc to the polygonal (for example, square) frame portion Sw around the predetermined stamp image Sp is imaged. In the captured image Ia, an outer contour of the frame portion Sw (frame image Wa) corresponding to the polygonal frame of the seal S is formed, and a predetermined number of straight lines L corresponding to the number of corners of the polygonal frame are estimated. Since the frame image Wa of the captured image Ia composed of the estimated predetermined number of straight lines L is detected, the frame image of the captured image Ia is used by using the predetermined number of straight lines L that form the outer contour of the frame image Wa. Wa can be detected appropriately. That is, for example, even if the imprint Si is blurred or blurred and the vertex C of the frame image Wa cannot be detected properly, a predetermined number of straight lines L that form the outer contour of the frame image Wa. By using the straight line L, it is possible to appropriately detect the frame portion Sw (frame image Wa) from the captured image Ia.

Further, a polygonal region (convex hull region A1) corresponding to the outer contour of the frame portion Sw (frame image Wa) of the captured image Ia is specified, and a plurality of vertices B constituting the specified polygonal region,. Since the predetermined number of straight lines L constituting the outer contour of the frame image Wa is specified based on the position of the frame image Wa, the detection of the frame image Wa from the captured image Ia is appropriately performed using the specified predetermined number of straight lines L. It can be carried out. Specifically, among the plurality of straight lines L passing through any two vertices B constituting the polygonal area, the number of pixels in which each straight line L and the polygonal area overlap and adjacent straight lines Based on at least one of the relative relationships between L, a predetermined number of straight lines L constituting the outer contour of the frame image Wa can be specified.
That is, among a plurality of straight lines L that pass through any two vertices B, which constitute a polygonal region, a straight line L in which the number of overlapping pixels constituting the polygonal region is greater than a predetermined value. And the straight line L is specified as the straight line L constituting the outer contour of the frame image Wa, so that the candidate straight line L of the straight line L constituting the outer contour of the frame image Wa and a plurality of pixels constituting the polygonal region The straight line L that constitutes the outer contour of the frame image Wa can be properly specified.
Further, among the plurality of straight lines L passing through any two vertices B, B constituting the polygonal region, a straight line L whose angle formed with the adjacent straight line L is substantially equal to the inner angle of the polygonal frame Identify and calculate an evaluation value for each straight line L by weighting pixels overlapping the polygonal region among the pixels constituting the straight line L, and calculate the straight line L having a high calculated evaluation value of the frame image Wa. Since it is specified as the straight line L constituting the outer contour, the relative relationship between the candidate straight lines L of the straight line L constituting the outer contour of the frame image Wa is considered, and the straight line L constituting the outer contour of the frame image Wa is considered. Identification can be performed appropriately.

Further, a predetermined number of points where a predetermined number of straight lines L that form the outer contour of the frame portion Sw (frame image Wa) intersect are specified as vertices C of the frame image Wa, and based on the specified predetermined number of vertices C Since the frame image Wa of the captured image Ia is detected, the frame image Wa of the captured image Ia is detected using a predetermined number of points (vertices C) at which a predetermined number of straight lines L forming the outer contour of the frame image Wa intersect. Detection can be performed properly. At this time, by specifying the vertex C of the frame image Wa based on the coordinate position of the marker image Ma corresponding to the marker Sm having a predetermined shape at the corner of the polygonal frame in the captured image Ia, for example, Even in the picked-up image Ia obtained by picking up the imprinted seal Si, the vertex C of the frame image Wa can be specified appropriately, and the frame image Wa of the picked-up image Ia can be detected properly.
Further, based on the specified predetermined number of vertices C, projective transformation processing is performed on the captured image Ia to generate a polygonal captured image (projection-converted image Ic), and the generated polygonal captured image Since the frame image Wa corresponding to the frame of Ia is detected, a predetermined number of straight lines L constituting the outer contour of the frame image Wa intersect even in the captured image Ia obtained by capturing the imprint Si in which blur or blur has occurred. The projective transformation process can be appropriately performed using a predetermined number of points (vertex C), and as a result, the polygonal frame image Wa can be properly detected.

  Further, it is possible to appropriately read predetermined information from the code information Sc in the frame portion Sw (frame image Wa) of the captured image Ia. At this time, when a predetermined number or more of predetermined information is read from the captured image Ia of the imprint Si in which a plurality of the same code information Sc is added to the frame portion Sw, execution of a process corresponding to the predetermined information is controlled. Therefore, by embedding a plurality of code information Sc,... In the frame portion Sw in a multiple manner, the original predetermined information can be stably read from the code information Sc and corresponds to the read predetermined information. Processing can be executed properly.

The present invention is not limited to the above-described embodiment, and various improvements and design changes may be made without departing from the spirit of the present invention.
Below, the modification of the portable terminal 100 is demonstrated.

<Modification 1>
FIG. 8 is a block diagram illustrating a schematic configuration of the mobile terminal 200 according to the first modification.
As shown in FIG. 8, the code processing unit 206 of the mobile terminal 200 according to the first modification includes an image acquisition unit 6a, a binarization unit 6b, a straight line estimation unit 6c, a frame detection unit 6d, and an information reading unit 6e. The pixel number reduction unit 6f is provided.
Note that the configuration of the mobile terminal 200 of Modification 1 is substantially the same as the mobile terminal 100 of the above-described embodiment except for the details described below, and detailed description thereof is omitted.

The pixel number reduction unit 6f performs a pixel number reduction process for reducing the number of pixels existing in the background of the captured image Ia.
That is, the pixel number reduction unit (pixel number reduction unit) 6f relatively sets the number of pixels existing in the background to the first binarized image Ib corresponding to the captured image Ia acquired by the image acquisition unit 6a. Process to reduce. Specifically, when the imprint Si is not a recording medium having a uniform color or pattern, for example, when the stamp Si is stamped on the ruled line N of the notebook (see FIG. 10A), the frame by the straight line estimation unit 6c is used. There is a possibility that the straight line L constituting the outer contour of the part Sw (frame image Wa) cannot be estimated properly.
Therefore, the pixel number reduction unit 6f acquires the image data of the first binarized image Ib generated by the binarization unit 6b, and performs a process of inverting the white pixel and the black pixel (FIG. 10 ( b)), and an expansion process and a contraction process for removing a pixel set smaller than a predetermined value existing in the background of the first binarized image Ib are performed (see FIG. 10C, etc.). For example, the pixel number reduction unit 6f performs an expansion process for adding pixels around each pixel to be processed in the black and white inverted image Ie (see FIG. 10B) of the first binarized image Ib. After (see FIG. 10C), a contraction process for stripping the pixel around the lid is performed (see FIG. 11A), and then an expansion process for adding the pixel around is performed (see FIG. 11B). Thereby, the number of pixels existing in the background in the first binarized image Ib is reduced relative to the number of pixels constituting the frame image Wa, and the straight line estimation unit 6c defines the outer contour of the frame image Wa. When the straight line L to be constructed is estimated, the influence of pixels existing in the background of the imprint Si is reduced.

  The straight line estimation unit 6c configures the outer contour of the frame portion Sw (frame image Wa) corresponding to the square frame of the seal S in the first binarized image Ib after processing by the pixel number reduction unit 6f. After estimating the four straight lines L,..., The frame detector 6d detects the frame image Wa of the captured image Ia (see FIG. 11C).

<Code reading process>
Next, a code reading process in the mobile terminal 200 of the first modification will be described with reference to FIG.
FIG. 9 is a flowchart illustrating an example of an operation related to the code reading process.
The code reading process performed by the mobile terminal 200 according to the first modification is substantially the same as the code reading process performed by the mobile terminal 100 according to the above-described embodiment except for the details described below, and detailed description thereof is omitted.

As shown in FIG. 9, the code processing unit 206 performs the processes of steps S1 to S3 in the same manner as the code reading process by the mobile terminal 100 of the above-described embodiment, and performs the first binarized image Ib (FIG. 4 ( b)) is generated.
The pixel number reduction unit 6f performs pixel number reduction processing on the generated image data of the first binarized image Ib (step S21). Specifically, the pixel number reduction unit 6f performs a process of inverting the white pixel and the black pixel on the image data of the first binarized image Ib, and then performs an expansion process and a contraction process to perform the first process. The number of pixels existing in the background in the binarized image Ib is reduced relative to the number of pixels constituting the frame portion Sw (frame image Wa).

Subsequently, the contour specifying unit c1 performs a convex hull process on the image data of the first binarized image Ib after the pixel number reduction process, thereby forming a polygonal convex hull corresponding to the outer contour of the frame portion Sw. An area A1 (see FIG. 4C) is specified (step S4).
Then, the code processing unit 206 performs each process after step S4 in the same manner as the code reading process by the mobile terminal 100 of the above-described embodiment, so that the straight line L that forms the outer contour of the frame portion Sw (frame image Wa). Detection (steps S5 and S6), detection of the frame portion Sw (frame image Wa) (step S10), reading of predetermined information from the code information (step S12), and the like are performed.

  Therefore, according to the mobile terminal 200 of the first modification, a process of relatively reducing the number of pixels existing in the background of the captured image Ia is performed, and the frame portion Sw (frame image) is included in the captured image Ia after the process. Since a predetermined number of straight lines L constituting the outer contour of Wa) are estimated, even if the imprint Si is not a recording medium having a uniform color or pattern, for example, it is stamped on a notebook having a ruled line N By reducing the number of pixels existing in the background of the captured image Ia relatively, the influence of the pixels existing in the background of the captured image Ia is reduced, and the estimation of the straight line L constituting the outer contour of the frame image Wa is appropriate. Can be done.

  Moreover, in the said embodiment, the straight line specific | specification part c2 is each straight line L and a polygonal shape in the some straight line L which passes along any two vertex B, B which comprises polygonal convex hull area | region A1, ... The predetermined number of straight lines L constituting the outer contour of the frame image Wa is specified based on both the number of pixels overlapping the convex hull region A1 and the relative relationship between the adjacent straight lines L. Only one of them may be used as a reference.

  Furthermore, in the said embodiment, although the shape of the frame part Sw was made into square shape, it is an example and is not restricted to this, For example, polygonal shapes other than a square may be sufficient.

  In the above embodiment, the same code information Sc is added to each side Sa of the frame portion Sw of the seal imprint Si. However, this is an example, and the present invention is not limited thereto. Information Sc may be added. In this case, the amount of code information (original predetermined information) Sc embedded in the frame portion Sw can be increased.

  Furthermore, in the above-described embodiment, the portable terminals 100 and 200 are illustrated as the image processing apparatuses. However, the image processing apparatus is an example and is not limited thereto, and the execution of the detection process of the frame portion Sw (frame image Wa) can be controlled. Any change can be made as appropriate.

In addition, in the above embodiment, the functions of the acquisition unit, the estimation unit, and the detection unit are controlled by the central control unit 1 of the mobile terminal 100 (200), and the image acquisition unit 6a and the straight line estimation unit 6c. However, the present invention is not limited to this, and may be realized by a predetermined program executed by the CPU of the central control unit 1. .
That is, a program including an acquisition process routine, an estimation process routine, and a detection process routine is stored in a program memory that stores the program. Then, the CPU of the central control unit 1 may function as a means for acquiring a captured image Ia obtained by capturing an imprint in which the code information Sc is added to the polygonal frame portion Sw. Further, the CPU of the central control unit 1 configures the outer contour of the frame portion Sw in the acquired captured image Ia by the estimation processing routine, and a predetermined number of straight lines corresponding to the number of corners of the polygonal frame of the seal S You may make it function as a means to estimate L. Further, the CPU of the central control unit 1 may function as a means for detecting the frame portion Sw of the captured image Ia constituted by the estimated predetermined number of straight lines L by the detection processing routine.

  Similarly, a predetermined program or the like is executed by the CPU of the central control unit 1 for the first specifying means, the second specifying means, the third specifying means, the generating means, the reading means, the processing means, and the pixel number reducing means. It is good also as a structure implement | achieved by.

  Furthermore, as a computer-readable medium storing a program for executing each of the above processes, a non-volatile memory such as a flash memory or a portable recording medium such as a CD-ROM is applied in addition to a ROM or a hard disk. Is also possible. A carrier wave is also used as a medium for providing program data via a predetermined communication line.

[Appendix]
Although several embodiments of the present invention have been described, the scope of the present invention is not limited to the above-described embodiments, but includes the scope of the invention described in the claims and equivalents thereof.
The invention described in the scope of claims attached to the application of this application will be added below. The item numbers of the claims described in the appendix are as set forth in the claims attached to the application of this application.
<Claim 1>
An acquisition means for acquiring an imprint image obtained by capturing an imprint in which code information is added to a polygonal frame portion;
An estimation unit that configures an outer contour of the frame portion and estimates a predetermined number of straight lines according to the number of corners of the polygonal frame in the imprint image acquired by the acquisition unit;
Detecting means for detecting the frame portion of the imprint image composed of a predetermined number of straight lines estimated by the estimating means;
An image processing apparatus comprising:
<Claim 2>
The estimation means includes
First specifying means for specifying a polygonal region corresponding to the outer contour of the frame portion of the imprint image acquired by the acquiring means;
Second specifying means for specifying a predetermined number of straight lines constituting the outer contour of the frame portion based on the positions of a plurality of vertices constituting the polygonal area specified by the first specifying means; The image processing apparatus according to claim 1.
<Claim 3>
The second specifying means further includes:
Among a plurality of straight lines passing through any two vertices constituting the polygonal area specified by the first specifying means, the number of pixels in which each straight line and the polygonal area overlap each other and adjacent straight lines The image processing apparatus according to claim 1, wherein a predetermined number of straight lines constituting the outer contour of the frame portion are specified based on at least one of the relative relationships.
<Claim 4>
The second specifying means further includes:
Among a plurality of straight lines passing through any two vertices constituting the polygonal area specified by the first specifying means, the number of overlapping pixels constituting the polygonal area is greater than a predetermined value. The image processing apparatus according to claim 3, wherein a straight line is specified, and the straight line is specified as a straight line constituting an outer contour of the frame portion.
<Claim 5>
The second specifying means further includes:
Among a plurality of straight lines that pass through any two vertices constituting the polygonal area specified by the first specifying means, a straight line having an angle that is substantially equal to an internal angle of the polygonal frame is formed. Identify and calculate an evaluation value for each straight line by weighting pixels overlapping the polygonal region among the pixels constituting the straight line, and calculate a straight line with a high evaluation value to the outer contour of the frame part 5. The image processing apparatus according to claim 3, wherein the image processing apparatus is specified as a straight line that constitutes a line.
<Claim 6>
The detection means includes
A third specifying means for specifying a predetermined number of points where the predetermined number of straight lines specified by the second specifying means intersect as vertexes of the frame portion;
The image processing apparatus according to claim 2, wherein the frame portion of the imprint image is detected based on a predetermined number of vertices specified by the third specifying unit.
<Claim 7>
The seal is formed by molding a marker of a predetermined shape at a corner of the polygonal frame,
The third specifying means further includes:
The position of the marker image corresponding to the marker is specified in the imprint image acquired by the acquisition means, and the vertex of the frame portion is specified based on the specified position of the marker image. Item 7. The image processing apparatus according to Item 6.
<Claim 8>
The detection means includes
Based on a predetermined number of vertices specified by the third specifying means, further comprising a generating means for performing a projective transformation process on the imprint image acquired by the acquiring means to generate a polygonal imprint image,
The image processing apparatus according to claim 7, wherein a frame portion corresponding to a frame of the polygonal imprint image generated by the generation unit is detected.
<Claim 9>
The image processing according to claim 1, further comprising a reading unit that reads predetermined information from the code information in the frame portion of the imprint image detected by the detection unit. apparatus.
<Claim 10>
A plurality of the code information is added to the polygonal frame portion of the imprint,
The image processing apparatus according to claim 9, further comprising a processing unit that controls execution of a process corresponding to the predetermined information when the predetermined number of the predetermined information is read by the reading unit. .
<Claim 11>
Further comprising pixel number reduction means for performing a process of relatively reducing the number of pixels existing in the background of the imprint image with respect to the imprint image acquired by the acquisition means,
The estimation means includes
The image processing apparatus according to claim 1, wherein the predetermined number of straight lines are estimated in an imprint image processed by the pixel number reducing unit.
<Claim 12>
An image processing method using an image processing apparatus,
A process of acquiring an imprint image obtained by capturing an imprint in which code information is added to a polygonal frame portion;
In the acquired imprint image, the outer contour of the frame part is configured, and a process of estimating a predetermined number of straight lines according to the number of corners of the polygonal frame;
A process of detecting the frame portion of the imprint image composed of an estimated predetermined number of straight lines;
An image processing method comprising:
<Claim 13>
The computer of the image processing device
An acquisition means for acquiring an imprint image obtained by capturing an imprint in which code information is added to a polygonal frame portion;
An estimation unit that configures an outer contour of the frame portion and estimates a predetermined number of straight lines according to the number of corners of the polygonal frame in the imprint image acquired by the acquisition unit;
Detecting means for detecting the frame portion of the imprint image constituted by a predetermined number of straight lines estimated by the estimating means;
A program characterized by functioning as

100, 200 Mobile terminal 1 Central control unit 6, 206 Code processing unit 6a Image acquisition unit 6c Line estimation unit c1 Outline identification unit c2 Line identification unit 6d Frame detection unit d1 Vertex identification unit d2 Projection conversion unit 6e Information reading unit 6f Number of pixels Reduction unit 7 Operation processing unit

Claims (13)

An acquisition means for acquiring an imprint image obtained by capturing an imprint in which code information is added to a polygonal frame portion;
An estimation unit that configures an outer contour of the frame portion and estimates a predetermined number of straight lines according to the number of corners of the polygonal frame in the imprint image acquired by the acquisition unit;
Detecting means for detecting the frame portion of the imprint image composed of a predetermined number of straight lines estimated by the estimating means;
An image processing apparatus comprising: The estimation means includes
First specifying means for specifying a polygonal region corresponding to the outer contour of the frame portion of the imprint image acquired by the acquiring means;
Second specifying means for specifying a predetermined number of straight lines constituting the outer contour of the frame portion based on the positions of a plurality of vertices constituting the polygonal area specified by the first specifying means; The image processing apparatus according to claim 1. The second specifying means further includes:
Among a plurality of straight lines passing through any two vertices constituting the polygonal area specified by the first specifying means, the number of pixels in which each straight line and the polygonal area overlap each other and adjacent straight lines The image processing apparatus according to claim 2 , wherein a predetermined number of straight lines constituting the outer contour of the frame portion are specified based on at least one of the relative relationships. The second specifying means further includes:
Among a plurality of straight lines passing through any two vertices constituting the polygonal area specified by the first specifying means, the number of overlapping pixels constituting the polygonal area is greater than a predetermined value. The image processing apparatus according to claim 3, wherein a straight line is specified, and the straight line is specified as a straight line constituting an outer contour of the frame portion. The second specifying means further includes:
Among a plurality of straight lines that pass through any two vertices constituting the polygonal area specified by the first specifying means, a straight line having an angle that is substantially equal to an internal angle of the polygonal frame is formed. Identify and calculate an evaluation value for each straight line by weighting pixels overlapping the polygonal region among the pixels constituting the straight line, and calculate a straight line with a high evaluation value to the outer contour of the frame part 5. The image processing apparatus according to claim 3, wherein the image processing apparatus is specified as a straight line that constitutes a line. The detection means includes
A third specifying means for specifying a predetermined number of points where the predetermined number of straight lines specified by the second specifying means intersect as vertexes of the frame portion;
The image processing apparatus according to claim 2, wherein the frame portion of the imprint image is detected based on a predetermined number of vertices specified by the third specifying unit. The seal is formed by molding a marker of a predetermined shape at a corner of the polygonal frame,
The third specifying means further includes:
The position of the marker image corresponding to the marker is specified in the imprint image acquired by the acquisition means, and the vertex of the frame portion is specified based on the specified position of the marker image. Item 7. The image processing apparatus according to Item 6. The detection means includes
Based on a predetermined number of vertices specified by the third specifying means, further comprising a generating means for performing a projective transformation process on the imprint image acquired by the acquiring means to generate a polygonal imprint image,
The image processing apparatus according to claim 7, wherein a frame portion corresponding to a frame of the polygonal imprint image generated by the generation unit is detected.   The image processing according to claim 1, further comprising a reading unit that reads predetermined information from the code information in the frame portion of the imprint image detected by the detection unit. apparatus. A plurality of the code information is added to the polygonal frame portion of the imprint,
The image processing apparatus according to claim 9, further comprising a processing unit that controls execution of a process corresponding to the predetermined information when the predetermined number of the predetermined information is read by the reading unit. . Further comprising pixel number reduction means for performing a process of relatively reducing the number of pixels existing in the background of the imprint image with respect to the imprint image acquired by the acquisition means,
The estimation means includes
The image processing apparatus according to claim 1, wherein the predetermined number of straight lines are estimated in an imprint image processed by the pixel number reducing unit. An image processing method using an image processing apparatus,
A process of acquiring an imprint image obtained by capturing an imprint in which code information is added to a polygonal frame portion;
In the acquired imprint image, the outer contour of the frame part is configured, and a process of estimating a predetermined number of straight lines according to the number of corners of the polygonal frame;
A process of detecting the frame portion of the imprint image composed of an estimated predetermined number of straight lines;
An image processing method comprising: The computer of the image processing device
An acquisition means for acquiring an imprint image obtained by capturing an imprint in which code information is added to a polygonal frame portion;
An estimation unit that configures an outer contour of the frame portion and estimates a predetermined number of straight lines according to the number of corners of the polygonal frame in the imprint image acquired by the acquisition unit;
Detecting means for detecting the frame portion of the imprint image constituted by a predetermined number of straight lines estimated by the estimating means;
A program characterized by functioning as

Images