JP2013131057A - Two-dimensional code, recording device, device and program for identification - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a two-dimensional code, a recording device, a device and a program for identification that contribute highly-accurate interpretation of information to be interpreted.SOLUTION: A two-dimensional code 30 includes: patterns to be read having an interpretation supporting binary pattern 32 and an interpretation supporting binary pattern 34; and a standard binary pattern 36 that is inserted in a specific position of the pattern to be read to be represented in accordance with the presence of a specific color, and is a standard for identifying the presence of the specific color of pixels included in at least one of the interpretation supporting binary pattern 32 and the interpretation supporting binary pattern 34.

Description

  The present invention relates to a two-dimensional code, a recording device, an identification device, and a program.

  Patent Document 1 discloses a technique for accurately binarizing an image having an uneven brightness distribution. This technique realizes binarization processing using a threshold value derived from a histogram obtained based on image information.

  Patent Document 2 also discloses a technique for accurately binarizing an image having an uneven brightness distribution. This technique includes threshold setting means for setting a threshold for each part of image data.

Japanese Patent Laid-Open No. 03-237571 Japanese Patent Application Laid-Open No. 07-085245

  An object of the present invention is to provide a two-dimensional code, a recording device, an identification device, and a program that contribute to highly accurate decoding of information to be decoded.

  In order to solve the above-described problem, the two-dimensional code according to claim 1 is recorded in a specific area in the recording target area, and support information for supporting the decoding of the decoding target information is determined based on the presence or absence of specific colors of a plurality of pixels. A decoded decoding support binary design, and a decoding target binary design recorded in an area other than the specific area in the recording target area and the decoding target information expressed by the presence or absence of the specific color of a plurality of pixels. The reading target symbol, and the identification of pixels included in at least one of the decoding support binary symbol and the decoding target binary symbol, which is inserted at a specific position of the reading target symbol and expressed by the presence or absence of the specific color Reference information used as a reference for identifying the presence / absence of a color includes a reference binary pattern expressed by the presence / absence of a specific color of a plurality of pixels.

  In order to solve the above-mentioned problem, the two-dimensional code according to claim 2 is recorded in a specific area in the recording target area, and support information for supporting the decoding of the decoding target information is determined based on the presence or absence of a specific color of a plurality of pixels. A decoded decoding support binary design, and a decoding target binary design recorded in an area other than the specific area in the recording target area and the decoding target information expressed by the presence or absence of the specific color of a plurality of pixels. A reading target symbol, and a pixel included in at least one of the decoding support binary symbol and the decoding target binary symbol that is inserted at a specific position of the reading target symbol and is represented by the presence or absence of the specific color. The reference information used as a reference for identifying the presence / absence of the specific color includes a plurality of reference binary patterns expressed by the presence / absence of the specific color of the plurality of pixels.

  The recording target area including the two-dimensional code according to claim 2 and the reference binary symbol including the decoding assist binary symbol and the decoding target binary symbol as in the invention according to claim 3 Was inserted into each of the divided regions obtained by dividing the.

  A plurality of two-dimensional codes according to claim 2 inserted into each of the divided areas obtained by dividing the design to be read, as in the invention according to claim 4, did.

  The two-dimensional code according to claim 3 or claim 4, wherein, as in the invention according to claim 5, the divided region is a region obtained by dividing the pattern to be read into a matrix. did.

  The two-dimensional code according to any one of claims 2 to 5 is converted into a reference position in the read target symbol and each of the reference binary symbols as in the invention according to claim 6. The positional relationship was assumed to be a predetermined positional relationship for each reference binary symbol.

  The two-dimensional code according to any one of claims 2 to 6 is arranged such that the plurality of reference binary symbols have predetermined intervals as in the invention according to claim 7. It was inserted into the reading object design.

  In the two-dimensional code according to any one of claims 1 to 7, the specific color is an achromatic color as in the invention according to claim 8.

  In the two-dimensional code according to any one of claims 1 to 7, the specific color is a chromatic color as in the invention according to claim 8.

  The two-dimensional code according to any one of claims 1 to 9, and the reference binary pattern as in the invention according to claim 10, wherein a color of one of the pixels is the specific color. A different pair of pixels was used.

  The two-dimensional code according to any one of claims 1 to 9, and the decoding support binary symbol and the decoding target binary symbol as a pair of nulls, as in the invention according to claim 11. And forming the other with a pair of chromatic colors, and forming the reference binary symbol as a pair of achromatic colors and included in one of the decoding support binary symbol and the decoding target binary symbol A first reference symbol as a reference for identifying the presence or absence, and a criterion for identifying the presence or absence of a pixel formed of a pair of chromatic colors and included in the other of the decoding support binary symbol and the decoding target binary symbol The second reference symbol is assumed to be included.

  The two-dimensional code according to claim 11 is different from the first reference symbol and the second reference symbol in which the specific color is used for each of the first reference symbol and the second reference symbol as in the invention according to claim 12. A pair of pixels was used.

  The two-dimensional code according to any one of claims 1 to 12, wherein the recording target area is a quadrangular shape as in the invention according to claim 13, and the decoding support binary symbol is Position identification information that is recorded in at least three of the four corners of the recording target area and that supports the specification of the positions of the pixels included in the recording target area is expressed by the presence or absence of specific colors of a plurality of pixels It was assumed that it included the support binary design.

  The two-dimensional code according to claim 13, the position specifying support binary symbol as in the invention according to claim 14, the set of a plurality of adjacent pixels having the specific color and the specific color. It was formed by combining a set of a plurality of pixels adjacent to each other.

  The two-dimensional code according to claim 13 or 14 is inserted at a predetermined position of the recording target area along at least one side of the recording target area as in the invention of claim 15. Support assisting binary information represented by presence / absence of the specific color of a plurality of pixels, wherein support assisting information assisting the specific support of the positions of the pixels included in the read target symbol by the position specifying assisting binary design. Further included.

  The two-dimensional code according to claim 13 or 14, respectively, at a predetermined position of the recording target area along at least one side of the recording target area, as in the invention of claim 16. A plurality of support assists, each of which is represented by the presence / absence of the specific color of a plurality of pixels, wherein support assist information for assisting the specific support of the positions of the pixels included in the symbol to be read by the position specifying support binary symbol A binary pattern was further included.

  A plurality of the two-dimensional codes according to claim 16 inserted into the recording target area in units of one side of the recording target area, as in the invention according to claim 17, did.

  The two-dimensional code according to claim 17, the plurality of support auxiliary binary symbols, as in the invention according to claim 18, including the position specifying support binary symbols in one side unit of the recording target area. And arranged so that the distance between them is uniform.

  The two-dimensional code according to any one of claims 16 to 18, the support auxiliary binary symbol as in the invention according to claim 19, and at least one pair of opposite sides of the recording target area. It was assumed that it was inserted into the recording target area along each side.

  The two-dimensional code according to claim 19, as in the invention according to claim 20, wherein each of the support auxiliary binary symbols inserted into the recording target area along each side of the set of opposite sides. The information corresponding to the support auxiliary information inserted into the recording target area on the line segment connecting the two lines further includes another support auxiliary binary pattern expressed by the presence or absence of the specific color of a plurality of pixels. .

  In order to solve the above problem, the recording apparatus according to claim 21 includes a recording unit that records the two-dimensional code according to any one of claims 1 to 20 on a recording medium.

  In order to solve the above-mentioned problem, the identification device according to claim 22 is configured such that the decoding support binary symbol and the decoding target binary symbol in the two-dimensional code according to any one of claims 1 to 20. The pixel included in at least one of the pixels is set as a pixel to be identified, and based on the reading result obtained by reading the two-dimensional code with a reading device, the pixel information to be identified indicating the pixel to be identified and the reference binary indicating the reference binary pattern Acquisition means for acquiring value symbol information; and based on the reference binary symbol information acquired by the acquisition means, the specific color of the identification target pixel indicated by the identification target pixel information acquired by the acquisition means And identification means for identifying the presence or absence.

  The identification device according to claim 22 is a pixel included in at least one of the decoding support binary symbol and the decoding target binary symbol as in the invention according to claim 23, wherein the reference binary symbol is included. The pixels within a predetermined distance are the identification target pixels.

  In the identification device according to claim 22 or claim 23, as in the invention according to claim 24, when the acquisition unit uses the pixel included in the binary pattern to be decoded as the identification target pixel, From the read result, the decoding support binary symbol information indicating the decoding support binary symbol is further acquired, and the identification unit includes the reference binary symbol information and the decoding support binary symbol information acquired by the acquisition unit. Based on this, the presence / absence of the specific color of the identification target pixel indicated by the identification target pixel information acquired by the acquisition unit is identified.

  In order to solve the above-described problem, the program according to claim 25 is executed by adding the decoding support binary symbol and the decoding target binary symbol in the two-dimensional code according to any one of claims 1 to 20. A pixel included in at least one is set as a pixel to be identified, and based on a reading result obtained by reading the two-dimensional code with a reading device, identification target pixel information indicating the identification target pixel and a reference binary indicating the reference binary pattern An acquisition unit for acquiring symbol information, and the specific color of the identification target pixel indicated by the identification target pixel information acquired by the acquisition unit based on the reference binary symbol information acquired by the acquisition unit. The computer is made to function as an identification means for identifying presence or absence.

  According to the inventions according to claim 1, claim 2, claim 21, claim 22 and claim 25, the two-dimensional code is inserted at a specific position of the pattern to be read and expressed by the presence or absence of a specific color. A reference binary design in which reference information for identifying the presence or absence of a specific color of a pixel included in at least one of a decoding support binary design and a decoding target binary design is expressed by the presence or absence of a specific color of a plurality of pixels As compared with the case where the configuration including the number is not included, an effect of contributing to highly accurate decoding of the information to be decoded can be obtained.

  According to the invention according to claim 3, a configuration in which the reference binary symbol is inserted into each of the divided regions obtained by dividing the recording target region including the decoding support binary symbol and the decoding target binary symbol. Compared with the case where it does not have, the effect that it contributes to the highly accurate discrimination | determination of the presence or absence of the specific color of the pixel contained in at least one of a decoding assistance binary symbol and a decoding object binary symbol is acquired.

  According to the invention of claim 4, compared to the case where there is no configuration in which a plurality of reference binary symbols are inserted in each of the divided areas obtained by dividing the read target symbol, the decoding support binary symbol and the decoding target An effect of contributing to highly accurate identification of the presence or absence of a specific color of pixels included in at least one of the binary symbols is obtained.

  According to the fifth aspect of the present invention, compared to a case where the divided area does not have a configuration obtained by dividing the pattern to be read in a matrix shape, the process for identifying the presence or absence of a specific color of the pixel is involved. The effect that it contributes to reduction of load is acquired.

  According to the sixth aspect of the present invention, the positional relationship between the reference position and each of the reference binary symbols in the read target symbol is not configured to have a predetermined positional relationship for each reference binary symbol. As compared with the above, there is an effect that it contributes to the reduction of the load on the process of identifying the presence / absence of the specific color of the pixel.

  According to the invention of claim 7, the presence or absence of a specific color of the pixel is identified as compared with the case where there is no configuration in which a plurality of reference binary symbols are inserted into the reading target symbol so as to have a predetermined interval between each other. The effect that it contributes to the reduction of the load concerning the process to perform is acquired.

  According to the eighth aspect of the invention, it is possible to decode even if the information included in the pattern to be read is expressed by the presence or absence of the specific color of the achromatic color, compared with the case where the specific color is not configured to be achromatic. The effect of contributing to highly accurate decoding of the target information can be obtained.

  According to the ninth aspect of the invention, it is possible to decode even if the information included in the pattern to be read is expressed by the presence or absence of the specific color of the chromatic color, compared to the case where the specific color is not configured to be a chromatic color. The effect of contributing to highly accurate decoding of the target information can be obtained.

  According to the tenth aspect of the present invention, the storage amount of the decoding target information is increased as compared with the case where the reference binary design is not configured to have a pair of differently colored pixels in which any pixel is a specific color. The effect of contributing is obtained.

  According to the invention of claim 11, one of the decoding support binary symbol and the decoding target binary symbol is formed with a pair of achromatic colors and the other is formed with a pair of chromatic colors, and the reference binary symbol is paired with a pair of achromatic colors. A first reference symbol that is formed of an achromatic color and serves as a reference for identifying the presence / absence of a pixel included in one of the decoding support binary symbol and the decoding target binary symbol, and a pair of chromatic colors and a decoding support binary symbol Compared to the case where there is no configuration including the second reference symbol as a reference for identifying the presence or absence of the pixel included in the other of the value symbol and the binary symbol to be decoded, the information included in the symbol to be read is specified as an achromatic color. The effect of contributing to highly accurate decoding of the decoding target information even if the information included in the pattern to be read is expressed by the presence or absence of a specific chromatic color even when expressed in the presence or absence of color Is obtained.

  According to the twelfth aspect of the present invention, each of the first reference symbol and the second reference symbol is deciphered as compared with a case where there is no configuration in which any pixel is a pair of differently colored pixels having the specific color. The effect of contributing to an increase in the storage amount of the target information can be obtained.

  According to the invention of claim 13, the area to be recorded has a quadrangular shape, and the decoding support binary pattern is recorded in at least three corners among the four corners of the area to be recorded and is included in the area to be recorded. Compared to the case where the location support information that supports location specification does not have a configuration including a location support binary design expressed by the presence or absence of a specific color of a plurality of pixels, the position of the pixel included in the read target design is higher. The effect of contributing to accurate identification is obtained.

  According to the fourteenth aspect of the present invention, the position specifying support binary pattern is formed by combining a set of a plurality of adjacent pixels having a specific color and a set of a plurality of adjacent pixels not having the specific color. Compared to the case where the configuration is not provided, an effect of contributing to accurate detection of the position specifying support binary symbol is obtained.

  According to the fifteenth aspect of the present invention, at least one side of the recording target area is inserted at a predetermined position of the recording target area and is included in the reading target pattern by the position specifying support binary pattern. Compared to the case where the support assistance information for assisting the specific support of the position of the pixel does not have a configuration further including the support assistance binary design expressed by the presence or absence of the specific color of a plurality of pixels, the pixels included in the design to be read The effect that it contributes to the high-precision specification of the position of is acquired.

  According to the sixteenth aspect of the present invention, the pixels included in the read target design by the position specifying support binary design that are respectively inserted at predetermined positions of the recording target region along at least one side of the recording target region. Compared to a case where the support assistance information for assisting the specific support of the position does not have a configuration further including a plurality of support assistance binary symbols each represented by the presence or absence of the specific color of a plurality of pixels, the information is included in the reading target design The effect that it contributes to the highly accurate specification of the position of a pixel is acquired.

  According to the seventeenth aspect of the present invention, the pixels included in the read target symbol are compared with the case where there is no configuration in which a plurality of support auxiliary binary symbols are inserted into the recording target region in units of one side of the recording target region. The effect that it contributes to the high-precision specification of the position of is acquired.

  According to the invention of claim 18, when there is no configuration in which a plurality of support auxiliary binary symbols are arranged so that their mutual intervals are aligned in a unit of one side of the recording target area including the position specifying support binary symbols As compared with the above, an effect that the load on the process of specifying the position of the pixel included in the pattern to be read is reduced can be obtained.

  According to the nineteenth aspect of the present invention, compared with the case where the support auxiliary binary design is not inserted into the recording target area along at least one pair of opposite sides of the recording target area, the reading target The effect that it contributes to the highly accurate specification of the position of the pixel contained in a design is acquired.

  According to the twentieth aspect of the present invention, the support is inserted into the recording target area on the line segment connecting each of the auxiliary assistance binary symbols inserted into the recording target area along each side of the pair of opposite sides and is supported. Compared to the case where the information corresponding to the auxiliary information does not have a configuration further including another auxiliary auxiliary binary symbol expressed by the presence or absence of a specific color of a plurality of pixels, the position of the pixel included in the read target symbol is more accurate. The effect of contributing to identification is obtained.

  According to the invention of claim 23, pixels that are included in at least one of the decoding support binary symbol and the decoding target binary symbol and that are within a predetermined distance from the reference binary symbol are identified pixels. As compared with the case where the configuration is not provided, there is an effect that the presence / absence of a specific color of a pixel included in at least one of the decoding support binary design and the decoding target binary design is identified with high accuracy.

  According to the invention of claim 24, when the acquisition means uses the pixel included in the decoding target binary design as the identification target pixel, the reading support further displays the decoding support binary design information indicating the decoding support binary design. Whether the specific color of the identification target pixel indicated by the identification target pixel information acquired by the acquisition unit is acquired based on the reference binary symbol information and the decoding support binary symbol information acquired by the acquisition unit As compared with the case where there is no configuration for discriminating, there is an effect that the presence or absence of the specific color of the pixel included in the binary pattern to be decoded is identified with high accuracy.

It is a block diagram which shows an example of a structure of the recording device which manufactures the two-dimensional code which concerns on 1st Embodiment. It is a block diagram which shows an example of a structure of the two-dimensional code which concerns on 1st Embodiment. It is a block diagram which shows an example of a structure of the mobile telephone with a camera used for the reading of the two-dimensional code which concerns on 1st Embodiment. It is a figure which shows an example of the unclear two-dimensional code where the balance of light and dark was broken. It is a figure which shows an example of the two-dimensional code image binarized by reading the two-dimensional code shown in FIG. It is a flowchart which shows an example of the flow of a process of the two-dimensional code decoding process program which concerns on 1st Embodiment. It is a figure which shows an example of the two-dimensional code with which distribution of brightness has deviation. It is a schematic diagram which shows the insertion modification of a reference | standard binary symbol. It is a schematic diagram which shows the example which inserted the reference | standard binary symbol and the chromatic color reference | standard binary symbol in the division area. It is a figure which shows an example of the conventional two-dimensional code. It is a figure which shows an example of the two-dimensional code which concerns on 2nd Embodiment. It is a figure which shows an example of the two-dimensional code image obtained by image | photographing the two-dimensional code shown in FIG. It is a figure which shows an example of the two-dimensional code image obtained by image | photographing the two-dimensional code shown in FIG. It is a figure which shows an example of the two-dimensional code image when there is no distortion. It is a figure which shows an example of the two-dimensional code image in case there exists distortion. It is the schematic diagram which showed typically the two-dimensional code image shown in FIG. It is the schematic diagram which showed typically the two-dimensional code image shown in FIG. It is a block diagram which shows an example of a structure of the two-dimensional code which concerns on 2nd Embodiment. It is a flowchart which shows an example of the flow of a process of the two-dimensional code decoding process program which concerns on 2nd Embodiment. It is a flowchart which shows an example of the flow of a process of the coordinate setting process program which concerns on 2nd Embodiment. It is a schematic diagram which shows the problem which arises when the conventional coordinate setting process is used. It is a schematic diagram which shows that the problem shown in FIG. 21 is eliminated by the two-dimensional code decoding process which concerns on 2nd Embodiment.

  Hereinafter, an example of an embodiment for carrying out the present invention will be described in detail with reference to the drawings.

[First Embodiment]
FIG. 1 is a configuration diagram illustrating an example of a configuration of a recording apparatus 10 that manufactures a two-dimensional code according to the first embodiment. As shown in FIG. 1, the recording apparatus 10 includes a UI (User Interface) panel 12, a paper feeding unit 14, an image recording unit 16 that is an example of a recording unit, and a discharge table 18.

  The UI panel 12 includes a touch panel display 12A and a switch 12B, and various instructions such as recording of a two-dimensional code on a recording sheet, which is an example of a recording medium, are performed by the user via the touch panel display 12A and the switch 12B. At the same time, necessary items are displayed on the touch panel display 12A. The paper feeding unit 14 accommodates recording paper and feeds the recording paper to the image recording unit 16 as necessary.

  The image recording unit 16 has a so-called printer function for recording an image by a xerographic method, for example. Needless to say, the recording method is not limited to the xerographic method, and may be another recording method such as an inkjet method or a thermal method. When the user instructs the recording of the two-dimensional code onto the recording paper via the UI panel 12, the image recording unit 16 receives the paper fed from the paper feeding unit 14 by operating the paper feeding unit 14. The two-dimensional code is recorded on the recording sheet obtained by the step (2) based on the two-dimensional code information indicating the two-dimensional code, and the recording sheet on which the two-dimensional code is recorded is discharged to the discharge table.

  FIG. 2 shows an example of the configuration of a matrix type two-dimensional code 30 (hereinafter referred to as “two-dimensional code 30”) according to the present embodiment recorded on the recording paper P by the recording apparatus 10 shown in FIG. FIG. As shown in FIG. 2, the two-dimensional code 30 recorded on the recording paper P is a rectangular image in which binarization information is expressed by the presence or absence of a specific color of a plurality of pixels arranged in a matrix. Note that, here, an image having a quadrangular outline is illustrated, but the present invention is not limited thereto, and may be an ellipse or a polygon other than a quadrangle.

  The two-dimensional code 30 according to the first embodiment is a black and white binary symbol which is an example of a symbol to be read. That is, it can be said that it is a binary design in which, for example, black is a specific color and various information is expressed by the presence or absence of the specific color. The two-dimensional code 30 includes a decoding support binary symbol 32 having position / orientation detection symbols 32A to 32D, a decoding target binary symbol 34, and a plurality of reference binary symbols 36. That is, the two-dimensional code 30 is configured by recording a decoding support binary symbol 32, a decoding target binary symbol 34, and a reference binary symbol 36 in a rectangular recording target region 38.

  The recording target area 38 has an outer frame defined by the outline of the two-dimensional code 30 and has a vertically long rectangular shape. Further, the recording target area 38 is divided into a plurality of quadrangular divided areas (divided areas of m rows and n columns). In the first embodiment, the recording target area 38 is divided into divided areas of 4 rows and 3 columns as shown in FIG.

  The decoding support binary pattern 32 is a binary in which the position in the recording target area 38 and the arrangement of the presence or absence of a specific color are fixed regardless of what decoding target information the decoding target binary pattern 34 contains. In addition to the position / orientation detection symbols 32 </ b> A to 32 </ b> D, a pattern (not shown) in which version information indicating the version of the two-dimensional code 30 is expressed and format information indicating the format of the two-dimensional code 30 are expressed. It includes a design (not shown).

  The position / orientation detection symbols 32 </ b> A to 32 </ b> D are symbols for specifying the positions of pixels included in the recording target area 38 and the orientation of the recording target area 38. For this reason, the position / orientation detection symbols 32A to 32D are fixed in the arrangement of the position and the presence / absence of a specific color in the recording target area 38 regardless of the decoding target binary pattern 34, regardless of the decoding target information. ing. For example, each of the position / orientation detection symbols 32A to 32D according to the first embodiment is a square binary pattern, and is a checkered pattern of 2 rows and 2 columns in black and white, which is an example of position specifying support information. Each of the checkered white area and the black area is a set of a plurality of pixels. The position / orientation detection symbols 32 </ b> A to 32 </ b> D are arranged at the four corners of the recording target area 38. In the example shown in FIG. 2, the position / orientation detection symbol 32A is in the divided area of the first row and the first column, and the position / orientation detection symbol 32B is in the divided area of the fourth row and the first column. Position / orientation detection symbols 32D are arranged in the divided area of the fourth row and the third column in the divided area of the first row and the third column, respectively. That is, in FIG. 2, the position / orientation detection symbol 32A is located in the upper left corner of the recording target area 38, and the position / orientation detection symbol 32B is located in the lower left corner of the recording target area 38 when viewed in front. Are arranged in the upper right corner of the recording target area 38 in the front view, and the position / orientation detection symbol 32D is arranged in the lower right corner of the recording target area 38 in the front view. The black-and-white arrangement of the position / orientation detection symbols 32D is different from the black-and-white arrangement of the position / orientation detection symbols 32A to 32C. Therefore, the orientation of the two-dimensional code 30 is specified by reading the position / orientation detection symbols 32A to 32D and specifying the relative positional relationship between the position / orientation detection symbols 32A to 32D. The position of the pixel included in is specified. In the example illustrated in FIG. 2, the position of each pixel included in the two-dimensional code 30 is two with the position of the pixel in the upper left corner of the front view as an example of a specific pixel included in the position / orientation detection symbol 32 </ b> A being the origin. Identified in dimensional coordinates.

  In the decoding target binary design 34, each of a plurality of pixels included in a region other than the decoding support binary design 32 in the recording target region 38 is expressed in white or black according to the decoding target information in units of one pixel. Value design. The decoding target information is encoded information that is decoded by being decoded. The decoding target binary design 34 is a design in which the decoding target information is expressed in white or black for each pixel. The decoding target binary design 34 is read together with the position / orientation detection symbols 32A to 32D, and the decoding target binary design 34 is configured based on the relative positional relationship of the position / orientation detection symbols 32A to 32D specified thereby. The position of each of the plurality of pixels in the recording target area 38 is specified. Specifically, the position / orientation detection symbol 32A is specified by two-dimensional coordinates with the position of the pixel at the upper left corner of the front view as the origin.

  The reference binary symbol 36 is inserted at a plurality of specific positions in the decoding target binary symbol 34. The reference binary symbol 36 includes an identification target symbol including a pixel 33 (hereinafter referred to as “identification target pixel”) that is a target for identifying the presence or absence of a specific color (monochrome in the first embodiment as an example). (In the first embodiment, as an example, the decoding support secondary image 32 and the decoding target binary design 34) are binary symbols used as a reference for identifying the presence or absence of a specific color of the identification target pixel 33. That is, it is a binary design that defines a threshold value used when identifying the presence or absence of a specific color. The reference binary pattern 36 is a pair of black and white pixels. There are four types of orientations of the monochrome pixel array included in the reference binary pattern 36. That is, the four types of orientations referred to here are black and white pixels on the left and right, white and black pixels on the left and right, black and white pixels on the top and bottom, and white and black pixels on the top and bottom. .

  The reference binary design 36 is arranged in the decoding target binary design 34 for each orientation of the row direction (horizontal direction) and the column direction (vertical direction) in a plurality of pixels arranged in a matrix of the recording target region 38. Are inserted according to a predetermined rule (for example, at predetermined intervals). As a result, a plurality of reference binary symbols 36 are arranged at predetermined positions in each divided region. In addition, in the example shown in FIG. 2, the reference binary symbol 36 is inserted in the center of each of the divided areas of the first row and the second column and the divided areas of the fourth row and the second column. Further, a reference binary symbol 36 is inserted from the divided area of the second row and the first column to the divided area of the third row and the first column. In addition, a reference binary symbol 36 is inserted from the divided area of the second row and the third column to the divided area of the third row and the third column.

  FIG. 3 is a block diagram showing an example of the configuration of a camera-equipped mobile phone 40 that functions as a reading device for reading the two-dimensional code 30 and an identification device that identifies the presence or absence of a specific color of a pixel. A mobile phone with camera (hereinafter referred to as “mobile phone”) 40 shown in FIG. 3 includes a call function included in a general fixed telephone such as transmission and reception, and a mail function for creating, transmitting and receiving e-mails. And a portable terminal device having a photographing function for photographing a still image. The mobile phone 40 includes a CPU 40A that controls the overall operation of the mobile phone 40, a RAM 40B that is used as a work area when the CPU 40A executes various processing programs, a ROM 40C that stores various processing programs, various parameters, and the like, A secondary storage unit (in this example, a flash memory) 40D used for storing information, a receiver unit 40E for receiving a call from a call partner, a transmitter unit 40F for transmitting to a call partner, and various information are input. An input unit 40G configured to include a number key, a cross key, and a touch panel included in the touch panel display, and a display unit 40H having a display included in the touch panel display and displaying various types of information. , A camera used to realize the above shooting functions A camera (for example, a digital camera) 40I that shoots a subject and generates and outputs photographed image information indicating an image obtained by photographing is connected to a public telephone communication network via a communication line 42. An external interface (I / F) 40J that is connected to communicate with a mobile phone or other external communication device, and that exchanges various types of information with the external communication device. These units are electrically connected to each other via a system bus 40K. Therefore, the CPU 40A accesses the RAM 40B, ROM 40C, and secondary storage unit 40D, acquires various input information via the input unit 40G, displays various information on the display unit 40H, controls the operation of the camera 40I, and the camera. Acquisition of photographed image information obtained by photographing with 40I, control of operations of the receiving unit 40E and the transmitting unit 40F, grasping operation states of the receiving unit 40E and the transmitting unit 40F, and an external I / F 40J Various information is exchanged with the external communication device.

  In the ROM 40B of the mobile phone 10 according to the first embodiment, a predetermined location (for example, a contour that is predetermined as the contour of the two-dimensional code 30 (the contour of the recording target region 38 as an example)) (for example, As position specifying information that is predetermined as position specifying information for uniquely specifying the position of each divided area from a predetermined vertex) and position specifying information for uniquely specifying the position of the reference binary symbol in the divided area Predetermined reference binary symbol position specifying information is stored in advance.

  By the way, in order to decode the decoding target information indicated by the decoding target binary symbol 34 included in the two-dimensional code 30, first, it is necessary to binarize the decoding support binary symbol 32 and the decoding target binary symbol 34. is there. That is, it is necessary to identify whether each pixel included in the two-dimensional code 30 is white or black using a threshold value.

  However, conventionally, for example, the threshold value used as a reference for identifying white and black of each pixel is set to one fixed value, and as an example, as shown in FIG. As an example, binarization of each pixel included in an image indicated by captured image information obtained by capturing a contrast two-dimensional code with the camera 40I of the mobile phone 40 is performed correctly as shown in FIG. There was something I couldn't do. Even if a predetermined threshold value is assigned to each of the divided areas, it is not a threshold value that reflects the brightness of the actual reading surface of the two-dimensional code 30, and therefore binarization is performed correctly. I will not.

  Therefore, the two-dimensional code 30 according to the first embodiment realizes binarization with higher accuracy than before by providing the reference binary symbol 36 as described above. Then, in the mobile phone 40, a two-dimensional code decoding process is performed in which the two-dimensional code 30 is read by the camera 40I, and the two-dimensional code 30 is binarized and the decoding target information is decoded based on the captured image information obtained by the reading. Is done.

  In the mobile phone 40, various processes for realizing the two-dimensional code decoding process are realized by a software configuration. As an example, there is a form in which a program is executed using a computer. However, the present invention is not limited to such a software configuration. Needless to say, it may be realized by a hardware configuration or a combination of a hardware configuration and a software configuration.

  Below, the case where CPU40A of the mobile telephone 40 which concerns on this Embodiment implement | achieves a two-dimensional code decoding process by executing a two-dimensional code decoding process program is demonstrated. In this case, the two-dimensional code decoding processing program is stored in the ROM 40C in advance, the stored content is stored in a recording medium that can be read by a computer, or distributed via wired or wireless communication means. The form to be applied may be applied.

  FIG. 6 is a flowchart showing an example of the processing flow of the two-dimensional code decryption processing program according to the first embodiment. Here, in order to avoid complications, as an example, a case where still image shooting is performed by the camera 40I of the mobile phone 40 using the two-dimensional code 30 having an uneven brightness distribution as an object as illustrated in FIG. 7 will be described. To do. Here, a case will be described in which there is no distortion in an image obtained by taking a still image with the camera 40I in order to avoid complications.

  In step 100 of FIG. 6, the apparatus waits for an instruction to start shooting. That is, in step 100, when an instruction to start photographing is accepted via the input unit 40G, an affirmative determination is made and the process proceeds to step 102. In step 102, the still image shooting is started by using the shooting function, and then the process proceeds to step 104. In step 104, photographed image information indicating an image of the two-dimensional code 30 (hereinafter referred to as “two-dimensional code image”) is generated and stored in a predetermined storage area (for example, a storage area of the secondary storage unit 40) α. After the storage, the process proceeds to step 106, where it is determined whether or not the still image shooting is completed. If the determination is negative, the process returns to step 104, whereas if the determination is affirmative, the process proceeds to step 108. .

  In step 108, the contour information indicating the contour of the two-dimensional code image indicated by the captured image information stored in the storage area α is extracted from the captured image information, and then the process proceeds to step 110. It specifies by estimating the position of all the division areas based on the division area position specifying information from the outline indicated by the outline information acquired by the process.

  In the next step 112, after specifying by estimating the position of the reference binary symbol in each of the divided regions based on the reference binary symbol position specifying information from each of the divided regions specified by the processing of step 110, Control goes to step 114.

  In step 114, based on the position of the divided area specified by the processing of step 110, a divided area to be noted (target divided area) is determined. That is, one of the divided areas including pixels that have not been subjected to binarization processing (black and white identification) is determined as a target divided area. In the next step 116, the binarization process is still performed for the target divided area determined by the process in step 114, which is included in the two-dimensional code image indicated by the captured image information stored in the storage area α. After the identification target pixel information indicating the identification target pixel 33 that is not a pixel is acquired from the captured image information, the process proceeds to step 118. In step 118, the attention divided area determined by the process of step 114 is indicated by the captured image information stored in the storage area α based on the position of the reference binary symbol specified by the process of step 112. The reference binary symbol information indicating the reference binary symbol included in the two-dimensional code image is acquired from the captured image information.

  In the next step 120, the discrimination target pixel information acquired by the process of step 116 is binarized based on the reference binary symbol information acquired by the process of step 118. That is, a threshold value for identifying black and white of the identification target image is identified from the reference binary symbol information, and the identification target indicated by the identification target pixel information acquired by the processing in step 116 is performed using the identified threshold value. Whether the pixel 33 is white or black is identified. In addition, since a plurality of reference binary symbols are included in the divided area, in this step 120, the binary is based on the reference binary symbol information indicating the reference binary symbol having the shortest distance from the identification target pixel 33. Process. In addition, when there are a plurality of reference binary symbols whose distances from the identification target pixel 33 are not different, a predetermined rule (for example, a reference binary symbol having a shorter distance from the adjacent identification target pixel 33 is shown. Rules for adopting reference binary symbol information, rules for adopting reference binary symbol information indicating a reference binary symbol having the largest pixel value, and reference binary symbols indicating a reference binary symbol having the smallest pixel value The rules for adopting information, the rules for adopting the reference binary design information indicating the reference binary design having the largest average value of the pixel values, and the reference binary design showing the reference binary design having the smallest average value of the pixel values Any one of the reference binary symbols may be determined in accordance with a rule of adopting information or a rule determined by lottery using random numbers.

  In the next step 122, the two-dimensional coordinates indicating the position in the two-dimensional code 30 of the identification target pixel 33 that is the target of the binarization process in step 120 and the result of the binarization process in step 120 are associated with each other. It is stored in a predetermined storage area (for example, a storage area of the secondary storage unit 40) β. As a result, the decoding support binary symbol information indicating the binarized decoding target binary symbol 34 and the decoding target binary symbol information indicating the binarized decoding target binary symbol 34 are stored in the storage area β. .

  In the next step 124, it is determined whether or not there is an identification target pixel 33 for which the binarization processing has not yet been performed by the processing in the above steps 116 to 122, and if negative determination is made, the process returns to step 116. If the determination is affirmative, the routine proceeds to step 126. In step 126, it is determined whether or not there is a divided region including the identification target pixel 33 that has not been subjected to the binarization process. If a negative determination is made, the process returns to step 114, while an affirmative determination is made. If yes, go to Step 128. In step 128, based on the decoding support binary symbol information stored in the storage area β, the decoding target binary symbol information stored in the storage area β is decoded, and then the two-dimensional code decoding processing program is terminated. To do.

  In the first embodiment, the example of the case where the divided region includes a plurality of reference binary symbols 36 has been described. However, the present invention is not limited to this, and as an example, for each divided region as shown in FIG. One reference binary symbol 36 may be inserted into the. In this case, compared to the case where the divided region includes a plurality of reference binary symbols 36, the load on the process of searching for the reference binary symbol 36 present at the position closest to the identification target pixel 33 is reduced. Further, even when one reference binary symbol 36 is inserted for each divided region, the reference binary is specified at a specific position in the divided region (a position uniquely specified by the information corresponding to the above-described reference binary symbol position specifying information). It is good to arrange the pattern 36. This reduces the load on the process of specifying the position of the reference binary symbol 36 as compared to the case where the reference binary symbol 36 is arranged at a different position for each divided region.

  Further, in the first embodiment, the example of the case of performing black and white identification has been described. However, the present invention is not limited to this. For example, as shown in FIG. 9, a reference binary symbol (an example of the first reference symbol) ) And a pair of chromatic color reference binary symbols (an example of a second reference symbol) 50 of a chromatic color (here, white red as an example) may be inserted into each of the divided regions. In this case, for example, one of the decoding support binary design 32 and the decoding target binary design 34 is expressed in black and white (a pair of achromatic colors) and the other is expressed in white red (a pair of chromatic colors). Black and white identification of pixels included in one of the decoding support binary design 32 and the decoding target binary design 34 is performed using a threshold value acquired from the reference binary design 36, and the decoding support binary design 32 and the decoding target Identification of white and red of the pixels included in the other of the binary symbols 34 is performed using a threshold value acquired from the chromatic color reference binary symbol 50. In this case as well, if the reference binary symbol 36 and the chromatic color reference binary symbol 50 are arranged at specific positions in the divided areas (positions uniquely specified by the information corresponding to the reference binary symbol position specifying information described above). good. In this case, compared with the case where the reference binary symbol 36 and the chromatic color reference binary symbol 50 are not arranged at specific positions in the divided areas, the processing for specifying the positions of the reference binary symbol 36 and the chromatic color reference binary symbol 50 is performed. Such a load is reduced.

  The decoding support binary design 32 may be an image combining a pair of chromatic colors and a pair of achromatic colors, or the decoding target binary design 34 may be an image combining a pair of chromatic colors and a pair of achromatic colors. However, it is only necessary to identify a pixel to which an achromatic color (for example, white or black) is applied with reference to the reference binary pattern 36, and to a pixel to which a chromatic color (for example, white or red) is applied. For example, identification may be performed with reference to the chromatic color reference binary design 50.

  In the first embodiment, the pixels included in the decoding support binary design 32 and the pixels included in the decoding target binary design 34 are exemplified as the identification target pixel 33. However, the decoding support binary design 32 and the decoding A pixel included in at least one of the target binary symbols 34 may be the identification target pixel 33.

  Here, the reason why the pixel included in the decoding target binary design 34 may be used as the identification target pixel 33 without using the pixel included in the decoding support binary design 32 as the identification target pixel 33 will be described. In the first embodiment, each of the position / orientation detection symbols 32A to 32D is formed in a checkered pattern of a white area and a black area as shown in FIG. 2 as an example. It is a set of a plurality of pixels. That is, in the decoding target binary symbol 34, the decoding target information is expressed in units of one pixel. Therefore, the failure to binarize one pixel included in the decoding target binary symbol 34 has a great influence on the decoding of the decoding target information. In contrast, in the position / orientation detection symbols 32A to 32D, even if the binarization of one pixel fails, the failure is compensated by error correction processing or the like by surrounding pixels. Therefore, the position / orientation detection symbols 32 </ b> A to 32 </ b> D are considered to perform their functions by the binarization process using the conventional method without performing the binarization process based on the reference binary symbol 36. In other words, the position / orientation detection symbols 32 </ b> A to 32 </ b> D have one pixel included in the binary symbol 34 to be decoded because the areas of the white region and black region to be read are overwhelmingly larger than the area of one pixel. This means that it is detected with higher accuracy than the detection of. Therefore, on the assumption that the position and orientation detection symbols 32 </ b> A to 32 </ b> D reliably specify the direction of the two-dimensional code 30 and the position of the pixel included in the two-dimensional code 30, the identification target pixel 33 is determined as the decoding target binary pattern. It can be said that the number of pixels included in the pixel 34 may be limited.

  In the first embodiment, an example has been described in which a threshold value serving as a reference for identifying black and white is determined by the reference binary symbol 36. However, the present invention is not limited to this. The threshold value may be determined with reference to at least one black and white of the symbols 32A to 32D. For example, the average value of the white area density of the position / orientation detection symbol 32A and the density of the white pixel of the reference binary pattern 36, and the average density of the black area of the position / orientation detection symbol 32A and the reference binary pattern 36 An example in which the threshold value is determined based on the average value with the density of the black pixel is given. Further, the threshold value is determined based on the decoding support binary symbol 32 other than the position / orientation detection symbols 32A to 32D (for example, an image indicating format information or an image defining the reading timing) and the reference binary symbol 36. You may do it.

  In the first embodiment, the two-dimensional code 30 includes a plurality of reference binary symbols 36. However, the reference binary symbol 36 may be singular. Also in this case, binarization processing with higher accuracy is performed as compared with the case where the reference binary symbol 36 is not provided.

  In the first embodiment, a plurality of divided areas obtained by dividing the recording target area 38 into a matrix are illustrated, but this facilitates the processing after the two-dimensional code 30 is read. This is a pre-process for this purpose, and it is not always necessary to obtain a divided region by dividing it into a matrix, and it may be divided in a divided form other than a matrix.

  In the first embodiment, for the sake of convenience of explanation, an example in which the divided area is a quadrangular shape has been described. For example, the reference binary symbol 36 included in each of the two nearest divided areas is used. Is considered to be a Voronoi diagram rather than being divided by a rectangular area.

  Moreover, although the example which inserted the reference | standard binary symbol 36 in the decoding object binary symbol 34 was given in this 1st Embodiment, you may insert in the decoding assistance binary symbol 32 not only this. The chromatic color reference binary symbol 50 may also be inserted into the decoding support binary symbol 32.

  Here, a method of calculating the color threshold will be described. For example, assuming that there is a pixel X that one wants to know whether it is white or black, a color fixed pixel pair P0, P1 near the pixel is determined. Threshold values T0 and T1 are obtained from images obtained by photographing P0 and P1. The average of the threshold values is calculated by assigning weights based on the distance between X and P0, and X and P1, and this is used as a threshold value for determining whether X is white or black.

[Second Embodiment]
In the first embodiment, the binarization processing in the case where there is no distortion in the two-dimensional code image obtained by taking a still image with the camera 40I has been described as an example. However, in the second embodiment, In the embodiment, a binarization process when distortion occurs in the two-dimensional code image will be described. Note that here, components that are not different from those described in the first embodiment are given the same reference numerals as those in the first embodiment, and description thereof is omitted. Also, the description of operations that are not different from the operations described in the first embodiment is omitted.

  FIG. 10 is a configuration diagram showing an example of the configuration of the two-dimensional code 30 described in the first embodiment, and FIG. 11 shows a two-dimensional code 60 according to the second embodiment. The two-dimensional code 60 shown in FIG. 11 is narrower in the horizontal direction than the two-dimensional code 30 shown in FIG.

  12 is a diagram showing an example of a two-dimensional code image obtained by taking a still image with the camera 40I using the two-dimensional code 30 shown in FIG. 10 as a subject. FIG. 13 is a diagram showing the two-dimensional code shown in FIG. It is a figure which shows an example of the two-dimensional code image obtained by taking a still image with the camera 40I using 60 as a subject. Since the two-dimensional code image related to the two-dimensional code 60 has a vertically long and narrow shape compared to the two-dimensional code image related to the two-dimensional code 30, the distortion appears greatly due to the distortion of the lens in the camera 40I. .

  When the two-dimensional code image related to the two-dimensional code 60 is not distorted, for example, one side appears in a straight line as shown in FIG. 14, whereas the two-dimensional code image related to the two-dimensional code 60 is distorted. As an example, one side does not appear on a straight line as shown in FIG. That is, it appears with one side curved. FIG. 16 schematically shows the two-dimensional code image shown in FIG. 14 in an extreme manner, and FIG. 17 schematically shows the two-dimensional code image shown in FIG. 15 in an extreme manner.

  The position of each pixel is expressed by two-dimensional coordinates on the assumption that one side appears in a straight line as shown in FIG. However, if the two-dimensional code image is distorted as shown in FIG. 17, the positions of the pixels included in the two-dimensional code image cannot be specified with high accuracy. Therefore, the decoding target information indicated by the decoding target binary symbol 34 is not accurately decoded.

  Therefore, in the two-dimensional code 60 according to the second embodiment, as shown in FIG. 18, as an example, between the position / orientation detection symbol 32A and the position / orientation detection symbol 32B, and between the position / orientation detection symbol 32C and A plurality of positions for assisting the specific support of the positions of the respective pixels included in the two-dimensional code 60 by the position / orientation detection symbols 32A to 32D along the outline of the two-dimensional code 60 between the position / orientation detection symbols 32D. The position detection auxiliary symbol 62 (an example of a support auxiliary binary symbol) is inserted. In the example shown in FIG. 18, a plurality of position detection auxiliary symbols 62 inserted between the position / orientation detection symbol 32A and the position / orientation detection symbol 32B include the position / orientation detection symbols 32A and 32B. Are arranged at a predetermined distance so that a plurality of position detection auxiliary symbols 62 inserted between the position / orientation detection symbol 32C and the position / orientation detection symbol 32D are positioned / orientated. The detection symbols 32C and 32D are arranged at a predetermined distance so that the distance between them is uniform. Further, the position detection auxiliary symbol 62 has a checkered pattern which is an example of support auxiliary information smaller than each of the position / orientation detection symbols 32A to 32D. In the second embodiment, a checkered pattern is formed by combining two pairs of pixels (pixels in two rows and two columns), but the overall size of the checkered pattern is a position / orientation detection symbol. What is necessary is just to be smaller than each of 32A-32D and larger than the reference | standard binary symbol 36. FIG. The checkerboard pattern is not necessarily required. Moreover, it may be larger than the reference binary symbol 36.

  In the second embodiment, the recording target area 38 is divided into divided areas of 3 rows and 1 column as shown in FIG. In the example shown in FIG. 18, a region surrounded by a broken-line rectangle corresponds to a divided region.

  In the two-dimensional code 60 according to the second embodiment, the position detection auxiliary symbol 62 is arranged so as to face the position detection auxiliary symbol 62 arranged on the opposite side in the row direction. In the example shown in FIG. 18, each of a plurality of position detection auxiliary symbols 62 and a plurality of position detection auxiliary symbols 62 inserted between the position / orientation detection symbol 32A and the position / orientation detection symbol 32B are position / orientation detection symbols. Each of the plurality of position detection auxiliary symbols 62 inserted between 32C and the position / orientation detection symbol 32D is opposed (opposite) in the row direction. A position detection center symbol 64 is inserted in the center between the position detection auxiliary symbols 62 facing directly in the row direction.

  Specifically, a position detection auxiliary symbol 62 adjacent to the position / orientation detection symbol 32A (hereinafter referred to as “position detection auxiliary symbol 62A” in the case of distinction) and a position detection adjacent to the position / orientation detection symbol 32C. Auxiliary symbols 62 (hereinafter referred to as “position detection auxiliary symbols 62C” in the case of distinction) are arranged to face each other in the row direction, and connect position detection auxiliary symbols 62A and position detection auxiliary symbols 62C. A position detection central symbol 64 is inserted at the center of the line segment (the line segment corresponding to the bottom of the upper divided area of the recording target area 38). Further, a position detection auxiliary symbol 62 adjacent to the position / orientation detection symbol 32B (hereinafter referred to as “position detection auxiliary symbol 62B” in the case of distinction) and a position detection auxiliary symbol 62 adjacent to the position / orientation detection symbol 32D. (Hereinafter referred to as “position detection auxiliary symbol 62D” in the case of distinction) are arranged so as to face each other in the row direction, and a line segment connecting the position detection auxiliary symbol 62B and the position detection auxiliary symbol 62D ( A position detection central symbol 64 is inserted at the center on the line segment corresponding to the bottom of the middle divided area of the recording target area 38. In the second embodiment, the plurality of position detection auxiliary symbols 62 are inserted on each side of a pair of opposite sides that intersect with a direction in which distortion of an image obtained by photographing is expected, and face each other. A position detection central symbol 64 is inserted in the center between the position detection auxiliary symbols 62 in the positional relationship under the assumption that the position is not easily affected by image distortion.

  In the two-dimensional code 60 according to the second embodiment, the position of each divided region is determined by the position / orientation detection symbols 32A to 32D and the position detection auxiliary symbol 62. That is, the position detection auxiliary symbol 62 includes the boundary between the upper divided area of the recording target area 38 and the middle divided area of the recording target area 38, and the middle divided area and the recording target area of the recording target area 38. Each of the boundaries with the lower divided area 38 is arranged so as to straddle each boundary in the center, and the specific pixels included in each of the position / orientation detection symbols 32A to 32D and the position detection auxiliary symbol 62 are two-dimensionally arranged. Coordinates are assigned in advance. The position of each divided region is specified by these two-dimensional coordinates.

  FIG. 19 is a flowchart showing an example of the processing flow of the two-dimensional code decryption processing program according to the second embodiment. Here, in order to avoid complications, the two-dimensional code obtained by taking a still image with the camera 40I of the mobile phone 40 using the two-dimensional code 60 with uneven brightness distribution on the reading target surface as a subject. A case where the image is distorted as shown in FIG. 15 will be described as an example. Further, here, in order to avoid complication, the identification target pixel 33 is a pixel included in the decoding target binary design 34, and the decoding target binary design 34 binarized by a conventional binarization processing method or the like is used. A case where the decoding support binary symbol information shown is already stored in the storage area β will be described. Further, here, in order to avoid complications, the pixels included in each of the position / orientation detection symbols 32 </ b> A to 32 </ b> D and each of the specific pixel located at the corner of the two-dimensional code image and each of the position detection auxiliary symbols 62 are included. A case where two-dimensional coordinates are given in advance to each of the included pixels and specific pixels located on the contour of the two-dimensional code image will be described. Here, a case will be described in which, in order to avoid complications, two-dimensional coordinates (for example, two-dimensional coordinates of each vertex of the divided area) defining each divided area are predetermined. Here, a case will be described in which the reference binary symbol position specifying information is set to two-dimensional coordinates in order to avoid complications.

  Here, processing different from the processing of the two-dimensional code decoding processing program according to the first embodiment will be described. Note that the two-dimensional code decryption processing program according to the second embodiment is different from the processing of the two-dimensional code decryption processing program according to the first embodiment described above in that the processing in step 200 is replaced with the processing in step 108. The point that the process of step 110A is applied instead of the process of step 110, the point that the process of step 112A is applied instead of the process of step 112, and the process of step 114A instead of the process of step 114 are applied. The point of application is different.

  In step 200 of FIG. 19, a coordinate setting processing program is executed. FIG. 20 is a flowchart illustrating an example of a processing flow of the coordinate setting processing program. In step 200A of FIG. 20, the position / orientation detection symbols 32A to 32D and the position detection auxiliary symbol 62 included in the two-dimensional code image indicated by the captured image information stored in the storage area α are detected. In the next step 200B, among the position / orientation detection symbols 32A to 32D and the position detection auxiliary symbol 62 detected by the processing of step 200A, the position / orientation detection symbols 32A to 32D and the position detection that form the four corners of the minimum unit. The two-dimensional coordinates given in advance to specific pixels included in each of the auxiliary symbols 62 are acquired. Note that in this step 200B, the four corners for which the two-dimensional coordinates have already been acquired by the processing of this step 200B are excluded from the target of this processing.

  In the example shown in FIG. 18, the “four corners of the minimum unit” are the four corners of the position / orientation detection symbols 32A and 32C, the position detection auxiliary symbol 62A, and the position detection auxiliary symbol 62C, the position detection auxiliary symbol 62A, and the position. There are four corners based on the detection auxiliary symbol 62B, position detection auxiliary symbol 62C, and position detection auxiliary symbol 62D, and four corners based on the position / orientation detection symbols 32B and 32D and position detection auxiliary symbols 62B and 62D.

  In the next step 200C, with reference to the two-dimensional coordinates given to the specific pixels included in each of the four corners of the minimum unit acquired by the processing in step 200B, each pixel included in the two-dimensional code image is referred to. To give two-dimensional coordinates. For example, from the two-dimensional coordinates of the four corners of the minimum unit acquired by the process of step 200B, the two-dimensional coordinates of each pixel included in the quadrangular region (including the side) formed by the four corners of the minimum unit are uniquely derived. Examples of forms that are applied to each pixel are given. As a specific means for uniquely deriving the two-dimensional coordinates of each pixel and giving it to each pixel, it is formed by the above “minimum unit four corners” as information for specifying the position of each pixel when there is no distortion. For each two-dimensional coordinate given in advance to each pixel included in the square area, each two-dimensional coordinate given to a specific pixel included in each of the four corners of the smallest unit and two-dimensional coordinates of the four corners of the smallest unit Each distance determined in advance as a distance from each (for example, a distance determined in advance as a distance from a specific pixel included in the position / orientation detection symbol 32A, or from a specific pixel included in the position / orientation detection symbol 32C) A predetermined distance as a distance, a predetermined distance as a distance from a specific pixel included in the position detection auxiliary symbol 62A, and a specific pixel included in the position detection auxiliary symbol 62C Using a predetermined distance) is associated table as the distance al, it includes means for applying a two-dimensional coordinate to each pixel included in a square region formed by the minimum unit of the four corners. In this case, for example, the two-dimensional coordinates of the four corners of the minimum unit acquired by the process of step 200B are input, and the two-dimensional coordinates of the four corners of the minimum unit associated with the input two-dimensional coordinates of the four corners of the minimum unit are input. As a distance from each of the two-dimensional coordinates, a two-dimensional coordinate of a position satisfying each predetermined distance is output, and the two-dimensional coordinates output here may be given to the target pixel. Also, information that uniquely identifies the relative positional relationship with the two-dimensional coordinates of the four corners of the minimum unit from the two-dimensional coordinates of the four corners of the minimum unit obtained by the processing of step 200B using an arithmetic expression (for example, The two-dimensional coordinates of the four corners of the minimum unit and the distance to each pixel) may be calculated, and the two-dimensional coordinates of each pixel may be calculated based on the calculation result.

  In the example illustrated in FIG. 18, an example in which a plurality of position detection auxiliary symbols 62 are inserted into the two-dimensional code 60 is described. However, the present invention is not limited to this, and the position detection auxiliary symbol 62 may be singular. In this case, for example, if the position detection auxiliary symbols 62B to 62D are removed, the two-dimensional coordinates of each pixel are uniquely determined from the two-dimensional coordinates of the four corners of the position / orientation detection symbols 32A, 32C, 32D and the position detection auxiliary symbol 62A. Examples of derivation are given.

  In order to uniquely derive the two-dimensional coordinates of each pixel, it is not always necessary to derive from the two-dimensional coordinates of the four corners of the minimum unit. For example, the three corners of the position / orientation detection symbols 32A and 32C and the position detection auxiliary symbol 62A The two-dimensional coordinates of each pixel may be uniquely derived from the two-dimensional coordinates. Specifically, position / orientation detection is performed for each two-dimensional coordinate given in advance to each pixel that is a target for derivation of two-dimensional coordinates from the three corners of the position / orientation detection symbols 32A and 32C and the position detection auxiliary symbol 62A. A distance predetermined as a distance from a specific pixel included in the symbol 32A, a distance predetermined as a distance from a specific pixel included in the position / orientation detection symbol 32C, and a specification included in the position detection auxiliary symbol 62A A table or an arithmetic expression in which a predetermined distance is associated in advance as a distance from the pixel is prepared in advance, and the table or the arithmetic expression is included in the rectangular area formed by the four corners of the minimum unit. Two-dimensional coordinates are assigned to each pixel.

  In the next step 200D, it is determined whether or not the processing of step 200B has been executed for all the four corners of the minimum unit. If a negative determination is made, the process returns to step 200B, while an affirmative determination is made. Ends the coordinate setting processing program.

  Returning to FIG. 19, in step 110 </ b> A, a divided area included in the recording target area 38 is specified based on the two-dimensional coordinates given to each pixel by the process of step 200. That is, since the four two-dimensional coordinates that define each divided area are determined in advance, the four divided two-dimensional coordinates are specified by estimating the divided area. In the second embodiment, two-dimensional coordinates are given in advance to specific pixels included in each of the position / orientation detection symbols 32A to 32D and the position detection auxiliary symbol 62. A divided area included in the recording target area 38 is specified.

  In the next step 112A, after specifying by estimating the position of the reference binary symbol in each of the divided regions based on the reference binary symbol position specifying information from each of the divided regions specified by the processing of step 110A, Control goes to step 114A. In step 114A, the target divided region is determined based on the position of the divided region specified by the processing in step 110A.

  As described above, according to the two-dimensional code 60 according to the second embodiment, even if the two-dimensional code image is distorted, the identification target pixel 33 included in the two-dimensional code image is corrected without correcting the distortion. Is determined with high accuracy. Therefore, decoding target information is also decoded with high accuracy. That is, in the conventional case, as shown in FIG. 21, as an example, the two-dimensional coordinates of the four corners of the two-dimensional code image (two-dimensional coordinates given to specific pixels included in each of the position / orientation detection symbols 32A to 32D). Since the position of all the pixels included in the two-dimensional code image has been relied on, when two-dimensional coordinates are given to each pixel on the assumption that each of the four sides of the two-dimensional code image is a straight line When the two-dimensional code image is distorted, the position of the identification target pixel 33 is not specified with high accuracy. On the other hand, in the two-dimensional code 60 according to the second embodiment, for example, as shown in FIG. 22, in addition to the two-dimensional coordinates at the four corners of the two-dimensional code image, Since two-dimensional coordinates (two-dimensional coordinates given to specific pixels included in the position detection auxiliary symbol 62) serving as a reference that contributes to identification are provided, a configuration that relies on the two-dimensional coordinates at the four corners of the two-dimensional code image ( Compared to the configuration shown in FIG. 21, the position of the identification target pixel 33 included in the two-dimensional code image is specified with high accuracy.

  Further, in the second embodiment, an example in which the position of each pixel is specified using the position / orientation detection symbols 32A to 32D and the position detection auxiliary symbol 62 has been described, but the position / orientation detection symbol 32A. The position of each pixel may be specified using the position detection central symbol 64 in addition to .about.32D and the position detection auxiliary symbol 62. In this case, the position of each pixel is specified with higher accuracy.

  In the second embodiment, the size of each of the position detection auxiliary symbol 62 and the position detection center symbol 64 is smaller than each of the position / orientation detection symbols 32A to 32D. However, the present invention is not limited to this. The size of at least one of the position detection auxiliary symbol 62 and the position detection center symbol 64 may be larger than the size of each of the position / orientation detection symbols 32A to 32D. In this case, the position detection auxiliary symbol 62 and the position detection center symbol 64 are accurately detected as compared with the configuration described in the second embodiment. Further, the size described in the second embodiment is not necessary even if the size of at least one of the position detection auxiliary symbol 62 and the position detection center symbol 64 is not larger than the size of each of the position / orientation detection symbols 32A to 32D. If it is larger than this, the position detection auxiliary symbol 62 and the position detection center symbol 64 are detected more accurately than in the configuration described in the second embodiment.

  In the second embodiment, the position / orientation detection symbols 32A to 32D are arranged at the four corners of the recording target area 38, and the position of each pixel is specified by the position / orientation detection symbols 32A to 32D. As an example, if at least three of the position / orientation detection symbols 32A to 32D exist, the position of each pixel is specified.

  In the second embodiment, an example in which a plurality of position detection auxiliary symbols 62 are inserted along each of a pair of opposite sides of the recording target area 38 has been described. A plurality of position detection auxiliary symbols 62 may be inserted along In this case, the position of each pixel is specified with higher accuracy.

In the second embodiment, an example in which two position detection auxiliary symbols 62 are provided for each pair of opposite sides has been described. However, the maximum curvature assumed in the sides of the two-dimensional code image is ignored. The position detection auxiliary symbols 62 may be arranged at an interval of such a degree that the curvature does not affect the specification of each pixel. For example, when a curvature larger than the curvature of the side of the two-dimensional code image shown in FIG. 13 is expected, the second embodiment is implemented by inserting three or more position detection auxiliary symbols 62 on one side. Compared to the configuration according to (a configuration in which two position detection auxiliary symbols 62 are inserted on one side), the position of the pixel is specified with high accuracy. In this way, by identifying each line segment obtained by subdividing the curved side as a straight line, the pixel position can be specified with high accuracy.

DESCRIPTION OF SYMBOLS 10 Recording device 16 Image recording part 30,60 Two-dimensional code 32 Decoding support binary design 32A-32D Position / orientation detection symbol 33 Identification target pixel 34 Decoding target binary design 38 Recording target region 40A CPU
62 Position detection auxiliary symbol 64 Position detection central symbol

Claims (25)

A decoding support binary design in which support information recorded in a specific area in the recording target area and supporting decoding of the decoding target information is expressed by the presence or absence of a specific color of a plurality of pixels, and the specific area in the recording target area A reading target design having a decoding target binary design recorded in an area other than the above and the decoding target information represented by the presence or absence of the specific color of a plurality of pixels;
Inserted at a specific position of the reading target symbol and expressed by the presence or absence of the specific color, and identifies the presence or absence of the specific color of pixels included in at least one of the decoding support binary symbol and the decoding target binary symbol A reference binary pattern in which the reference information for the reference is expressed by the presence or absence of a specific color of a plurality of pixels,
Two-dimensional code including A decoding support binary design in which support information recorded in a specific area in the recording target area and supporting decoding of the decoding target information is expressed by the presence or absence of a specific color of a plurality of pixels, and the specific area in the recording target area A reading target design having a decoding target binary design recorded in an area other than the above and the decoding target information represented by the presence or absence of the specific color of a plurality of pixels;
Inserted at a specific position of the symbol to be read, each represented by the presence or absence of the specific color, and identifies the presence or absence of the specific color of pixels included in at least one of the decoding support binary symbol and the decoding target binary symbol A plurality of reference binary symbols represented by the presence or absence of a specific color of a plurality of pixels,
Two-dimensional code including   3. The two-dimensional image according to claim 2, wherein the reference binary symbol is inserted into each of the divided regions obtained by dividing the recording target region including the decoding support binary symbol and the decoding target binary symbol. code.   The two-dimensional code according to claim 2, wherein a plurality of the reference binary symbols are inserted into each of the divided areas obtained by dividing the design to be read.   The two-dimensional code according to claim 3 or 4, wherein the divided area is an area obtained by dividing the design to be read in a matrix.   6. The positional relationship between a reference position in each of the symbols to be read and each of the reference binary symbols is a predetermined positional relationship for each of the reference binary symbols. The two-dimensional code described in   The two-dimensional code according to any one of claims 2 to 6, wherein the plurality of reference binary symbols are inserted into the reading target symbol so as to have a predetermined interval.   The two-dimensional code according to claim 1, wherein the specific color is an achromatic color.   The two-dimensional code according to claim 1, wherein the specific color is a chromatic color.   The two-dimensional code according to any one of claims 1 to 9, wherein the reference binary design is a pair of differently colored pixels with any pixel as the specific color. One of the decoding support binary design and the decoding target binary design is formed with a pair of achromatic colors and the other is formed with a pair of chromatic colors,
A first reference symbol that is used as a reference for identifying the presence or absence of a pixel that is formed of a pair of achromatic colors and is included in one of the decoding support binary symbol and the decoding target binary symbol; and A first reference symbol that is formed of a pair of chromatic colors and includes a second reference symbol that serves as a reference for identifying the presence or absence of a pixel included in the other of the decoding aid binary symbol and the decoding target binary symbol. The two-dimensional code according to claim 9.   12. The two-dimensional code according to claim 11, wherein each of the first reference symbol and the second reference symbol is a pair of pixels having different colors with any pixel as the specific color. The recording target area is rectangular,
The decoding support binary pattern is recorded in at least three corners of the four areas of the recording target area, and the position specifying support information that supports the specification of the positions of the pixels included in the recording target area is specified for a plurality of pixels. The two-dimensional code according to any one of claims 1 to 12, wherein the two-dimensional code includes a position specifying support binary symbol expressed by the presence or absence of a color.   The two-dimensional image according to claim 13, wherein the position specifying support binary pattern is formed by combining a set of a plurality of adjacent pixels having the specific color and a set of a plurality of adjacent pixels not having the specific color. Dimension code.   Assist in identifying the position of a pixel included in the read target symbol inserted into a predetermined position of the target region to be recorded along at least one side of the target region to be recorded and included in the position target assist binary symbol The two-dimensional code according to claim 13 or 14, wherein the support assistance information to be included further includes a support assistance binary symbol expressed by the presence or absence of the specific color of a plurality of pixels.   Support for specifying the position of a pixel included in the read target symbol by each of the position specifying support binary symbols and inserted at a predetermined position of the recording target region along at least one side of the recording target region. The two-dimensional code according to claim 13 or 14, further comprising a plurality of support assist binary symbols each of which assist assist information is represented by the presence or absence of the specific color of a plurality of pixels.   The two-dimensional code according to claim 16, wherein a plurality of the support auxiliary binary symbols are inserted into the recording target area in units of one side of the recording target area.   18. The two-dimensional code according to claim 17, wherein the plurality of support assistance binary symbols are arranged so that the mutual intervals thereof are aligned in a unit of one side of the recording target area including the position specifying assistance binary symbols.   The two-dimensional according to any one of claims 16 to 18, wherein the support auxiliary binary symbol is inserted into the recording target area along each side of at least one pair of opposite sides of the recording target area. code.   Inserted into the recording target area on a line segment connecting each of the support auxiliary binary symbols inserted into the recording target area along each pair of opposite sides, and corresponds to the support auxiliary information The two-dimensional code according to claim 19, wherein the information further includes another assisting auxiliary binary symbol expressed by the presence or absence of the specific color of a plurality of pixels.   A recording apparatus comprising recording means for recording the two-dimensional code according to any one of claims 1 to 20 on a recording medium. A pixel included in at least one of the decoding support binary symbol and the decoding target binary symbol in the two-dimensional code according to any one of claims 1 to 20 is set as an identification target pixel, and the two-dimensional code is An acquisition means for acquiring identification target pixel information indicating the identification target pixel and reference binary symbol information indicating the reference binary symbol from a reading result obtained by reading by a reading device;
Identification means for identifying the presence or absence of the specific color of the identification target pixel indicated by the identification target pixel information acquired by the acquisition means, based on the reference binary symbol information acquired by the acquisition means;
An identification device including:   The pixel included in at least one of the decoding support binary design and the decoding target binary design, and a pixel within a predetermined distance from the reference binary design is used as the identification target pixel. The identification device described. The acquisition means, when the pixel included in the decoding target binary design as the identification target pixel, further acquires decoding support binary design information indicating the decoding support binary design from the reading result,
The identification means is based on the reference binary symbol information and the decoding support binary symbol information acquired by the acquisition means, and the identification target pixel indicated by the identification target pixel information acquired by the acquisition means The identification device according to claim 22 or 23, wherein the presence or absence of a specific color is identified. Computer
A pixel included in at least one of the decoding support binary symbol and the decoding target binary symbol in the two-dimensional code according to any one of claims 1 to 20 is set as an identification target pixel, and the two-dimensional code is Acquisition means for acquiring identification target pixel information indicating the identification target pixel and reference binary symbol information indicating the reference binary symbol from a reading result obtained by reading by a reading device;
In addition, based on the reference binary symbol information acquired by the acquisition unit, functions as an identification unit that identifies the presence or absence of the specific color of the identification target pixel indicated by the identification target pixel information acquired by the acquisition unit Program to let you.