JP2006110888A - Object - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a two-dimensional code which can be accurately recognized. <P>SOLUTION: This game card 4 is equipped with a first image part which puts a prescribed image into a visually recognizable state in a first direction, and a second image part which puts the two-dimensional code into a visually recognizable state in a second direction. The first image part is formed by displaying a character image etc. on the surface of an object, and the second image part is formed of a light reflection restricting member which puts the two-dimensional code into the visually recognizable state in the second direction by permitting the reflection of light in the first direction, and restricting the reflection of the light in the second direction. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an object holding a two-dimensional code.

In recent years, a technique for recognizing code data by capturing a two-dimensional code with a camera and executing a predetermined process associated with the code data has become widespread. Compared to one-dimensional barcodes, two-dimensional codes have more information that can be encoded, and various types of two-dimensional codes are now available. The code data of the two-dimensional code needs to be read efficiently and accurately from the image data. In view of such a situation, there has been proposed a technique related to image recognition of a two-dimensional code (for example, see Patent Document 1).
JP 2000-82108 A

  In order to improve the reading accuracy of the two-dimensional code, the code data itself may be expressed in a large size. On the other hand, if the size of the object on which the two-dimensional code is printed is limited, the size of the code is inevitably increased. It will also be limited. Therefore, for example, when a two-dimensional code is printed on an object that is not necessarily large, such as a card, it is necessary to place the two-dimensional code on the entire surface of the card, and there is no space for printing other images and the design is excellent. It ’s hard to say. In addition, since the two-dimensional code is recorded on the card by printing, there is a problem that the card can be easily copied by a copying machine, and the value of the card is lowered when counterfeit goods are circulated.

  An object of the present invention is to provide an object that holds a two-dimensional code in consideration of improvement in design and / or prevention of forgery.

  In order to solve the above-described problem, an aspect of the present invention includes a first image portion that makes a predetermined image visible in at least a first direction, and a second direction that is different from the first direction. An object is provided that includes a second image portion that makes the dimension code visible. This object may be a two-dimensional object such as a card or a three-dimensional object. The first image portion only needs to be visible from the user, and the second image only needs to be visible from the imaging device. The first image unit may be visible from the user in the first direction, but may be visible from the user in the second direction. The second image portion may be slightly visible in the first direction, but it is necessary that the visibility in the second direction is higher.

  According to the present invention, it is possible to provide a two-dimensional code in consideration of improvement in design and / or prevention of forgery.

  FIG. 1 shows a configuration of a game system 1 according to an embodiment of the present invention. The game system 1 includes an imaging device 2, an image processing device 10, and an output device 6. The image processing device 10 includes an image analysis device 20 and a game device 30. The image analysis device 20 and the game device 30 may be configured as separate devices, but may be configured as a single unit. The imaging device 2 is a video camera configured by a CCD imaging device or a MOS imaging device, and has a resolution of 320 pixels × 240 pixels, for example. The imaging device 2 images the real space at a predetermined cycle and generates a frame image for each cycle. The imaging region 5 is a range where the imaging device 2 captures an image, and the position and size of the imaging region 5 are adjusted by adjusting the height and direction of the imaging device 2. The game player moves the game card 4 that is a real object with a finger in the imaging area 5. The game card 4 has a two-dimensional code for uniquely identifying itself. In this embodiment, the game card 4 provides at least two different appearances depending on the viewing angle. In the present embodiment, the game card 4 has a first image portion in which a predetermined image is visible in the first direction, and a second image portion in which the two-dimensional code is visible in the second direction. And is configured.

  FIG. 2 shows a state where the game player and the imaging device are looking at the game card from different directions. When the user views the game card 4 from the first direction, for example, from the front, the game card 4 is in a state where a predetermined image can be visually recognized. Note that viewing from the front corresponds to a state where the user views the game card 4 from above with the game card 4 placed on the table 3, that is, a normal situation in which the game card 4 is operated during the game. This image may be, for example, a character image, which can increase the value of the game card 4 for the game player, and when there are a plurality of game cards 4, the user can easily distinguish the game card 4. It becomes possible to do.

  FIG. 3 shows a first image portion in the game card. The first image unit 22 makes the character image visible when the user views the game card 4 from the front. Specifically, the first image portion 22 is formed by displaying (drawing) a character image on the surface of the game card 4. This character may be a character appearing in a game application, or may be a generally popular character. By drawing such a character on the game card 4, the user's attachment to the game card 4 is enhanced and the value of the game card 4 is increased. Thereby, the game card 4 itself can be given commercial value, and it is possible to sell and distribute the game card alone as well as a sales form simply tying it with the game application.

  Returning to FIG. 2, when the imaging device 2 views the game card 4 in the second direction, for example, an angle of about 30 degrees with respect to the game card 4, the game card 4 sends a two-dimensional code to the imaging device 2. Make it visible. When the imaging device 2 is arranged in front of the game card 4, the imaging device 2 captures the character image shown in FIG. 3, but in this embodiment, the imaging direction is the front (90 degrees) with respect to the game card 4. The imaging device 2 is arranged so as to have an angle other than.

  FIG. 4 shows a second image portion in the game card. The second image unit 24 makes the two-dimensional code visible when the imaging device 2 views the game card 4 from an oblique direction. The two-dimensional code need only be visible from the imaging device 2 and does not necessarily exist in a state that can be visually recognized by the user. Note that the second image section 24 shown in FIG. 4 is actually picked up by the image pickup device 2 from an oblique direction, so the aspect ratio of the game card 4 is the same as that of the game card 4 of FIG. However, for the sake of convenience, the aspect ratio is shown as the same.

  In the present embodiment, the second image unit 24 allows the front surface of the game card 4 to reflect light from the front and restricts light reflection in the oblique direction, thereby visually recognizing the two-dimensional code in the oblique direction. It is formed by disposing a light reflection limiting member that is in a possible state. The two-dimensional code is expressed by the positional relationship between the black part and the white part shown in the drawing. This light reflection limiting member may be a polarizing member and plays a role of showing a black portion of the two-dimensional code by blocking light reflection in an oblique direction. The polarizing member may be formed of a resin material, for example. The light reflection limiting member can also be formed of a material having optical characteristics such as TV stone (mineral name: ulexite). It is also possible to use a material that realizes transparency from the vertical direction and realizes non-transparency from other than the vertical direction. In the game card 4 of FIG. 4, the polarizing member is arranged in the portion shown in black, and the polarizing member is not arranged in the portion shown in white. For example, when the polarizing member is viewed from an angle between the parallel plane (0 degrees) and a predetermined angle, the surface of the game card 4 is made invisible, and from the predetermined angle to the vertical (90 degrees). When viewed from an angle between, the surface of the game card 4 is made visible. In other words, the light reflection limiting member limits the viewing angle of the surface of the game card 4 and is imaged from the imaging device 2 at an invisible angle, so that a black portion that does not reflect light is processed as an element of a two-dimensional code. The

  Since the surface of the game card 4 on which the light reflection limiting member is arranged needs to be visible from the user, but cannot be viewed from the imaging device 2, the angle that becomes the boundary between visible and invisible is It is preferable that the angle at which the user views the normal game card 4 and the angle at which the imaging device 2 images the normal game card 4 are determined as a reference. In this embodiment, as the light reflection limiting member, a polarizing member having a polarization characteristic in which an angle that becomes a visible and invisible boundary is between 30 degrees and 45 degrees, for example, is used. Note that this angle is preferably constant regardless of the orientation of the game card 4, that is, even when the game card 4 is rotated on the table 3 with respect to the imaging device 2, there is a polarizing member. It is preferable that the area to be recognized is always recognized as black by the imaging device 2.

  FIG. 5 shows a state in which the black portion of the two-dimensional code shown in FIG. 4 is formed with a polarizing member and the game card 4 is viewed from the front. Currently, some commercially available polarizing members block almost 100% of light reflection in the second direction, but few allow light reflection in the first direction of almost 100%. Therefore, when such a polarizing member is used, when the game card 4 is viewed from the front, a part of the reflected light from the surface is blocked as shown in the figure, and the portion where the polarizing member is arranged appears a little grayish. It will be. However, this does not affect the visibility of the character image. That is, the polarizing member is visually recognized as a thin translucent member when the game card 4 is viewed from the front, and the polarizing member is visually recognized as a black non-transparent member when viewed from an oblique direction. As a method for generating the second image portion 24, for example, a single sheet in which a polarizing member is arranged at a predetermined position may be attached to the surface of the game card 4, and each polarizing member created in a predetermined shape is used. May be affixed to the surface of the game card 4.

  FIG. 6 is a diagram for explaining the positional relationship between the cells in the two-dimensional code shown in FIG. As described above, these cells are composed of polarizing members, and here, a state is shown in which polygon cells having a plurality of predetermined shapes are two-dimensionally arranged according to a predetermined arrangement rule. .

  Specifically, the two-dimensional code of the game card 4 is a two-dimensional arrangement of a reference cell 100 and a plurality of rectangular cells 106 serving as a reference for performing recognition processing of the game card 4 from image data captured by the imaging device 2. Code data portion 102 constituting the code data, and a plurality of corner cells 104a, 104b, 104c, 104d arranged to surround the code data portion 102 (hereinafter collectively referred to as “corner cell 104”) It has. The code data portion 102 and the corner cell 104 exist in the code portion 110 in the two-dimensional code.

  The reference cell 100, the square cell 106, and the corner cell 104 are each configured to have a predetermined shape. The area 108 is formed by connecting a plurality of rectangular cells 106 and constitutes code data together with other rectangular cells 106. When there are a plurality of game cards 4 in the embodiment, the arrangement and size of the reference cell 100 and the corner cell 104 are common, and the game card 4 is uniquely specified by the arrangement of the rectangular cells 106 in the code data portion 102. be able to.

  Details of the two-dimensional code in this embodiment will be described below. Assuming that one side of the square-shaped square cell 106 is one block, the reference cell 100 is a rectangular cell (with a long side in the horizontal direction of 7 blocks and a short side in the vertical direction of 1.5 blocks ( Element). In the embodiment, a square area formed by one vertical block and one horizontal block is called a block area.

  The code data portion 102 is formed in an area surrounded by 7 blocks × 7 blocks. One side of this region is parallel to the long side of the reference cell 100 and is arranged at a position one block away from the long side. As shown in the figure, the code part 110 is an area surrounded by 8 blocks × 8 blocks, and the code data part 102 is included in the area where the code part 110 is formed. The area where the square cells 106 are actually arranged is a portion excluding the area of 2 blocks × 2 blocks at the four corners of the area surrounded by 7 blocks × 7 blocks. That is, the rectangular cell 106 is not arranged in the area of 2 blocks × 2 blocks at the four corners. Therefore, the rectangular cell 106 is arranged in the block area of (7 × 7−2 × 2 × 4) = 33, Configure code data.

  The corner cell 104 a is disposed in the upper left corner area of the code portion 110. This upper left corner area may be within the range of the area of 2 blocks × 2 blocks at the upper left corner of the area surrounded by 7 blocks × 7 blocks as the code data portion 102, or may extend beyond the range. In the example shown in the figure, the corner cell 104a is arranged to protrude 0.5 blocks vertically and 0.5 blocks horizontally from the 2 block × 2 block region in the upper left corner of the code data portion 102. That is, the corner cell 104a exists in the upper left corner region surrounded by 2.5 blocks × 2.5 blocks in the code portion 110. Similarly, the corner cell 104b is disposed in the upper right corner region of the code portion 110, the corner cell 104c is disposed in the lower right corner region of the code portion 110, and the corner cell 104d is disposed in the lower left corner region of the code portion 110. The In the example shown in the drawing, each corner cell 104 is formed in a square shape, specifically, a square cell with one side having a length of 1.5 blocks.

  In the code data portion 102, if one block area is 1 bit, information of 33 bits in total can be encoded. Of these 33 bits, 9 bits constitute check data for confirming that the code data is correct code data. Therefore, information for 24 bits is encoded in the code data portion 102.

  The rectangular cell 106 is an important element that expresses code data, and needs to be accurately recognized by the image analysis apparatus 20. For that purpose, it is ideal to make all the square cells 106 large, but naturally the size of the game card 4 is limited, and the enlargement of the square cells 106 is equivalent to the code data portion. As a result, the number of rectangular cells 106 constituting the number 102 is reduced. This corresponds to reducing the number of bits of information and is not preferable.

  From the above, in this embodiment, the corner cell 104 is configured to have a larger area than the square cell 106. As will be described later, in the image analysis apparatus 20 of this embodiment, the corner cells 104 at the four corners are used to detect the code data portion 102. In other words, if the corner cells 104 at the four corners cannot be detected, the square cell 106 cannot be detected. Therefore, in this two-dimensional code, it is necessary to first reliably recognize the corner cells 104 rather than the square cells 106. is there. By forming the four corner cells 104 larger than the square cells 106, the recognition rate of the four corner cells 104 can be increased.

  Returning to FIG. 1, the output device 6 includes a display 7 which is a display device. The output device 6 may further include a speaker (not shown). Basically, the image processing apparatus 10 displays the frame image captured by the imaging apparatus 2 on the display 7, and controls display so that a character that is a virtual object is superimposed on the game card 4. The player can easily check whether or not the game card 4 is in the imaging area 5 by looking at the display 7. If not, the player can shift the position of the game card 4 or adjust the orientation of the imaging device 2. Then, the imaging device 2 is caused to image the game card 4.

  In the game application of the embodiment, the player operates the character by performing a predetermined operation on the game card 4. Due to the nature of the game application, it is preferable that the player recognize the unity between the game card 4 and the character, and therefore, the character image is displayed superimposed on the game card 4. When the game card 4 is slowly moved within the imaging area 5, the character moves together following the movement of the game card 4 while maintaining the state of riding on the game card 4.

  The movement of the above characters is controlled by the image processing apparatus 10. First, the image analysis device 20 extracts image information of the game card 4 from the frame image acquired by the imaging device 2. Further, the image analysis device 20 extracts a two-dimensional code arranged on the game card 4 from the image information of the game card 4. At this time, the image analysis device 20 determines position information, direction information, distance information, and the like in the space of the game card 4 from the two-dimensional code of the game card 4.

  As will be described later, the image analysis device 20 uses the reference cell 100 and the four corner cells 104 in the image of the game card 4 in the frame image to determine the distance between the imaging device 2 and the game card 4 and the orientation of the game card 4. Calculate and so on. As a result, the character is controlled to face forward on the game card 4. Further, the code data of the game card 4 is acquired from the array of a plurality of rectangular cells in the two-dimensional code.

  The result of the image analysis performed by the image analysis device 20 is sent to the game device 30. Note that the frame image captured by the imaging device 2 may be sent to the game device 30 and image analysis performed on the game device 30 side. In this case, the image processing apparatus 10 is configured by only the game apparatus 30.

  The game apparatus 30 performs display control so that the character is positioned on the game card 4 on the display screen of the display 7 based on the image analysis result in the image analysis apparatus 20. The character may be associated with the code data extracted from the game card 4 and appropriately assigned for each game scene. In this case, when the game scene is switched, the displayed character is also switched. Note that the character printed on the surface of the game card 4 and the character assigned by the code data may be the same. In this case, the player can easily relate the relationship between the game card 4 and the character in the game. Can be recognized.

  The image analysis apparatus 20 extracts candidates for the reference cell 100 in the frame image and assumes a reference cell 100 that satisfies a predetermined reference, and there are four corner cells 104 in the vicinity of the assumed reference cell 100. It is determined whether or not. When the four corner cells 104 are recognized, the image analysis apparatus 20 reads the area surrounded by the four corner cells 104, that is, the arrangement of the rectangular cells 106 in the code data portion 102, and acquires code data. Thereby, it is determined that the assumed reference cell 100 is the true reference cell 100, and the game card 4 can be recognized. The image analysis device 20 calculates and obtains the position and direction of the game card 4 in the virtual three-dimensional coordinate system with the imaging device 2 as a reference (origin).

  FIG. 7 shows the configuration of the image analysis apparatus. The image analysis device 20 includes a frame image acquisition unit 40, a real object extraction unit 42, and a state determination unit 44. The real object extraction unit 42 includes a binarization processing unit 50, a reference cell detection unit 52, a code unit detection unit 54, and a verification processing unit 56. The processing function of the image analysis apparatus 20 in the present embodiment is realized by a CPU, a memory, a program loaded in the memory, and the like, and here, a configuration realized by cooperation thereof is illustrated. The program may be built in the image analysis apparatus 20 or may be supplied from the outside in a form stored in a recording medium. Accordingly, those skilled in the art will understand that these functional blocks can be realized in various forms by hardware only, software only, or a combination thereof. In the illustrated example, the CPU of the image analysis device 20 has functions as a frame image acquisition unit 40, a real object extraction unit 42, and a state determination unit 44.

  The frame image acquisition unit 40 acquires a real space frame image captured by the imaging device 2. The imaging device 2 periodically acquires frame images, and preferably generates frame images at 1/60 second intervals.

  The real object extraction unit 42 extracts a real object image, that is, an image of the game card 4 from the frame image. Specifically, the binarization processing unit 50 converts the frame image into binary bit representation, and expresses the frame image information by turning the bit on and off. The reference cell detection unit 52 detects the reference cell 100 from the binarized data of the frame image. When the reference cell 100 is detected, the code part detection unit 54 detects the code part 110 based on the position of the reference cell 100, and the verification processing unit 56 performs verification processing of the code data included in the code part 110.

  The state determination unit 44 determines the state of the real object in the set coordinate system, and specifically determines the position and direction of the game card 4 and the distance from the imaging device 2. The position information, direction information, and distance information determined by the state determination unit 44 are respectively associated with code data acquired from the two-dimensional code and sent to the game apparatus 30. When a plurality of game cards 4 are present in the imaging area 5, position information, direction information, distance information, and code data are associated with each game card 4 and sent to the game apparatus 30. In the game system 1, the frame image itself is also sent to the game device 30 in order to display the frame image captured by the imaging device 2 on the display 7. The game apparatus 30 reads the character associated with the code data and displays the game card 4 and the character superimposed on each other in a three-dimensional virtual space.

  FIG. 8 is a flowchart showing the processing procedure of the recognition process of the two-dimensional code. The two-dimensional code is imaged by the imaging device 2, and image data for one frame obtained as a result is acquired by the frame image acquisition unit 40. The binarization processing unit 50 performs binarization processing on the image data (S10). In the binarization process, the pixel value of a pixel holding a luminance greater than a predetermined threshold is encoded to “0”, and the pixel is white on display. Hereinafter, a pixel whose pixel value is encoded as “0” in this way is referred to as a white pixel. On the other hand, the pixel value of the pixel holding the luminance value below the threshold is encoded as “1”, and the pixel is black on display. Hereinafter, a pixel whose pixel value is encoded as “1” in this way is referred to as a black pixel. The binarization processing unit 50 collects areas in which black pixels are continuously present as one connected area, and sets (labels) the extracted black pixel connected areas in ascending order from 1 in order. (S12). For example, the labeling numbers may be set in the order in which they are extracted as connected regions, that is, in the specified order. The number is stored in a RAM (not shown) together with the coordinate data. When the two-dimensional code shown in FIG. 2 is used, since the corner cell 104 is displayed larger than the square cell 106, the probability that the corner cell 104 can be detected as a black pixel connection region and the accuracy of the coordinate position can be increased. .

  In this embodiment, since each cell in the two-dimensional code is acquired as black in the frame image, the binarization processing unit 50 recognizes it as a black pixel connection region. On the other hand, as shown in FIGS. 3 and 5, a character image is displayed on the surface of the game card 4. As a result of the binarization process, it is not preferable that the character image is included in the black pixel connection region because it becomes a noise component of the two-dimensional code and adversely affects code recognition. Therefore, the character image is preferably recognized as a white pixel by binarization processing.

  An RGB color filter is arranged in front of the light receiving surface of the imaging device 2, and each pixel value of RGB is recorded as data expressed in 256 gradations for each frame image. In the binarization process, for example, the pixel values of the composite pixels in which the red (R) pixel value is 0 to 100, the green (G) pixel value is 0 to 100, and the blue (B) pixel value is 0 to 100 are obtained. It is encoded to “1” so that the color as a binary image is set to black. On the other hand, the pixel value of a composite pixel in which at least one pixel value of RGB is not within these ranges is encoded as “0”, and the color as a binary image is set to white. In this case, the character image can be binarized as a white pixel by coloring the character image so that at least one of the RGB pixel values exceeds the threshold value of 100.

  In the two-dimensional code recognition process executed before the current target image data, the reference cell detection unit 52 displays the recognized position on the display of the two-dimensional code, for example, the center point of the reference cell 100 in the RAM. It is determined whether it is stored (S14). When the center point of the reference cell 100 in the previous frame is stored in the RAM (Y in S14), the stored position is set as the start point of the reference cell detection process (S16). When the reference cell 100 is detected in the previous image frame, the position of the game card 4 is often not changed greatly in the current image frame, so the center point of the reference cell 100 in the previous frame is used. Thus, the reference cell 100 can be efficiently detected in the current frame. On the other hand, when the position of the two-dimensional code is not stored in the RAM (N in S14), the reference cell detection unit 52 sets the center point on the display 7 as the start point of the reference cell detection process (S18). . After setting the starting point, the reference cell detection unit 52 executes the detection process of the reference cell 100 (S20).

  FIG. 9 is a flowchart showing reference cell detection processing. Note that the number of pixels shown in this flow depends on the resolution of the imaging device 2, and the number of pixels is shown as an example here for easy understanding. First, the reference cell detection unit 52 reads the total number M of black pixel connected regions labeled in S12 of FIG. 8, and initializes a counter value j to 1 (S100). Next, from the start point set in S16 or S18 of FIG. 8, the black pixel connection area is searched along the trace of the counterclockwise spiral on the screen of the display 7, and the black pixel connection area detected first is used as a reference. A cell candidate area is selected (S102). The reference cell detection unit 52 extracts the edge portion of the selected reference cell candidate region, and determines the short side and the long side (S104).

  The reference cell detection unit 52 determines whether or not the short side includes a predetermined number of pixels, for example, 20 pixels or more (S106). The short side is configured with a length corresponding to 1.5 blocks, but when the short side is the reference cell 100 configured with less than 20 pixels, the length of one block is a smaller number of pixels. It will be composed of. Therefore, one side of the rectangular cell 106, which is the smallest component in the two-dimensional code, is about 13 pixels or less, and the image pickup apparatus 2 cannot capture images appropriately. From this, when it is determined that the short side is configured by fewer than 20 pixels (N in S106), it is determined that the black pixel connection region selected in S102 is not the reference cell 100. The process proceeds to S116.

  When it is determined that the short side is composed of 20 or more pixels (Y in S106), the reference cell detection unit 52 uses a pixel whose long side of the reference cell candidate region is a predetermined number of pixels, for example, 300 pixels or less. It is determined whether or not it is configured (S108). For example, if the reference cell 100 is composed of more than 300 pixels on the long side, the length of one block obtained at a ratio of 1 to 7 on the long side becomes large. The lower right corner cell 104c and the lower left corner cell 104d located 8.5 blocks apart from 100 are no longer imaged by the imaging device 2. From this, when it is determined that the long side is composed of more than 300 pixels (N in S108), it is determined that the black pixel connection region selected in S102 is not the reference cell 100. The process proceeds to S116.

  When it is determined that the long side is composed of pixels of 300 pixels or less (Y in S108), the reference cell detection unit 52 determines that the total number of black pixels in the reference cell candidate region is 20 pixels or more and less than 1500 pixels. It is determined whether or not there is (S110). When the total number of black pixels is less than 20 pixels (N in S110), the same problem occurs when the short side is composed of less than 20 pixels, and when the total number is 1500 pixels or more (N in S110). The same problem occurs when the long side is composed of more than 300 pixels. Therefore, in these cases, it is determined that the possibility that the reference cell candidate region is the reference cell 100 is small, and the process proceeds to S116.

  When the total number of black pixels in the reference cell candidate region is 20 pixels or more and less than 1500 pixels (Y in S110), the reference cell detection unit 52 determines the squareness of the reference cell candidate region (S112). The squareness is obtained based on the moment of the reference cell candidate region as described in Patent Document 1 described above. When it is determined that it is not a square (N in S112), it is determined that the reference cell candidate region is not the reference cell 100, and the process proceeds to S116. When it is determined that the pixel is a square (Y in S112), the reference cell detection unit 52 sets the reference cell candidate region as the reference cell 100 (S114), and the labeling number of the black pixel connection region that is set as the reference cell candidate region Is stored in the RAM. In this way, the reference cell 100 can be detected. When only one game card 4 is included in the image data, the reference cell detection process ends when the reference cell 100 is detected. On the other hand, if there is a possibility that a plurality of game cards 4 are included, the process proceeds to S116.

  The reference cell detection unit 52 determines whether or not the count value j is equal to the total number M of reference cell candidate areas (S116). If the count value j has not reached the total number M (N in S116), the count value j is incremented by 1 (S118), and the process returns to the step of S102. On the other hand, when the count value j reaches the total number M (Y in S116), the reference cell detection process is terminated.

  Returning to FIG. 8, when the reference cell 100 is not detected in the reference cell detection process of S20 (N of S22), since the presence of the game card 4 cannot be confirmed, the two-dimensional code recognition process is terminated. On the other hand, when the reference cell 100 is detected (Y in S22), a code part detection process is executed (S24).

  FIG. 10 is a flowchart illustrating the code portion detection process. First, the code part detection unit 54 reads the total number N of the reference cells 100 set in S114 of FIG. 9, and initially sets the counter value k to 1 (S200). Note that the reference cells 100 set in S114 are numbered in the order set. Subsequently, the total number M of the black pixel connection regions labeled in S12 of FIG. 8 is read, and the counter value j is initialized to 1 (S202). The code part detection part 54 detects the black pixel connection area of the number corresponding to the count value j, and selects it as a corner cell candidate area in the lower left corner (S204).

  Next, the code portion detection unit 54 detects that the selected lower left corner cell candidate region is within the search range set in advance for the reference cell 100 of the number corresponding to the count value k detected in S20 of FIG. It is determined whether or not it exists (S206). Since the positional relationship between the reference cell 100 and the corner cell 104d in the lower left corner is predetermined as shown in FIG. 6, it is possible to narrow down the search range for the lower left corner cell from the coordinate data of the reference cell 100. is there. Since the reference cell 100 has a horizontally long rectangular shape, it is possible to set a search range at two positions facing each other across the long side. When it does not exist within the search range (N in S206), it is determined that the black pixel connected region is not the lower left corner cell 104d, and the process proceeds to S232. If it exists within the search range (Y in S206), the black pixel connection region is set as the lower left corner cell 104d (S208).

  After setting the lower left corner cell 104, the code portion detection unit 54 initializes the value l of another counter for counting the number of the black pixel connection region to 1 (S210). The code part detection part 54 detects the black pixel connection area of the number corresponding to the count value l and selects it as a corner cell candidate area in the lower right corner (S212).

  Next, the code part detection unit 54 calculates the ratio between the number of pixels (area) of the lower left corner cell 104d set in S208 and the number of pixels (area) of the lower right corner cell candidate region selected in S212, and the ratio It is determined whether (area ratio) is, for example, 1/6 or more or 6 times or less (S214). In the corner cell 104, the number of pixels acquired changes according to the distance from the imaging device 2. Specifically, it has a large area if it is close to the imaging device 2, and the area is small if it is far away. Therefore, it is assumed that the areas in the image data are different even in the corner cells. However, for example, a case where the ratio of the lower left corner cell to the lower right corner cell is smaller than 1/6 or larger than 6 times (N in S214) cannot normally be assumed. Cannot be regarded as a corner cell in step S226, and the process proceeds to step S226.

  When the area ratio is, for example, 1/6 or more and 6 times or less (Y in S214), the code part detection unit 54 determines the center point of the lower left corner cell 104d and the center point of the lower right corner cell candidate region selected in S212. It is determined whether or not the distance of (2) satisfies a predetermined condition (S216). Here, the predetermined condition may be that the distance between the center points approximates the length of the long side of the reference cell 100, for example. If the predetermined condition is not satisfied (N in S216), the process proceeds to S226, and if the predetermined condition is satisfied (Y in S216), the code portion detection unit 54 sets the black pixel connection region as the lower right corner cell 104c. (S218).

  When the lower left corner cell 104d and the lower right corner cell 104c are set as described above, the code part detection unit 54 changes the set reference cell 100, lower left corner cell 104d, and lower right corner cell 104c to X on the screen of the display 7. Affine transformation is performed in the axial direction and the Y-axis direction (S220). The length of one block is calculated based on the length of the long side or short side of the reference cell 100 set in S20. The code part detection part 54 maps the black pixel connection area included in the area of the code part 110 as a cell from the image obtained by the affine transformation, and generates a code map (S222).

  The code part detection unit 54 detects the corner cells 104 at the four corners from the generated code map cells, and determines whether or not the surrounding three block areas are white pixels (S224). If the three block areas around the corner cell 104 are composed of white pixels (Y in S224), the code map is set as the code part 110 of the two-dimensional code (S230), and the process proceeds to S236. When the three block areas around the corner cell 104 are not white pixels, the process proceeds to S226.

  In S226, it is determined whether or not the count value l is equal to the total number M of black pixel connected regions. If the count value l is equal to M (Y in S226), the process proceeds to S232, and if not equal (N in S226), The count value l is incremented by 1 (S228), and the process returns to S212.

  In S232, it is determined whether or not the count value j is equal to the total number M of the black pixel connected regions. If the count value j is equal to M (Y in S232), the process proceeds to S236, and if not equal (N in S232), The count value j is incremented by 1 (S234), and the process returns to S204.

  In S236, it is determined whether or not the count value k is equal to the set total number N of reference cells 100. If the count value k is not equal to N (N in S236), the count value k is incremented by 1 (S238). , Return to S202. This makes it possible to search for a plurality of two-dimensional codes in the image data. When the count value k is equal to N (Y in S236), the detection process of the code unit 110 is finished as described above.

  Returning to FIG. 8, when the code part 110 is not detected in the code part detection process of S24 (N of S26), since the presence of the two-dimensional code cannot be confirmed, the two-dimensional code recognition process is terminated. On the other hand, when the code part 110 is detected (Y in S26), a code data verification process is executed (S28).

  FIG. 11 is a flowchart showing a code data verification process. As described above, 9-bit check data generated by a predetermined algorithm and 24-bit information data exist in 33-bit code data. In this process, the check data is used to verify the code data. To do. In the following, a process for verifying code data is performed by generating check data from code data based on the check data generated by a predetermined algorithm and collating the check data.

  First, the verification processing unit 56 initially sets a value p of a counter that counts the number of times the reference value calculated in subsequent steps S304 and S308 is shifted to the right by 1 bit to 1 (S300). Next, the verification processing unit 56 calculates code data and check data values from the code map of the code unit 110 (S302).

  The verification processing unit 56 performs an exclusive OR operation between the calculated code data value (bit stream) and 0xFFFFFF (S304), and uses the obtained value (bit stream) as a reference value (reference bit stream). And It is determined whether or not “1” is set in the LSB (Least Significant Bit) of the reference bitstream (S306). When it is determined that “1” is not set (N in S306), the verification processing unit 56 An exclusive OR operation of the reference value (reference bit stream) and 0x8408 is performed (S308), and the value (bit stream) obtained as a result is set as a new reference value (reference bit stream), and the process proceeds to S310. If “1” is in the LSB (Y in S306), the process proceeds to S310 in the same manner.

  The verification processing unit 56 shifts the reference value (reference bit stream) calculated in S304 or S308 to the right by 1 bit (S310), and determines whether or not the count value p is equal to 24 which is a predetermined number of shifts. Determination is made (S312). If it is determined that p is not 24 (N in S312), the count value p is incremented by 1 (S314), and the process returns to S306.

  When it is determined that p = 24 (Y in S312), a logical product operation of the calculated bit stream and 0x1FF is performed (S316). The verification processing unit 56 determines whether or not the value obtained by the logical product operation is equal to the calculated value of the check data (S318). If it is determined that the value is equal (Y in S318), it is detected in S24 of FIG. The code part 110 thus determined is an appropriate pattern as a two-dimensional code, and the code part 110 of the two-dimensional code is determined (S320). If it is not equal to the check code (N in S318), it is determined that there is an error in reading the code part 110, and the code data verification process is terminated. In FIG. 11, only the verification process for one code unit 110 is shown, but when a plurality of code units 110 are detected, this verification process is executed for each.

  Returning to FIG. 8, when the code part 110 is not fixed in the code data detection process of S28 (N of S30), since the presence of the two-dimensional code cannot be confirmed, the two-dimensional code recognition process is terminated. On the other hand, when the code part 110 is confirmed (Y in S30), the value of the code data, that is, the value of the two-dimensional code is stored in, for example, the RAM and held (S32), and the two-dimensional code recognition process is finished. To do.

  As described above, by using the game card 4 described with reference to FIGS. 2 to 4, the imaging device 2 can not only recognize the two-dimensional code but also present a character image to the user. The design can be improved. Further, by configuring the two-dimensional code with the polarizing member, the game card 4 cannot be forged simply by copying, and the rarity value of the game card 4 can be increased.

  Further, by making the corner cell 104 of the two-dimensional code large, the recognition rate of the corner cell 104 in the code part 110 can be increased, and the coordinate position of the corner cell 104 in the two-dimensional coordinate system can be accurately obtained. It becomes possible. Specifically, since the center position of the corner cell 104 can be accurately obtained, the position of the game card 4 can be accurately identified. In addition, by accurately determining the center positions of the plurality of corner cells 104, the positional relationship between the reference cell 100 and the corner cells 104 can be accurately grasped, and the accuracy of affine transformation can be improved. And the direction in which the game card 4 is facing can be accurately specified.

  Hereinafter, a method for obtaining the position and direction of the game card 4 in the three-dimensional coordinate system will be described. In order to determine the position and direction of the virtual three-dimensional coordinate system of the game card 4, in this embodiment, the angle of view of the imaging device 2, the screen resolution, the screen coordinate positions of the four corner cells 104, and the actual corner cells 104 Use distance. The screen is a screen of the display 7 that displays an image captured by the imaging device 2.

(Step 1)
First, the distance from the viewpoint to the screen projection plane is obtained. Here, the distance from the viewpoint to the screen projection plane is obtained from the angle of view of the camera and the screen resolution.
Camera horizontal angle of view: θ
Screen horizontal resolution: W
Distance from viewpoint to screen projection plane: P
Then, the following calculation formula holds.
P = (W × 0.5) / tan (θ × 0.5)

(Step 2)
Next, a three-dimensional vector extending from the viewpoint to each corner cell 104 is obtained.
Corner cell screen coordinate position: SX, SY
Distance from viewpoint to screen projection plane: P
3D vector extending to the corner cell: V
Then, the following calculation formula holds.
V = (SX, SY, P)
Note that the screen coordinate position has the origin at the center of the screen.

(Step 3)
A normal vector of a plane formed by the viewpoint and three points of two adjacent corner cells is obtained. A total of four normal vectors are generated.
A three-dimensional vector extending from the viewpoint to the corner cell 104a: V1
A three-dimensional vector extending from the viewpoint to the corner cell 104b: V2
A three-dimensional vector extending from the viewpoint to the corner cell 104c: V3
A three-dimensional vector extending from the viewpoint to the corner cell 104d: V4
Normal vector of the plane formed by the viewpoint and the corner cells 104a and 104b: S12
Normal vector of the plane formed by the viewpoint and the corner cells 104b and 104c: S23
Normal vector of the plane formed by the viewpoint and the corner cells 104c and 104d: S34
Normal vector of the plane formed by the viewpoint and the corner cells 104d and 104a: S41
Then, the following calculation formula holds.
S12 = V1 × V2
S23 = V2 × V3
S34 = V3 × V4
S41 = V4 × V1
“X” indicates an outer product.

(Step 4)
Subsequently, the direction (coordinate axis) of the game card 4 in three dimensions is obtained. Based on the four normal vectors obtained in step 3, the coordinate axes of the card are obtained.
Card local coordinate X-axis (horizontal direction with respect to the card surface): VX
Card local coordinate Y-axis (direction penetrating the card surface): VY
Card local coordinate Z-axis (vertical direction with respect to the card surface): VZ
Then, the following calculation formula holds.
VX = S12 × S34
VZ = S23 × S41
VY = VZ × VX

(Step 5)
Finally, the three-dimensional position of the game card 4 is obtained. In step 4, the local coordinate transformation matrix of the game card 4 is obtained. If the actual distance between corner cells is known, the position of the card can be easily obtained. If the three-dimensional coordinate position of the corner cell 104a is expressed as a variable, the three-dimensional coordinate positions of the corner cells 104b, 104c, and 104d can be expressed using the variable. Since the screen coordinate positions of the four corner cells are known, the three-dimensional coordinate position of the game card 4 can be specified by solving the simultaneous equations of these calculation formulas.

  In the above, this invention was demonstrated based on the Example. This embodiment is an exemplification, and it will be understood by those skilled in the art that various modifications can be made to the combination of each component and each processing process, and such modifications are also within the scope of the present invention. .

  In the embodiment, the two-dimensional code is set so as to be visually recognized using the polarizing member. However, for example, the two-dimensional code can be generated using a hologram. For example, there are rainbow holograms and Lippmann holograms as types of holograms. A hologram is generated by guiding an object beam having object information and a reference beam on the hologram recording material and recording interference fringes formed by the interference between the object beam and the reference beam. Therefore, a plurality of holograms are recorded on the hologram recording material while changing the incident angle of the reference light so that the character image can be visually recognized in the first direction, and the two-dimensional code is visually recognized in the second direction. It becomes possible to make it possible.

It is a figure which shows the structure of the game system concerning an Example. It is a figure which shows the state which the user and the imaging device are looking at from different directions. It is a figure which shows the 1st image part in a game card. It is a figure which shows the 2nd image part in a game card. It is a figure which shows the state which formed the two-dimensional code shown in FIG. 4 with a polarizing member, and looked at the game card from the front. It is a figure which shows a two-dimensional code. It is a figure which shows the structure of an image analyzer. It is a flowchart which shows the process sequence of the recognition process of a two-dimensional code. It is a flowchart which shows the detection process of a reference | standard cell. It is a flowchart which shows the detection process of a code part. It is a flowchart which shows the verification process of code data.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Game system, 4 ... Game card, 6 ... Output device, 7 ... Display, 10 ... Image processing device, 20 ... Image analysis device, 22 ... 1st image Part, 24 ... second image part, 30 ... game device, 40 ... frame image acquisition part, 42 ... real object extraction part, 44 ... state determination part, 50 ... binary Conversion processing unit, 52... Reference cell detection unit, 54... Code unit detection unit, 56.

Claims (5)

A first image portion that renders a predetermined image visible in at least the first direction;
A second image portion that renders the two-dimensional code visible in a second direction different from the first direction;
An object characterized by comprising: The first image portion is formed by displaying a predetermined image on the surface of the object,
The second image section allows a two-dimensional code to be visually recognized in the second direction by allowing light reflection in the first direction on the surface of the object and restricting light reflection in the second direction. The object according to claim 1, wherein the object is formed by arranging a light reflection limiting member that is in a stable state.   The object according to claim 2, wherein the light reflection limiting member is a polarizing member.   The object according to claim 3, wherein the polarizing member is made of a resin material. The object according to claim 1, wherein the first image portion and the second image portion are generated by multiplex recording of holograms on the object from different angles.

Images