JP4948577B2 - Coding method, identification system, and printed product for two-dimensional optical identification - Google Patents

Description

  The present invention relates to the technical field of optical identification, and more particularly to an encoding method and identification system for two-dimensional optical identification (2D-OID), and a printed product having 2D-OID.

  Optical identification (OID) is a technique that makes it possible to conceal digital data in a normal print product and extract the concealed digital data. This digital data is concealed in the normal print product by a standard printing process using normal ink and coexists with the original pattern in the print product. The digital data concealed in the print product can be extracted by optical and image processing techniques provided in the OID pen.

  In the prior art, the encoded figure of each optical identification is usually composed of a plurality of minute information points. These information points are distributed over the block with information contained in the 2D-OID, and the points spread over a block are used to indicate the bit value corresponding to that block. However, such points in 2D-OID typically have a very high density and are not evenly distributed, so if this 2D-OID coexists with the original pattern in a printed product, vision is disturbed. Is lost.

  As shown in FIGS. 1a and 1b, US Pat. In this method, the encoded graphic 10 has a 6 × 6 state area 13 that is divided into a head state area 11 for positioning and a content state area 12 for displaying encoded data. Each state area 13 includes two states, with and without pixels, and the combination of all state areas 13 in the content state area 112 shows the encoded information as shown in FIG. 1b. However, since the combination of the state areas 13 varies with the encoded data, the number and position of 1 vary. That is, the number of pixels is not stationary, and therefore, the pixels of the encoded figure may be densely distributed unevenly. In printed products, when the 2D code coexists with the original pattern, restricting the combination of state areas 13 to prevent the vision from being significantly disturbed, this will result in the encoded data being represented. It has a negative effect on it.

  Another encoding method is disclosed in US Pat. FIG. 2 shows a schematic diagram of an encoded figure design having a plurality of 2D-OIDs. In this design, the encoded graphic (the area indicated by the dotted line) includes key points 2, a plurality of grid points 4, and a plurality of information points 3 in a specified regular array. In this embodiment, the encoded figure is centered on key point 2 and grid points are assigned around this key point, where each of the four grid points 4 is arranged as one rectangular block. The center of the grid point 4 is regarded as a virtual point. The information point 3 in this rectangular block can have an offset (shift) selectively upward, downward, leftward or rightward from the virtual point, thereby different numerical values for identification reading. Represents. The key point 2 is acquired by displacing the grid point 4 at the center of the encoded figure by a certain distance in a specified direction. Keypoint 2 can provide a reference direction for the encoded figure to direct the image for reading and magnification.

  Compared with Patent Document 1, the points disclosed in Patent Document 2 have a more uniform distribution in the encoded drawing, but since each information point is included in the four grid points, the same density in the encoded figure. Under the condition of printing this point, the encoded information represented may be less. The higher the density of information points 3 is, the worse the visual effect is.

  Furthermore, if the encoded figure is formed on a limited object surface area and the information supply is the same, the distribution density of information points will be too high and the distance between two adjacent information points will be too small. . In order to suppress such visual disturbance, the size of the information point is further reduced. If this reduced size is too small, the recognition requirements for printers and papers increase, so data loss during printing can easily appear, which can increase printing difficulty and cause read errors or recognition problems. . On the other hand, if the spacing between information points is increased so that multiple points in the encoded figure do not have too high density, it can reduce the amount of information carried by the 2D-OID. There is.

CN02122633.4 Japanese Patent No. 3706385 (JP3706385)

  Accordingly, it would be desirable to provide improved methods and systems for mitigating and / or avoiding the aforementioned problems.

  An object of the present invention is an encoding method for two-dimensional optical identification (2D-OID), which enables to uniformly distribute the encoding identifiers and thereby bear more encoded information. Is to provide a way to do.

  Another object of the present invention is to provide a printed product in which specific information is concealed, but capable of giving the same gray level effect on vision.

  Yet another object of the present invention is an identification system for two-dimensional optical identification (2D-OID), which suppresses visual interference caused by 2D-OID encoded graphics and thereby more codes It is to provide an identification system that makes it possible to carry information.

  According to one aspect of the invention, an encoding method for two-dimensional optical identification (2D-OID) is provided. The method is: providing a positioning block and a plurality of data encoding blocks around the positioning block; providing a plurality of dots in the positioning block as an NxM array arrangement, where N and M are positive integers Providing a plurality of dots having an NxM array arrangement in each of the data encoding blocks; forming an asymmetric specific pattern by filling a row and a column of dots in the positioning block; and Filling at least one dot in the center of the coding block; and selectively filling the remaining dots of the data coding block to carry information.

  According to another aspect of the present invention, a print product that operates 2D-OID is provided. This 2D-OID includes a positioning block and a data encoding block. The positioning block and each data encoding block each include a plurality of dots having an NxM arrangement, where the rows and columns of these dots are filled in the positioning block to provide an asymmetric singularity for positioning and reading direction identification. At least one dot in the center of each data coding block is filled for positioning, and the remaining dots in each coding block are selectively filled for binary coding. Here, 2D-OID is printed by infrared absorbing ink, identifier graphic is printed by infrared transmitting ink, and N and M are positive integers.

  According to yet another aspect of the invention, an identification system for two-dimensional optical identification (2D-OID) is provided. The system uses an identification device for reading from the object surface at a specific wavelength to obtain a plurality of 2D-OID encoded figures, where the object surface has a plurality of identifier figures. The encoded graphic and the identifier graphic have different optical characteristics, each encoded graphic has a positioning block and a plurality of data encoding blocks around the positioning block, and the positioning block is an NxM array. The data encoding block has a plurality of specific patterns arranged in the NxM array. In the positioning block, the rows and columns of dots are padded to form an asymmetric specific pattern for identifying the reading direction, and at least one dot at the center of each data coding block is padded for positioning. The remaining dots of each data coding block are selectively filled for binary coding, where N and M are positive integers. The identification device identifies the encoded graphic on the surface of the object and outputs information.

  Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings.

1a and 1b are schematic diagrams of 2D-OID encoded figures and corresponding information in the prior art. It is a schematic diagram of another typical coding figure of 2D-OID in a prior art. It is a schematic diagram of the encoding figure in arrangement | positioning of multiple 2D-OID by the embodiment of this invention. FIG. 4 is a schematic diagram of the 2D-OID encoded graphic of FIG. 3 according to an embodiment of the present invention. FIG. 6 is a schematic diagram of another encoded figure of 2D-OID according to an embodiment of the present invention. FIG. 6 is a schematic diagram of an encoded figure of the 2D-OID positioning block of FIG. 5 according to an embodiment of the present invention. FIG. 6b is a schematic diagram of another encoded figure of the 2D-OID positioning block of FIG. 6a, in accordance with an embodiment of the present invention. FIG. 6 is a schematic diagram of an encoded figure of the 2D-OID data encoding block of FIG. 5 according to an embodiment of the present invention. FIG. 6 is a schematic diagram of another encoded figure of the 2D-OID data encoding block of FIG. 5 according to an embodiment of the present invention. It is a schematic diagram of another encoding figure of the data encoding block of 2D-OID by the embodiment of this invention. FIG. 3 is a schematic diagram of a 2D-OID 2 × 3 array of encoded graphics according to an embodiment of the present invention. 3 is a flowchart of an encoding method for 2D-OID according to an embodiment of the present invention; 1 is a schematic diagram of a 2D-OID identification system according to an embodiment of the present invention. FIG.

  FIG. 3 is a schematic diagram of an encoded figure in an arrangement of a plurality of 2D-OIDs 10 according to an embodiment of the present invention. 4 is a schematic diagram of the single 2D-OID 10 encoded graphic of FIG. 3 according to an embodiment of the present invention, presented for clarity. As shown in FIG. 4, the 2D-OID 10 includes a positioning block 101 and eight data encoding blocks 102 to 109. These nine blocks constitute a 2D-OID encoded figure. The eight data encoding blocks 102 to 109 and the positioning block 101 are arranged as a 3 × 3 magic circle having nine squares indicated by dotted lines. The positioning block 101 is designed so that the optical reader can identify the reading direction of the 2D-OID. Therefore, the hollow circles or dots on the left and upper sides of the positioning block are filled with black for positioning. Further, the center dot of each data encoding block 102 to 109 is also filled in to become a reference point for assisting positioning, and the remaining hollow dots are also called data points and represent binary numbers. That is, in this case, the data encoding blocks 102 to 109 represent 000, 001, 010, 011, 100, 101, 110, and 111, respectively. Thus, each data encoding block can include 3-bit data. The remaining four dots of the positioning block 101 can be data points representing 00, 01, 10, and 11, respectively. Therefore, this positioning block 101 can contain 2-bit data. The hollow circles or dots in FIG. 4 show the specific pattern that should be filled by 2D-OID. It is noted that the specific pattern of 2D-OID shows the position and shape of the filled area. Although the profile of each specific pattern is depicted in FIG. 4, the actual encoded pattern in the printed product is obtained by printing the desired specific pattern that is filled, and the unfilled specific pattern is not printed. That is, as shown in FIG. 3, the single 2D-OID 10 has a positioning block 101 in which hollow dots, for example, hollow dots on the left side and the upper side are filled for positioning, Data encoding blocks 102 to 109, which are filled with the hollow dots and serve as reference points for assisting positioning. Looking at the encoded graphics in the 2D-OID 10 arrangement of FIG. 4, positioning can be achieved with the help of the reference points of the positioning block and the data encoding block, and two adjacent 2D-OIDs. Is known not to be confused. As shown in FIG. 4, even if there is no spacer or identifier between these 2D-OIDs 10, adjacent 2D-OIDs do not interfere with each other.

  In this embodiment, the data is encoded in a data encoding block, where each data dot represents a different binary code for the 3-bit binary code, except for the center dot, and each data code Each block has at most one filled data dot. Further, 2-bit data can be encoded also in the positioning block. In addition to the positioning dots, the positioning block 101 further has four hollow dots, which can be used as data dots in which only one data point is filled.

  The 3 × 3 magic square OID indicates a code word. Eight data coding blocks in each 3 × 3 magic square can take an arbitrarily defined coding order. With current technology, it is usually possible to obtain a density of 800 dots per inch (dots per inch, DPI). With the advancement of optical reading technology, this encoding is getting smaller and smaller. In this case, a 1 inch square size can contain 88 codewords. Further, in this embodiment, each 2D-OID has 9 blocks from 101 to 109, and two hollow dots out of 9 hollow dots in each data encoding block, that is, one reference dot. And only one data dot is constantly filled. Filled hollow dots (also called filled dots) are generally distributed relatively uniformly and have a relatively low density. Since the spacing between dots with the same gray level for vision and the filling dots is related to the size of the filling dots, the more dense or uniform the dots are, or the smaller the filling dots are, the more visual It becomes more unclear. When the spacing between the filled dots is about 0.17 mm ± 0.02 and the diameter of each dot is about 0.04 mm ± 0.02, a visual gray level ambiguity appears. Therefore, if the 2D-OID filled dots are very small, for example, with a resolution of 800 DPI, the same gray level will appear in the human eye, so that vision is not easily interfered with. That is, if such encoding is used in a printed product where the pitch between the filled dots is greater than 0.19 mm and the size of each filled dot is less than 0.06 mm, the information is stored in the printed product. It is possible to keep secret. Therefore, such coding is quite comfortable for the eyes and can carry more coding information if the same vision is ignored.

  Further, as compared with a typical 2D-OID, a positioning block corresponding to a data encoding block of 2D-OID has a characteristic that its range is smaller, so that positioning can be realized quickly. Since the positioning block is arranged at the center of the entire 2D-OID, only a few positioning dots are required to achieve a favorable positioning action, so that more data dots are more in the 2D-OID. It is left to carry a lot of information. The actual pattern may be deformed after imaging, or there is a problem that the positioning dots of the positioning block exhibit an encoded figure appearance similar to the filling dots of the data encoding block. The filling dot used as a reference to aid positioning in the data coding block is placed in the center of the block, so only a few dots are needed to perform good positioning assistance, and error Code correction is performed.

  The above embodiment describes one possible type of 2D-OID with the same gray level, but the size of the 2D-OID, the size of the data coding block, the size of the positioning block, the placement of the specific pattern, and One skilled in the art knows that the fill collar can have different designs in different companies. Thus, the present invention does not limit the type. That is, according to the stored data, a specific number of dots forming a specific pattern is extracted from the position corresponding to the specific pattern to be encoded and filled in each data encoding block, The embodiment meets the spirit of the present invention and meets the same gray level characteristics.

  Next, another 2D-OID is presented as an example that allows one skilled in the art to exercise the spirit of the present invention.

  FIG. 5 is a schematic diagram of another encoded figure of 2D-OID according to an embodiment of the present invention. As shown in FIG. 5, in this embodiment, the 2D-OID includes one positioning block 201 and eight data encoding blocks 202-209. The eight data encoding blocks 202 to 209 and one positioning block 201 also form a 3 × 3 magic square. Since the positioning block 201 is arranged at the center of the 3 × 3 magic square, the optical reader that reads this 2D-OID can identify the reading direction. Therefore, adjacent dots on the left side and the upper side of the positioning block 201 are filled. However, in different designs, the positioning blocks are unique to determine the direction and pattern, so those skilled in the art will therefore consider positioning blocks as other filling dot combinations, for example, the right and top sides that intersect each other, It can be designed as a combination of dots on the right and bottom sides, left and bottom sides, or other row and column sides, preferably as a combination of smaller ranges and unique patterns. Furthermore, the number of filling dots may be a number other than nine. The central dot of the data encoding blocks 202 to 209 can be filled as a reference to assist in positioning. Data encoding dots can be estimated based on the spacing between the positioning block and the geographic location of each central dot of the data encoding block relative to the positioning block, so the data code to assist in positioning It is necessary to fill the center dot of the block. Similarly, the filling dot of each data coding block designed by those skilled in the art is not limited to the center dot. For example, it is possible to fill other dots in the center.

FIG. 6a is a schematic diagram of an encoded figure of the 2D-OID positioning block 201 of FIG. 5, according to an embodiment of the present invention. As shown in FIG. 6a, 9 dots (ie, hollow circles) of the positioning block 201 are filled, and the remaining 16 dots represent 16 different 4-bit binary codes ranging from 0000 to 1111. It is possible. The position of each dot can indicate which 4-bit binary code is represented. The relationship between the dot position and the data can have various settings. Next, FIG. 7 is a schematic diagram of an encoded figure of the 2D-OID data encoding block of FIG. 5 according to an embodiment of the present invention. As shown in FIG. 7, in this embodiment, there are 24 dots in addition to the reference dots. These 24 dots consist of three sub-blocks: one with 8 dots in the upper left corner, the other with 8 dots in the lower right corner, and the last one with 4 dots in the upper right corner and 4 in the lower left corner. It is possible to divide into dots. The 8 dots in each sub-block can represent 8 different 3-bit binary codes ranging from 000 to 111, and the position of each dot indicates which 3-bit binary code is represented. Decide. The relationship between the dot position and the data can be set separately for each block. In this embodiment, each data encoding block 202 to 209 has three dots to be filled as data dots, except for the reference dot used for positioning assistance. Therefore, a total of four dots are filled in each data encoding block 202 to 209. These filled dots may exhibit two ^nine different values. 6b is a schematic diagram of another encoded graphic of the 2D-OID positioning block of FIG. 6a, according to an embodiment of the present invention. The positioning and identification reading direction can be determined as long as the asymmetric specific pattern formed from the columns and rows of dots is filled.

FIG. 8 is a schematic diagram of another encoded figure of the 2D-OID data encoding block of FIG. 5 according to an embodiment of the present invention. In this embodiment, each data encoding block has 24 dots in addition to the reference dots. These 24 dots are six sub-blocks: the first is 4 dots in the upper left corner, the second is 4 dots in the lower left corner, the third is 4 dots in the upper right corner, the fourth is 4 dots in the lower right corner, the fifth Can be divided into 4 dots on the central vertical line and 6th includes 4 dots on the central horizontal line. The four dots in each sub-block can represent four types of 2-bit binary codes ranging from 00 to 11, and the position of each dot determines which 2-bit binary code is represented. In this embodiment, each data encoding block 202-209 has six dots that can be filled for use as data dots, with the exception of the reference dot used for positioning assistance. Therefore, a total of 7 dots are filled in each data encoding block 202 to 209. These filled dots can represent 2 ¹² different values.

Thus, a data encoded block can be divided into a plurality of sub-blocks, where each sub-block has 2 ⁿ dots, whereby n is a positive integer greater than 1 It is possible to carry data encoded by bits. The value of n may affect the density of filling points that make up the encoded graphic.

FIG. 9 is a schematic diagram of another encoded figure of a data encoding block of 2D-OID according to an embodiment of the present invention. In this embodiment, the 9 dots in the center of the block are filled, but these 9 dots are used as reference dots to assist in positioning. Thus, each data encoding block 202 to 209 has 16 remaining dots, which represent 16 different 4-bit binary codes ranging from 0000 to 1111. In this case, each data encoding block 202 to 209 has a total of 10 dots filled as data dots and can represent 2 ⁴ (16) different values.

  Although 5x5 data encoding blocks and positioning blocks are presented as examples of encoding schemes, those skilled in the art can realize the objectives of the present invention in 4x4, or 6x6, and sometimes NxM sizes. I can understand that. Therefore, the present invention is not limited to the above example. Further, hollow circles and filled circles, or dots, are presented as examples in the foregoing embodiments, and those skilled in the art will be able to exchange these hollow and filled circles without departing from the spirit and scope of the present invention. That is, it is possible to obtain a desired result similar to a circle without limiting the circle to another shape, for example, a triangle, square, oval, square, regular pentagon, hexagon, etc. It is possible to change to the shape to be.

  Another example shown in FIG. 10 is presented to perform an NxM encoding setup. FIG. 10 is a schematic diagram of a 2D-OID 2 × 3 array of encoded graphics according to an embodiment of the present invention. As shown in FIG. 10, the positioning block 701 and each of the data encoding blocks 702 to 709 include 2 × 3 dots. In this case, in the positioning block 701, the dots on the left side and the upper side that intersect with each other are filled, and the remaining dots are not used. The central two dots of each data encoding block 702 to 709 are filled as reference dots for assisting positioning, and the remaining four dots represent different 2-bit binary codes in the range of 00 to 11, respectively. Thus, this 2D-OID, formed from a positioning block and a data encoding block, can be encoded to represent 16-bit data. The order of encoding each data encoding block can be set as desired.

  In view of this embodiment, those skilled in the art will appreciate that the present invention can be adapted to encode 2D-OIDs and achieve the same gray level effect even in non-square blocks. Thus, the present invention is not limited to squares.

  Furthermore, although the data encoding block and positioning block are arranged in a 3x3 magic square shape, those skilled in the art will use other arrangements, for example, positioning blocks, plus, inner and outer layer data encoding blocks. Would also be possible. The inner layer has 8 blocks, the outer layer has 16 blocks, and the positioning block and the data encoding block can form the encoded figures shown in FIGS.

  Therefore, it is possible to realize the flowchart of FIG. 11 in which an encoding method for 2D-OID is shown. As shown in FIG. 11, this encoding method includes the following steps.

  Step S110 provides a positioning block, a plurality of data encoding blocks around the positioning block, and a plurality of dots in each data encoding block, and these dots are arranged in the NxM array in the data encoding block.

  As seen in FIGS. 4 and 5 where a 3 × 3 magic square arrangement is shown, a plurality of dots are also provided in the positioning block and arranged in an NxM array. Here, N and M are positive integers.

  In step S111, dots adjacent to the first and second sides in the positioning block are filled, and at least one dot in the center of each data coding block is filled.

  Step S112 extracts a specific number of dots from the remaining dots of each data coding block based on the data to be stored, and fills the extracted dots.

For example, from the data encoding block of FIG. 4, one dot for carrying data is extracted to represent 3-bit data, or from the data encoding block of FIG. 5 using the design of FIG. Extract three dots to carry the data, thereby encoding 9-bit data, where 512 different numbers are represented. As shown in FIG. 8, the six dots carrying the data are extracted from the data encoding block of FIG. 5, thereby encoding 12-bit data, in this case 2 ¹² (4096) different numbers. Is represented.

  Step S113 extracts another specific number of dots from the remaining dots of the positioning block based on the data to be stored, and fills the extracted dots.

  Accordingly, it is possible to select another specific number of dots for carrying data from the remaining dots of the positioning block. One skilled in the art can understand that the essential function of the positioning block is to enable the optical reader to identify the reading direction. Therefore, whether the positioning block is used to encode the data is determined by the chosen design, and therefore the 2D-OID encoding method is not limited to it (use).

  Accordingly, another encoding method for 2D-OID is provided, including the following steps.

Step 1 provides a 3x3 magic square shaped figure. In this figure, one positioning block is at the center and eight data coding blocks are at the periphery. Each data coding block has L sub-blocks, and the first sub-block has 2 ^kl specific patterns to carry data. Where L is a positive integer, 1 = 1, 2,. . . L. Each specific pattern can represent a _kl -bit binary code, where _kl is a positive integer. Different specific patterns of dots represent different binary codes, and multiple dots in the positioning block are filled for positioning.

  Furthermore, at least one dot at the center of each data coding block is filled to assist in positioning.

  The encoded figure of the positioning block is not limited to the NxM array, and may be the same as the arrangement of the data encoded block. The encoded figure is not limited to the filling of two vertical adjacent side dots, but instead a filling of an asymmetric specific pattern formed from a single row dot and a single row dot, e.g. used for positioning blocks by known techniques, Other arrangements and filling schemes are possible.

  The dots of each block can be arranged in an NxM array, preferably N is equal to M. In this case, N = M = 3 or N = M = 5, but preferably, the dot that assists positioning in the data coding block is the same as the center dot. Preferably, each sub-block has the same number of dots, for example 2, 3, 4 or a different number than 2, 3, 4 dots.

  Preferably, in the positioning block, adjacent dots on two mutually orthogonal sides are filled, for example, completely or partially, for example, 3 and more consecutive dots on each side with a dark color .

  Alternatively, the dots of each data encoded block of a 3x3 magic square can be arranged as a circular array. This circular array includes one dot used as a reference point and 4 or 8 uniformly distributed dots used as data dots on a circumference centered on the reference dot. This positioning block takes the form of an NxM array. The encoding of these dots is the same as in the previous embodiment. Such a scheme can carry a larger amount of information and suppresses the visual interference caused by the coded figures.

  Dots carrying data, assisting positioning, or positioning dots may be the same or different, and their shapes have the same shape and different sizes, such as circles, squares, or polygons Therefore, the positioning and reference dots may be identified according to the positioning dots. Filled dots are filled and inevitably seen, but other dots need not necessarily be displayed, and in particular need not be displayed for media printed with 2D-OID. Thus, if the encoding is performed by a computer procedure, only the dot position and shape data need be stored in the document.

  The 3 × 3 magic square encoded figure can be modified in the same manner as other encoded figures having a symmetrical structure with the positioning block as the center. In this embodiment, the data encoding block includes the same number of sub-blocks and corresponding positions. Each sub-block has the same number of dots and corresponding positions. Dots at the same position indicate the same binary code. However, in other embodiments, there may be one or more different coded graphics, which does not detract from the object of the present invention.

Step 2 encodes the binary data based on the encoding order in which the data encoding block is set to the segment, and assigns it to the corresponding data encoding block. Each data encoding block sequentially encodes _kl- bit data based on an encoding arrangement for setting sub-blocks and assigns the data to the first sub-block. That is, a specific pattern of dots of _kl- bit data equal to the binary code represented in the first sub-block is filled in, where 1 = 1, 2,. . . L.

  If the number of bits is not sufficient to encode a sub-block of binary data to be encoded, it is possible to encode the remaining data in the sub-block by filling in the set word code. Thus, the remaining sub-blocks, or data encoding blocks, can be used to encode the fill word code and complete the encoding.

In this step, if there are remaining dots in the positioning block to carry data, the encoding is similar to that in the data encoding block, ie L ′ sub-blocks for encoding Is divided. The 1'th sub-block has 2 ^{kl '} specific pattern dots to carry data. Each dot of this specific pattern represents a binary code with different bits. Data, _'if it is coded in bits, equal to the binary code represented, k _l' k l bit data, dots of a specific pattern is fitted. Here, L ′ and k _{l ′} are positive integers, and 1 ′ = 1, 2,. . . L.

  Step 3 obtains the encoded 2D-OID encoded figure after the data carrying the specific pattern of dots is completely filled according to the binary data to be encoded.

  Next, one or more encoded 2D-OID encoded figures are printed on the printed product, thereby obtaining a printed product in which the confidential information is encoded. Since the visual interference caused by 2D-OID in this printed product is small, it has the same gray level effect on vision.

  In practice, a system is provided for identifying a printed product printed with the above-described encoded figure of 2D-OID shown in FIG. In the figure, a schematic diagram of a 2D-OID identification system is presented. This identification system includes a printed product 910 on which 2D information is printed, and a 2D-OID identification device 920. In another embodiment, the printed product may be an object printed on another surface with a 2D-OID encoded graphic.

  The print product 910 includes a 2D-OID layer 912 having a plurality of 2D-OID encoded figures, and an identifier layer 914 having one or more identifier figures. The 2D-OID layer 912 is obtained by printing with infrared absorbing ink. The identifier layer 914 is obtained by printing with infrared transmission ink. Therefore, the identifier graphic print information does not affect the reflection and absorption of light. A 2D-OID encoded graphic is overlaid with a corresponding identifier graphic and includes an identifier graphic. The identifier is related to the encoded information of the encoded figure. The identifier graphic may be one of a picture, a sentence, and a code, or a combination thereof.

  The 2D-OID identifier device 920 includes an optical reader 921, a processing device 922, and an output device 923. The optical reader 921, the processing device 922, and the output device 923 can be connected by wire or wirelessly.

  The optical reader includes an optical package, an optical sensor, and an infrared transmitter. The infrared transmitter illuminates the printed product 910. The optical package filters the infrared light reflected by the printed product, thereby ensuring that only the infrared light is transmitted to the optical sensor. Since the 2D-OID layer 912 is obtained by printing with infrared absorbing ink and the identifier layer 914 is obtained by printing with infrared transmitting ink, the sensor receives the infrared light reflected by the 2D-OID layer 912. Correspondence information consisting of an enlarged coded figure is generated. The optical sensor may be a CMOS sensor, for example.

  The processing device 922 receives the encoded graphic image generated by the optical sensor, identifies the encoded information, for example, the identifier name and number encoded in the encoded graphic, and based on this encoded information, Relevant information, for example, audio and video associated with the identifier is acquired. The output device 923 outputs the encoded information and / or related information as a specified format, for example, LCD or audio output.

  According to the 2D-OID coded graphic described above, the processing device detects a positioning block having dots of the positioning pattern, and the data for the positioning block in the interval between the two points in the positioning block and in the 3 × 3 magic square. Directly estimate the position of the filled data dot based on the relative geographical position of the encoded block and determine which data points are filled in the encoded figure based on the filled data point found at the estimated position To do.

  Since the encoded figure is deformed after visualization and the coded figure of the data coding block and the positioning block may be approximated, an error is generated using the reference point at the center of the data coding block to assist positioning. Perform code correction. Specifically, when the processing device detects a dot in the positioning pattern, it detects the relative distance of the data encoding block relative to the positioning block in the spacing between two points in the positioning block and in a 3 × 3 magic square. Based on the geographic location, the location of the reference point is found, and further, based on whether a reference point is detected at each estimated location, it is determined whether the detected positioning block is an error code or not. Once the positioning block is determined, the processing device in the image based on the spacing between the two points in the positioning block and the relative geographical position of the data encoded block relative to the positioning block in the encoded graphic, To estimate the position of the data points, possibly filled around the reference point, and to obtain the corresponding binary code based on the filled data points found at the estimated position, which data points in the encoded figure Check to see if it was filled. The binary codes corresponding to the data points are sequentially combined, thereby obtaining the data encoded in the encoded graphic.

  The identification device 920 may be an optical identification pen.

  As described above, the present invention includes a positioning block and a data encoding block around the positioning block, and these blocks are arranged in a 3 × 3 magic square shape or a shape having positioning block symmetry. Furthermore, each data coding block is provided with an NxM dot array. Once a complete or partial dot on two adjacent sides of the positioning block is filled, the optical identification device can verify the reading direction. In addition to the specific pattern of central dots, a specific number of dots are filled in the data encoding block, so if the encoding is applied to a printed product, it will be visible as long as the encoding is sufficiently small. At the same gray level effect. That is, the present invention can conceal encoded information on a printed product.

  While the present invention has been described with reference to preferred embodiments thereof, many other modifications and variations may be made without departing from the spirit and scope of the invention as claimed hereinafter. It must be understood that it is feasible.

Claims (17)

An encoding method for two-dimensional optical identification (2D-OID) comprising:
Providing a positioning block and a plurality of data encoding blocks around the positioning block;
Providing a plurality of dots with an NxM array arrangement in the positioning block, where N and M are positive integers;
Providing a plurality of dots having the NxM array arrangement in each data encoding block;
Filling one row and one column of the dots to form an asymmetric specific pattern in the positioning block, filling at least one dot in the center of each data coding block; and
Selectively filling the remaining dots of the data encoded block to carry the information.   2. The encoding method according to claim 1, wherein the asymmetric specific pattern is formed by the dots on two intersecting sides in the positioning block.   The encoding method according to claim 1, wherein the number of the data encoding blocks is 8, and the data encoding blocks and the positioning blocks constitute a 3x3 magic circle.   The N and M are both 3, and the number of remaining dots in each data encoding block is 8, and each of the 8 dots represents a 3-bit binary code. Encoding method.   The code according to claim 1, wherein N and M are 3, the number of filling dots in the positioning block is 5, and the remaining 4 dots in the positioning block represent a 2-bit binary code. Chemical method.   N and M are both 5, and the remaining 24 dots are divided into 6 sub-blocks, and each of the 4 dots in each sub-block represents a 2-bit binary code, or 3 The encoding method according to claim 1, wherein the sub-block is divided into eight dots in each sub-block, each representing a 3-bit binary code.   The N and M are both 5, the number of filling dots in the positioning block is 9, and the remaining 16 dots in the positioning block represent a 4-bit binary code. Encoding method.   The encoding method according to claim 1, characterized in that the asymmetric specific pattern in the positioning block is used for positioning and reading direction identification.   A print product that operates 2D-OID, and the 2D-OID includes a positioning block and a data encoding block, and each of the positioning block and each data encoding block includes a plurality of dots having an NxM arrangement. Wherein, in the positioning block, the rows and columns of dots are filled to form an asymmetric specific pattern for positioning and reading direction identification, and at least one dot in the center of each data coding block. Are padded for positioning, and the remaining dots of each data coding block are selectively padded for binary coding, where the 2D-OID is printed with infrared absorbing ink and the identifier The figure is printed with infrared transmitting ink, and N and M are positive integers. That, print products. An identification system for 2D-OID, wherein an identification device for reading an object surface by a specific wavelength is used to obtain a plurality of 2D-OID encoded figures, wherein the object The surface further includes a plurality of identifier graphics, the encoded graphics and identifier graphics having different optical characteristics, each encoded graphic comprising a positioning block and a plurality of data codes around the positioning block. A positioning block or a data coding block each having a plurality of dots arranged in an NxM array;
In the positioning block, the rows and columns of dots are filled to form an asymmetric specific pattern for identifying the positioning and reading direction, and at least one dot at the center of each data coding block is used for positioning. And the remaining dots of each coding block are selectively padded for binary coding, where N and M are positive integers;
The identification device identifies an encoded graphic on the object surface and then outputs information;
An identification system characterized by that.   N and M are both 3, the number of remaining dots in each data coding block is 8, and each of the 8 dots represents a 3-bit binary code, and the number of filling dots in the positioning block is 5 11. The identification system according to claim 10, wherein the remaining 4 dots of the positioning block represent a 2-bit binary code.   N and M are both 5, and the remaining 24 dots are divided into 6 sub-blocks, and each of the 4 dots in each sub-block represents a 2-bit binary code, or 3 sub-blocks. 11. The identification system according to claim 10, wherein the identification system is divided into blocks, and each of the 8 dots in each sub-block represents a 3-bit binary code.   The N and M are both 5, the number of dots of the asymmetric specific pattern is 9, and the remaining 16 dots of the positioning block represent a 4-bit binary code. Identification system. The identification device is:
An optical reader for capturing an image of the encoded graphic from the object surface;
A processing device for determining the asymmetric specific pattern from the encoded graphic, determining the remaining dots in the encoded graphic, thereby identifying information encoded in the encoded graphic; and
An output device for outputting the information;
The identification system according to claim 10, further comprising:   The identification system according to claim 10, wherein the number of the data encoding blocks is 8, and the data encoding blocks and the positioning blocks constitute a 3 × 3 magic circle.   The identification system according to claim 10, wherein the encoded graphic and the identifier graphic are superimposed on each other.   The identification system according to claim 10, wherein the object surface represents a printing surface, the encoded graphic is printed with infrared absorbing ink, and the identifier graphic is printed with infrared transmitting ink.

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