JPH07334604A - Two-dimensional code reading device - Google Patents

Abstract

PURPOSE:To provide a two-dimensional code reading device which can read the data even when a single two-dimensional code is divided into two images. CONSTITUTION:The two-dimensional code reading device is provided with an image reading means 1 which reads a single two-dimensional code after dividing it into two images, a synchronizing pattern extracting means 2 which extracts a synchronizing pattern out of the images, a sampling position calculator means 3 which calculates a sampling positions based on the synchronizing pattern and gives the array numbers to these sampling positions, a sampling position deciding means 4 which decides whether the sampling positions calculated by the means 3 are already sampled and validates only the unsampled positions, a data sampling means 5 which samples the data on the sampling positions and outputs the data and the array numbers, and a data aligning means 6 which aligns the data according to the array numbers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-dimensional code reading device, and more particularly to a two-dimensional code reading device for reading one two-dimensional code by dividing it into two images.

[0002]

2. Description of the Related Art In recent years, as the use of bar codes has expanded, there has been an increasing demand for expanding the data capacity and increasing the density of bar codes, and in order to meet this demand, there are various kinds of two-dimensional codes called two-dimensional codes. Code has been proposed.

A conventional two-dimensional code reading device will be described below. FIG. 10 is a block diagram showing the configuration of a conventional two-dimensional code reading device. In FIG. 10, 21 is an image reading unit that optically reads a two-dimensional code printed on a document or the like, 22 is a synchronization pattern extraction unit that extracts the coordinates in the image of the synchronization pattern included in the two-dimensional code from the image, Reference numeral 23 denotes a sampling position calculation unit that calculates a sampling position from the coordinates of the synchronization pattern, and 2
A data sampling unit 4 samples the data recorded at the sampling position calculated by the sampling position calculating unit. FIG. 11 is a diagram showing a specific example of a two-dimensional code read by a conventional two-dimensional code reading device. In FIG. 11, 25 is an image read by the image reading unit 21, 26 is a horizontal synchronization pattern, 27 is a vertical synchronization pattern, and 28 is a data unit.

The operation of the two-dimensional code reading device constructed as described above will be described below.

First, the image reading unit 21 reads a two-dimensional code on a document to obtain an image 25. Next, the sync pattern extraction unit 22 extracts the horizontal sync pattern 26 and the vertical sync pattern 27 included in the image 25, and calculates the coordinates of each. After that, the sampling position calculation unit 23
The sampling position is the intersection of a straight line that passes through the center coordinates of each horizontal sync pattern and is parallel to the vertical sync pattern sequence, and a straight line that passes through the center coordinates of each vertical sync pattern and is parallel to the horizontal sync pattern sequence. First, C1
The coordinates of the intersections of the straight line passing through and the straight lines passing through R1 to R8, the coordinates of the intersections of the straight line passing through C2 and the straight lines passing through R1 to R8, and C12 are sequentially calculated, and the data sampling unit 24 sets the sampling position The calculation unit 23 determines whether the pixel at the sampling position is white or black in the order in which the sampling position is calculated, and obtains bit data 1 and 0 corresponding to the pixel (for example, Japanese Patent Laid-Open No. 2-50282).

[0006]

However, in the conventional configuration as described above, the data sampling process is performed on the assumption that one image data includes one entire two-dimensional code. There is a problem that a large two-dimensional code that cannot be read unless divided into two images or a two-dimensional code that is tilted and is out of the reading range of the image reading unit cannot be handled.

In view of the above problems of the conventional two-dimensional code reading device, the present invention provides a two-dimensional code reading device capable of reading data from a two-dimensional code divided into two images. It is intended.

[0008]

According to the present invention, a sampling position calculating means for calculating a sampling position and its array element number, and determining whether the calculated sampling position is a sampling position already sampled, The two-dimensional code reading device includes a judging means, a data sampling means for sampling data at unsampling positions, and an aligning means for arranging the sampled data according to an array number.

[0009]

According to the present invention, the sampling position calculating means calculates the sampling position and the array element number corresponding to the sampling position, and the sampling position judging means judges whether the calculated sampling position is a sampling position which has already been sampled. The sampling means samples the data at the non-sampling position, and the aligning means aligns the sampled data according to the array number, so that even if one two-dimensional code is divided into two and read, sampling is performed from each image. The original data can be reconstructed from the created data.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings showing its embodiments.

FIG. 1 shows a second embodiment of the present invention.
It is a block diagram which shows the structure of a dimension code reader. In FIG. 1, 1 is an image reading unit that reads a two-dimensional code by dividing it into two images, 2 is a sync pattern extraction unit that extracts the coordinates of the sync pattern included in the two-dimensional code in the image, and 3 is a sync pattern extraction unit. A sampling position calculation unit that calculates a sampling position for sampling data from the code pattern from the coordinates of the synchronization pattern and gives an array number determines whether the calculated sampling position has already been sampled, Sampling position determination unit that validates only the sampling positions that are not registered, 5 is a data sampling unit that samples the data recorded at the sampling positions that are determined to be valid by the sampling position determination unit, and 6 associates the data with the array element number. It is an aligning part for aligning.

Next, the operation of the two-dimensional code reading apparatus of the first embodiment will be described with reference to FIGS. 1, 2, 3, and 4.

First, the two-dimensional code 8 is read by the image reading section 1.
Are read twice so that there is an overlapping portion, and images 9 and 10 are obtained. The two-dimensional code 8 is composed of a horizontal synchronizing pattern 11 for determining a sampling position, a vertical synchronizing pattern 12 and a data portion 13. The horizontal synchronizing pattern 11 is above and below the data portion 13, and the vertical synchronizing pattern 12 is It is arranged on the left and right of the data section 13. Further, in the data portion 13, a white or black area as a data pattern is arranged at the intersection of a matrix of 8 columns in the vertical direction and 12 columns in the horizontal direction in association with 1 bit of data.

Next, a sampling process of data described below is performed on each of the images 9 and 10.

First, with respect to the image 9, all the horizontal synchronization patterns 11 and the vertical synchronization patterns 12 included in the image 9 are cut out by the synchronization pattern extraction unit 2 to obtain the center coordinates of each synchronization pattern. Sampling position calculator 3
Then, as shown in FIG. 3, C obtained by the synchronization pattern extraction unit 2
A straight line passing through the center coordinates of each horizontal sync pattern 1 to C12 and parallel to the vertical sync pattern row, and R1 to R
The horizontal sync pattern used to obtain each sampling position at each sampling position is defined by the coordinates of the intersection of a straight line passing through the center coordinates of each vertical sync pattern of 6 and parallel to the horizontal sync pattern sequence. The number of the vertical synchronization pattern is given to the sampling position as an array number. That is, the sampling position calculation unit 3 calculates the intersection coordinates (XN, YM) obtained from the Nth horizontal synchronization pattern and the Mth vertical synchronization pattern.
Then, using (N, M, XN, YM) as one sampling position data, the sampling position data corresponding to all possible combinations of N and M are calculated. The sampling position determination unit 4 determines whether the sampling position calculated by the sampling position calculation unit 3 is a sampled sampling position by referring to the data regarding the sampled array number of the sampling position determination unit 4, and determines that the sampling position is not sampled. Only the sampling positions that have been set are valid. The data sampling unit 5 determines whether the pixel at the sampling position determined to be unsampled by the sampling position determination unit 4 is black or white, and passes the corresponding bit data of 1 and 0 and the array number to the alignment unit 6. The alignment unit 6 stores the given bit data together with the array element number. Further, the sampling position determination unit 4 updates the data regarding the sampled array number included in the sampling position determination unit 4 from the sampled array number.

Similarly, the sync pattern is extracted and the sampling position is calculated for the image 10. Since the sampling position determination unit 4 stores data relating to the sampled array numbers corresponding to the bit data sampled from the image 9, the sampling position determination unit 4
Removes the sampling position data corresponding to the bit data already sampled from the image 9 from the sampling position data calculated from the image 10 and passes it to the data sampling unit 5. Similar to the processing performed on the image 9, the data sampling unit 5 samples the data at the given sampling position and passes the bit data and the array number to the alignment unit 6. The alignment unit 6 can obtain meaningful data by aligning the bit data sampled from the image 9 and the bit data sampled from the image 10 according to the array element number.

FIG. 5 is a flow chart showing the above operation.
As described above, according to the present embodiment, the image reading unit 1, the synchronization pattern extracting unit 2, the sampling position calculating unit 3, the sampling position determining unit 4, the data sampling unit 5, and the aligning unit 6 are provided, and the image reading unit 1 is provided. In the sampling position determination unit 4 which determines whether the sampling position data obtained by the synchronization pattern extraction unit 2 and the sampling position calculation unit 3 has been sampled in each of the two images 9 and 10 obtained by dividing the two-dimensional code , The sampling position data that has already been sampled is removed, and the sampling position data is passed to the data sampling unit 5. The data sampling unit 5 passes the sampled bit data and the array number to the alignment unit 6, and the alignment unit 6 sets the bit data according to the array number. The structure in which the data part is surrounded by the synchronization pattern by aligning The 2-dimensional code is not read as a single image with, be divided into two images, and sampled data may be reconstructed into meaningful data.

In this embodiment, the two-dimensional code having the structure shown in FIG. 2 is used as the two-dimensional code. However, if the two-dimensional code has a structure in which the synchronization pattern surrounds the data part, other structures are used. But good.

Further, in the present embodiment, the data sampling section 5 judges whether the pixel at the designated intersection coordinate is black or white, and outputs the bit data of 1 and 0 and the array number corresponding thereto. The determination of black or white is not limited to the pixel at the designated intersection coordinates, but it may be determined by including the pixels around the intersection coordinates, and the pixels used for the determination are white. The color is not limited to black or may include colors other than black and white and halftones, and one data pattern may be configured by the arrangement of pixels of a plurality of colors.
The corresponding data is not limited to bit data, and may be multi-valued data composed of a plurality of bits.

FIG. 6 is a block diagram of a two-dimensional code reading apparatus according to the second embodiment of the present invention. In FIG. 6, 1 is an image reading unit that divides a two-dimensional code into two images and reads the image, 2 is a sync pattern extraction unit that extracts the coordinates of the sync pattern included in the two-dimensional code in the image, and 3 is a sync pattern extraction unit. A sampling position calculation unit that calculates a sampling position from the coordinates of the synchronization pattern and gives an array number, 31 constitutes a part of the sampling position calculation unit 3,
A boundary determining unit that determines the presence or absence of an image data boundary within a fixed range centered on the sampling position, and determines that the sampling position and the array number are valid when there is no image data boundary within the constant range, 4 is a boundary determining unit 31. Sampling position determining unit that determines whether the sampling positions determined to be valid in Sampling are already sampled, and determines only sampling positions that are not sampled to be valid are the sampling positions that are determined to be valid in the sampling position determining unit. A data sampling unit for sampling the data recorded at the position, and 6 is an alignment unit for aligning the data corresponding to the array element number. The image reading unit 1, the synchronization pattern extraction unit 2, the sampling position determination unit 4, and the alignment unit 6 are the same as those in the first embodiment.

Next, the operation of the two-dimensional code reader according to the second embodiment will be described with reference to FIGS. 6 and 7.

First, as shown in the read image in FIG. 8, the image reading unit 1 sets the width of the overlapping portion of the two images to be equal to or more than the square root of 2 of the interval l between the adjacent sampling positions which is given in advance. read. The extraction of the synchronization pattern by the synchronization pattern extraction unit 2 is the same as in the first embodiment.

Next, in the sampling position calculation unit 3, as in the first embodiment, the intersection point coordinates of the straight lines drawn from the horizontal direction synchronization pattern and the vertical direction synchronization pattern obtained by the synchronization pattern extraction unit 2 are used as the sampling position. After the determination, the boundary determining unit 31 determines whether or not each sampling position includes the image data boundary of the image 9 inside a quadrangle centered on the sampling position and having the length of one side equal to the interval l between adjacent sampling positions. However, the sampling position determined not to include the image data boundary is validated. For example,
When the quadrangle 15 is placed around the sampling position 14, the image data boundary is included inside the quadrangle 15, so that the data regarding the sampling position 14 is invalid. The sampling position determination unit 4 and the alignment unit 6 are the same as those in the first embodiment. The data sampling unit 5 obtains the numbers of black and white for the pixels at the sampling positions output by the sampling position determination unit 4 and the pixels surrounding the pixels, and the larger one is taken as the data at the sampling positions, and the corresponding 1, 0 The bit data of and the array element number are passed to the alignment unit 6.

As described above, by providing the boundary judgment unit 31 for judging whether or not the image data boundary is included within a certain range centered on the sampling position, the sampled data due to the lack of the data pattern at the image data boundary is provided. It is possible to prevent a decrease in reliability. In particular, when performing sampling by referring to not only the pixel at the sampling position but also the values of the peripheral pixels at the sampling position, the peripheral pixel to be referred to does not exist in the image data even if the sampling position is in the image data. It is effective because it can happen. Further, since the width of the overlapping portion of the two images is equal to or more than the square root of 2 of the interval l between the adjacent sampling positions, the angle formed by the read image and the two-dimensional code can be set as shown in FIG. Also, it is guaranteed that the sampling position invalidated by the boundary determination unit 31 in one of the two images is not always invalidated by the boundary determination unit 31 in the other image. This is because, in order to prevent two image data boundaries from being applied to a square whose one side length is l centered on one sampling position, the interval between the two image data boundaries is 2 which is the length of the diagonal of the square. This is because it is a necessary and sufficient condition to be square root times.

In the above embodiment, the range in which the boundary determining section 31 determines the presence / absence of the image data boundary is a quadrangle whose length is one side with the length of one side being equal to the interval between adjacent sampling positions. The length of one side is not limited to the interval l of the sampling positions, and is not limited to the quadrangle, as long as the data sampling unit includes a region necessary for sampling data, Further, it may be a polygon that connects the midpoints of the sampling position of interest and the eight sampling positions around it. Further, in the above-described embodiment, the sampling position interval 1 is given in advance, but it may be obtained when the sampling position is calculated.

FIG. 9 is a block diagram of a two-dimensional code reading apparatus according to the third embodiment of the present invention. In FIG. 9, 1 is an image reading unit that reads a two-dimensional code by dividing it into two images, 2 is a sync pattern extraction unit that extracts the coordinates of the sync pattern included in the two-dimensional code in the image, and 3 is a sync pattern extraction unit. A sampling position calculation unit that calculates a sampling position from the coordinates of the synchronization pattern and assigns an array number, 41 determines whether or not data sampling of one of the two images is completed, and the next sampling position is determined according to the determination result. The switching unit for switching the operation of 4 determines whether or not the calculated sampling position is already sampled,
A sampling position determination unit that validates only the sampling positions that have not been sampled, 5 is a data sampling unit that samples the data recorded at the sampling positions that are validated by the sampling position determination unit, and 6 associates the data with the array element number. It is an aligning part for aligning.
The image reading unit 1, the synchronization pattern extraction unit 2, the sampling position calculation unit 3, the sampling position determination unit 4, the data sampling unit 5, and the alignment unit 6 are the same as those in the second embodiment.

Next, the operation of the two-dimensional code reader of the third embodiment will be described with reference to FIG.

First, the process from image reading by the image reading unit 1 to calculation of the sampling position by the sampling position calculating unit 3 is the same as in the second embodiment.

Next, the switching unit 41 determines whether or not one of the two images has been sampled. If not, the process is passed to the data sampling unit 5,
If it has been completed, it is passed to the sampling position determination unit 4.
The operation after the sampling position determination unit 4 or the data sampling unit 5 is the same as in the second embodiment.

As described above, by providing the switching unit 41 that skips the sampling position determining unit 4 depending on the presence or absence of the sampled array element number, the sampling position determination is performed when neither of the two images is unsampled. By omitting the section 4, the processing time can be shortened.

[0031]

As is apparent from the above description, according to the present invention, the sampling position is calculated by calculating the sampling position and assigning the array element number corresponding thereto and the sampling position assigned by the sampling position calculating unit. Since it is provided with a sampling position determining means for determining whether or not the data is sampled, a data sampling means for sampling based on the determination result, and an aligning means for aligning data according to the array number, the image is divided into two images and read. Data can be read from the two-dimensional code.

[Brief description of drawings]

FIG. 1 is a block diagram of a two-dimensional code reading device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an outline of a processed image for explaining the operation in the first embodiment.

FIG. 3 is a diagram showing an outline of a processed image for explaining the operation in the first embodiment.

FIG. 4 is a diagram showing an outline of a processed image for explaining the operation in the first embodiment.

FIG. 5 is a flowchart showing an outline of processing for explaining the operation in the first embodiment.

FIG. 6 is a block diagram of a two-dimensional code reading device according to a second embodiment of the present invention.

FIG. 7 is a diagram showing an outline of a processed image for explaining the operation in the second embodiment.

FIG. 8 is a diagram showing an outline of a processed image for explaining the operation in the second embodiment.

FIG. 9 is a block diagram of a two-dimensional code reading device according to a third embodiment of the present invention.

FIG. 10 is a block diagram of a conventional two-dimensional code reading device.

FIG. 11 is a diagram showing an outline of a processed image for explaining an operation in a conventional two-dimensional code reading device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image reading unit 2 Synchronization pattern extraction unit 3 Sampling position calculation unit 4 Sampling position determination unit 5 Data sampling unit 6 Alignment unit 31 Boundary determination unit 41 Switching unit

Claims (4)

[Claims] 1. A two-dimensional code reading device for reading data from a two-dimensional code in which a data pattern is recorded in a grid pattern in a rectangular area surrounded by a synchronization pattern defining a sampling position, the two-dimensional code reading apparatus performing the reading operation twice. An image reading means for reading a two-dimensional code by dividing it into two images having an overlapping portion, a sync pattern extracting means for extracting a sync pattern from the image, a sampling position based on the sync pattern, and the sampling position A sampling position calculation unit that assigns an array number corresponding to the sampling position, a sampling position determination unit that determines whether the array number is a sampled array number, and a sampling position that is determined to be unsampled by the sampling position determination unit. Data sampling means for sampling data , 2-dimensional code reading apparatus characterized by having an alignment means for aligning the data read by the data sampling unit according to SEQ ID NO. 2. A sampling position calculation means determines whether or not there is an image data boundary within a fixed range centered on a sampling position obtained with reference to a synchronization pattern, and when there is an image data boundary within the fixed range. The two-dimensional code reading device according to claim 1, further comprising a boundary determining unit that invalidates the sampling position. 3. Only when the data sampling of one of the two images is completed, it is determined whether the array element number assigned to the sampling position calculated by the sampling position calculating means is the sampled array element number. The two-dimensional code reading device according to claim 1 or 2, further comprising: sampling position determining means. 4. The width of the overlapping portion of the two images read by the image reading means is at least a square root of 2 times the interval between adjacent sampling positions.
The two-dimensional code reader according to any one of 2 and 3.