Identification code detection device and identification code detection method

Abstract

To provide an identification code detection device capable of accurately identifying code information of multiple identification codes using a simple method.SOLUTION: An identification code detection device 10 of the present invention comprises: an image capturing unit 11 for acquiring image information including (multiple) images of identification codes 4; a distance measurement unit 13 for measuring a distance from the image capturing unit for each of the multiple identification codes 4 extracted from the image information; a distance map generation unit 14 for generating a distance map showing a relationship between object distances and focusing ranges using distance measurement results for the identification codes 4; and an identification code detection unit 15 for detecting code information of the identification codes 4 using image information acquired according to a focusing range in the distance map.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an identification code detection device that detects an identification code attached to a package. [Background technology]

[0002] As a technology for managing cargo in a warehouse, a method for managing the presence and location of cargo in the warehouse by reading identification codes attached to the cargo has been implemented. For example, Patent Document 1 proposes a system that uses a scanner to read identification marks that identify the products to be managed and the locations where the products are located, compares the read actual product number data with product data stored in a database, and rewrites the product inventory records in the database. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-101424 Summary of the Invention [Problem to be solved by the invention]

[0004] When using a scanner to read identification codes to identify products under management in a warehouse or the like, it is necessary to read the identification codes of a large number of products under management during inspections at the time of arrival and shipment, which places a heavy burden on the human labor required to read the identification codes.Recently, technology has been put into practical use that allows multiple identification codes to be read simultaneously using high-resolution cameras mounted on mobile devices such as smartphones, but when photographing multiple identification codes simultaneously with a mobile device camera, if there are a large number of identification codes to photograph, it is necessary to maintain a certain distance between the camera and the package, and as a result, the photographing resolution deteriorates depending on the distance between the camera and the package, and it may not be possible to accurately detect all of the identification codes.

[0005] The present invention has been made to solve the above problems, and has as its object to provide an identification code detection device that can accurately detect code information of multiple identification codes in a simple manner. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the identification code detection device of the present invention comprises an imaging unit that acquires image information including an image of an identification code; a distance measurement unit that extracts areas of the identification codes from first image information acquired by the imaging unit, the area including multiple identification codes, and measures the distance from the first imaging unit for each of the extracted areas of the identification codes; a distance map generation unit that generates a distance map showing the relationship between the subject distance and the focus range using the measurement results of the distance measurement unit; and an identification code detection unit that detects code information of the identification codes using second image information acquired by the imaging unit in accordance with the focus range in the distance map, wherein the imaging unit acquires the second image information including at least one of the identification codes in the focus range that includes the distance to the identification code areas, in accordance with a focus drive position determined based on the focus range and the distance to the identification code areas, and the identification code detection unit detects the code information of the identification codes in the second image information.

[0007] In addition, the distance map generation unit may generate the distance map in which the focus range is set so that the distances of multiple identification code areas are included in at least one of the focus ranges, and the imaging unit may acquire the second image information that includes multiple identification codes within the focus range set in the distance map.

[0008] In order to solve the above-mentioned problems, an identification code detection method of the present invention is an identification code detection method executed by an identification code detection device including an imaging unit that acquires image information including an image of an identification code, a distance measurement unit that measures the distance from the imaging unit to an area of ​​the identification code in the image information, a distance map generation unit that generates a distance map indicating the relationship between subject distance and focus range using the measurement result of the distance measurement unit, and an identification code detection unit that detects code information of the identification code using second image information acquired by the imaging unit in accordance with the focus range in the distance map, the method comprising the steps of: the imaging unit acquiring first image information including an image of the identification code; and the distance measurement unit detecting the area of ​​the identification code in the first image information including a plurality of identification codes acquired by the imaging unit. The method includes the steps of: extracting areas of the identification code from the first imaging unit, and measuring the distance from the first imaging unit for each of the extracted areas of the identification code; generating a distance map showing the relationship between the subject distance and the focus range using the measurement results of the distance measurement unit; and detecting code information of the identification code using second image information acquired by the imaging unit in accordance with the focus range in the distance map, wherein the imaging unit acquires the second image information including at least one of the identification codes in the focus range that includes the distance of the identification code area, according to a focus drive position determined based on the focus range and the distance of the identification code area, and the identification code detection unit detects code information of the identification code in the second image information.

[0009] In addition, the distance map generation unit may generate the distance map in which the focus range is set so that the distances of multiple identification code areas are included in at least one of the focus ranges, and the imaging unit may acquire the second image information that includes multiple identification codes within the focus range set in the distance map. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide an identification code detection device that can accurately detect code information of a plurality of identification codes using a simple method. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 shows an example of a system configuration including an identification code detection device according to an embodiment of the present invention. [Figure 2] FIG. 2 is an example of a functional block diagram of an identification code detection device according to an embodiment of the present invention. [Figure 3] FIG. 3 is a diagram for explaining measurement of the distance of an identification code in the embodiment of the present invention. [Figure 4] FIG. 4 is a diagram illustrating an example of a distance map according to the embodiment of the present invention. [Figure 5] FIG. 5 is a diagram for explaining another example of the distance map in the embodiment of the present invention. [Figure 6] FIG. 6 shows an example of an operation flow of the identification code detection method according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention can be embodied in various embodiments and is not limited to the embodiments of the invention described below.

[0013] <Configuration of the luggage management system> Fig. 1 shows an example of a system configuration including an identification code detection device according to an embodiment of the present invention. The identification code detection system 1 in Fig. 1 is composed of an identification code detection device 10 that acquires an image of a piece of luggage 2, each of which has an identification code 4 attached thereto, placed on a pallet 3, and detects code information of the identification code attached to the piece of luggage 2 using the acquired image of the piece of luggage, and an identification code management server 20 that manages the code information of the identification code detected by the identification code detection device 10.

[0014] Recently, technology has been put into practical use that allows multiple identification codes to be read simultaneously using high-resolution cameras installed on mobile devices such as smartphones. However, when photographing multiple identification codes simultaneously using a mobile device camera, if there are a large number of identification codes to photograph, a certain distance must be maintained between the camera and the luggage. As a result, the photographing resolution deteriorates depending on the distance between the mobile device camera and the luggage, and it may not be possible to accurately detect all of the identification codes.

[0015] In this embodiment, when detecting code information of multiple identification codes 4 assigned to luggage 2 placed at positions with different distances, the imaging unit 11 acquires image information (first image information) containing the multiple identification codes 4, extracts the identification codes 4, measures the distance between the extracted identification codes and the imaging unit 11, generates a distance map showing the relationship between the subject distance and the focus range using the measured distance, determines the focus drive position of the imaging unit 11 according to the focus range in the generated distance map, and detects the code information of the identification codes 4 using the image information (second image information) of the identification codes 4 acquired at the determined focus drive position.

[0016] By determining the focus drive position of the imaging unit 11 according to the focus range in a distance map created according to the distance between the imaging unit 11 and the identification code 4, it is possible to obtain images of multiple identification codes in focus within one focus range, making it possible to detect code information of multiple identification codes 4 at positions with different distances with fewer focus drive operations, without having to perform focus drive operations for each individual identification code.

[0017] <Configuration of the Identification Code Detector> FIG. 2 is an example of a functional block diagram of an identification code detection device according to an embodiment of the present invention.

[0018] The identification code detection device 10 comprises an imaging unit 11 for acquiring a photographed image including the identification code 4, a distance sensor unit 12 for measuring the distance to the identification code 4, a central processing unit that measures the distance to the identification code 4 using the distance sensor unit 12 to generate a distance map and detects code information of the identification code 4 using the generated distance map, a memory unit 16 for storing various information, etc., an input unit 17 for the photographer to input information, a display unit 18 for displaying the detection status of the identification code 4, and a wireless unit 19 for transmitting information to the identification code management server 20.

[0019] The central processing unit functions as a distance measurement unit 13 that measures the distance to the identification code 4 using the distance sensor unit 12, a distance map generation unit 14 that generates a distance map showing the relationship between the subject distance and the focus range using the measurement results of the distance measurement unit 13, and an identification code detection unit 15 that detects the code information of the identification code 4 using the image information acquired by the imaging unit 11 according to the focus range in the generated distance map.

[0020] The identification code detection unit 15 determines the focus drive position of the imaging unit 11 according to the focus range in a distance map that shows the relationship between the subject distance and the focus range, which is generated using the distance measured by the distance measurement unit 13, and detects the code information of the identification code 4 using the image information of the identification code 4 acquired by the imaging unit 11 at the determined focus drive position.

[0021] This allows images of multiple identification codes 4 included in one focus range to be acquired in focus, making it possible to detect code information of multiple identification codes 4 at positions with different distances with fewer focus drive operations, without having to perform focus drive operations for each individual identification code 4.

[0022] The storage unit 16 stores the measured distance information of the identification code 4 and a distance map generated using the measured distance information. The identification code detection unit 15 determines the focus drive position of the imaging unit 11 according to the focusing range in the distance map stored in the storage unit 16, and can detect the code information of the identification code 4 using the image information of the identification code acquired by the imaging unit 11 at the determined focus drive position.

[0023] A general-purpose RGB camera can be used as the imaging unit 11. For example, a digital camera or a smartphone equipped with an RGB camera can be used as the identification code detection device 10 equipped with the imaging unit 11. A general-purpose distance measurement sensor such as a TOF (Time of Flight) sensor or a LiDAR sensor can be used as the distance sensor unit 12.

[0024] The identification code detection device 10 can be configured by a computer equipped with a CPU, a memory, and an interface for connecting to external devices.

[0025] <Measurement of the distance between the identification code> 3 is a diagram for explaining measurement of distances of identification codes in an embodiment of the present invention. In the example of Fig. 3, a plurality of packages 2, each having an identification code 4, are placed on a pallet 3.

[0026] The identification code detection device 10 extracts areas of the identification codes 4 from image information containing multiple identification codes 4 acquired by the imaging unit 11, and measures the distance (L1-L5) from the imaging unit 11 for each of the extracted areas of the identification codes 4.

[0027] In the example of Figure 3, image information containing multiple images of the identification code 4 attached to the baggage 2 is acquired, and the area of ​​the identification code 4 is detected in the acquired image information. Extraction of this area of ​​the identification code 4 is sufficient if the position of the identification code can be identified on the image, even if the identification code itself cannot be read. Detection of the identification code area can be achieved, for example, by detecting the frequency components of the identification code. The area of ​​the identification code may also be estimated using the results of learning the identification code 4.

[0028] <Distance map generation> In this embodiment, when detecting code information of multiple identification codes 4 attached to luggage 2 placed at positions with different distances, the distance between the imaging unit 11 and the identification codes 4 is measured, and the measured distance is used to generate a distance map showing the relationship between the subject distance and the focusing range. Figures 4 and 5 are diagrams for explaining examples of distance maps in this embodiment of the present invention.

[0029] 4 and 5 are distance maps that show the relationship between the subject distance and the focus range. The image capture unit 11 has a focus range (depth of field) centered on the focus position, and the image capture unit 11 has a focus range (depth of field) that corresponds to the focus drive position.

[0030] 4 is an example of a distance map having five focus ranges (F1-F5). The focus drive position of the imaging unit 11 is determined based on the distance between the focus ranges in the distance map and the identification code 4.

[0031] In Figure 4, the identification code 4 can be detected by setting the focus drive position of the imaging unit 11 to the focus position D1-D3 of the focus range F3-F5, which is one of the five focus ranges (F1-F5) and includes the distance L1-L5 of the identification code 4.

[0032] 5 is an example of a distance map in which two focus ranges (F1, F2) are set according to the distance L1-L5 of the identification code 4. The focus drive position of the imaging unit 11 is determined based on the focus range in the distance map and the distance of the identification code 4.

[0033] In FIG. 5, the identification code 4 can be detected by setting the focus drive position of the imaging unit 11 to focus positions D1 and D2 in focus ranges F1 and F2 that include the distances L1-L5.

[0034] <Detection of identification code> The identification code detection device 10 determines the focus drive position of the imaging unit 11 according to the focus range in the generated distance map, and detects the code information of the identification code 4 using the image information of the identification code 4 acquired at the determined focus drive position.

[0035] In Figure 4, the distance L3 of the identification code 4 is included in F3, the distance L5 of the identification code 4 is included in F4, and the distances L1, L2, and L4 of the identification code 4 are included in F5. Therefore, by adjusting the focus drive position of the imaging unit 11 to D1, D2, and D3, the identification code 4 located at the distance L1-L5 can be detected.

[0036] Here, the focusing range F5 includes the distances L1, L2, and L4 of the identification code 4, so by adjusting the focus drive position of the imaging unit 11 to F5, the three identification codes 4 can be detected.

[0037] In Figure 5, distances L3 and L5 of identification code 4 are included in F1, and distances L1, L2, and L4 of identification code 4 are included in F2, so by adjusting the focus drive position of the imaging unit 11 to D1 and D2, it is possible to detect identification code 4 located at distance L1-L5.

[0038] Here, the focusing range F1 includes the distances L3 and L5 of the identification code 4, and the focusing range F2 includes the distances L1, L2, and L4 of the identification code 4, so five identification codes 4 can be detected with fewer focus drive positions compared to the distance map in Figure 4.

[0039] In this way, by determining the focus drive position of the imaging unit 11 according to the focus range in the distance map created according to the distance between the imaging unit 11 and the identification code 4, it is possible to obtain images of multiple identification codes 4 in focus within one focus range, making it possible to detect code information of multiple identification codes 4 at positions with different distances with fewer focus drive operations without performing focus drive operations for each individual identification code 4.

[0040] <Operation flow of the identification code detection device> The operation of the identification code detection method executed in the identification code detection device 10 will be described with reference to Fig. 6. Fig. 6 shows an example of the operation flow of the identification code detection method according to the embodiment of the present invention.

[0041] Each step of the identification code detection method is performed in an identification code detection device 10 that includes an imaging unit 11 that acquires image information including an image of the identification code, a distance measurement unit 13 that measures the distance from the imaging unit to the area of ​​the identification code in the image information, a distance map generation unit 14 that uses the measurement results of the distance measurement unit to generate a distance map that shows the relationship between the subject distance and the focus range, and an identification code detection unit 15 that detects code information of the identification code using the image information acquired by the imaging unit 11 in accordance with the focus range in the distance map.

[0042] The imaging unit 11 of the identification code detection device 10 acquires image information including an image of the identification code (S1-1).

[0043] The distance measurement unit 13 of the identification code detection device 10 extracts an area of ​​the identification code from the image information containing a plurality of identification codes acquired by the imaging unit 11 (S1-2).

[0044] The distance measurement unit 13 of the identification code detection device 10 uses the distance sensor unit 12 to measure the distance from the imaging unit 11 to each of the extracted areas of the identification code (S1-3).

[0045] The distance map generating unit 14 of the identification code detection device 10 uses the measurement results of the distance measuring unit 13 to generate a distance map that indicates the relationship between the subject distance and the focus range (S1-4).

[0046] The identification code detection unit 15 of the identification code detection device 10 determines the focus drive position based on the distance between the focus range of the distance map and the area of ​​the identification code (S1-5).

[0047] The imaging unit 11 of the identification code detection device 10 acquires image information including the identification code in the focus range that includes the distance of the area of ​​the identification code according to the determined focus drive position (S1-6).

[0048] The identification code detection unit 15 of the identification code detection device 10 detects the code information of the identification code using the image information acquired by the imaging unit 11 in accordance with the focus range in the distance map (S1-7).

[0049] The focus driving and the detection of the identification code information are repeated until the identification code is detected at all the determined focus driving positions (S1-8).

[0050] In this embodiment, when detecting code information of multiple identification codes 4 assigned to luggage 2 placed at positions with different distances, the imaging unit 11 acquires image information (first image information) containing the multiple identification codes 4, extracts the identification codes 4, measures the distance between the extracted identification codes and the imaging unit 11, generates a distance map showing the relationship between the subject distance and the focus range using the measured distance, determines the focus drive position of the imaging unit 11 according to the focus range in the generated distance map, and detects the code information of the identification codes 4 using the image information (second image information) of the identification codes 4 acquired at the determined focus drive position.

[0051] According to this embodiment, by determining the focus drive position of the imaging unit 11 according to the focus range in a distance map created according to the distance between the imaging unit 11 and the identification code 4, it is possible to obtain images of multiple identification codes in focus within one focus range, and therefore it is possible to detect code information of multiple identification codes 4 at positions with different distances with fewer focus drive operations, without performing focus drive operations for each individual identification code.

[0052] According to this embodiment, it is possible to provide an identification code detection device that can accurately detect code information of a plurality of identification codes using a simple method. [Explanation of symbols]

[0053] 1...Identification code detection system, 2...Luggage, 3...Pallet, 4...Identification code, 10...Identification code detection device, 11...Imaging unit, 12...Distance sensor unit, 13...Distance measurement unit, 14...Distance map generation unit, 15...Identification code detection unit, 16...Memory unit, 17...Input unit, 18...Display unit, 19...Wireless unit, 20...Identification code management server.

Claims

1. an imaging unit that acquires image information including an image of the identification code; a distance measurement unit that extracts areas of the identification codes from first image information acquired by the imaging unit, the area including a plurality of identification codes, and measures a distance from the imaging unit to each of the extracted areas of the identification codes; a distance map generation unit that generates a distance map indicating the relationship between the subject distance and the focusing range using the measurement result of the distance measurement unit; an identification code detection unit that detects code information of the identification code using second image information acquired by the imaging unit in accordance with the focus range in the distance map; Equipped with The imaging unit acquiring the second image information including at least one of the identification codes in the focus range that includes the distance between the focus range and the identification code area, according to a focus drive position determined based on the distance between the focus range and the identification code area; The identification code detection unit Detecting code information of the identification code in the second image information Identification code detection device.

2. The distance map generation unit generating the distance map in which the focus ranges are set so that at least one of the focus ranges includes the distances of the regions of the plurality of identification codes; The imaging unit The second image information including the plurality of identification codes is acquired within the focusing range set in the distance map.

2. The identification code detection device according to claim 1.

3. an identification code detection method executed in an identification code detection device including an imaging unit that acquires image information including an image of an identification code; a distance measurement unit that measures the distance from the imaging unit to an area of ​​the identification code in the image information; a distance map generation unit that generates a distance map indicating the relationship between subject distance and focusing range using a measurement result of the distance measurement unit; and an identification code detection unit that detects code information of the identification code using the image information acquired by the imaging unit in accordance with the focusing range in the distance map, acquiring, by the imaging unit, first image information including an image of the identification code; a step in which the distance measurement unit extracts areas of the identification codes from first image information including a plurality of identification codes acquired by the imaging unit, and measures a distance from the imaging unit to each of the extracted areas of the identification codes; a step in which the distance map generation unit generates a distance map indicating a relationship between an object distance and a focus range using the measurement result of the distance measurement unit; the identification code detection unit detects code information of the identification code using second image information acquired by the imaging unit in accordance with the focusing range in the distance map; and The imaging unit acquiring the second image information including at least one of the identification codes in the focus range that includes the distance between the focus range and the identification code area, according to a focus drive position determined based on the distance between the focus range and the identification code area; The identification code detection unit Detecting code information of the identification code in the second image information Identification code detection method.

4. The distance map generation unit generating the distance map in which the focus ranges are set so that at least one of the focus ranges includes the distances of the regions of the plurality of identification codes; The imaging unit The second image information including the plurality of identification codes is acquired within the focusing range set in the distance map.

4. The method for detecting an identification code according to claim 3.

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