Identification code detection device and identification code detection method

Abstract

To provide an identification code detection device which can accurately detect code information on a plurality of identification codes.SOLUTION: An identification code detection device 10 according to the present invention includes: an image-capturing unit 11 which acquires a captured image 2 including images of identification codes 3; a distance measurement unit 14 which measures distances to the identification codes 3; and an identification code detection unit 15 which extracts information on a frequency band including frequency components of the images of the identification codes 3 from the captured image 2 to thereby detect code information on the identification codes 3 while changing the frequency band according to the distances between the identification codes 3 and the image-capturing unit 11.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 luggage. [Background technology]

[0002] As a technology for managing luggage in a warehouse, a method for managing the presence or absence of luggage in the warehouse and the location of the luggage by reading an identification code attached to the luggage is being implemented. For example, Patent Document 1 proposes a system that uses a scanner to read an identification mark for identifying a product to be managed and an identification mark for identifying the location where the product is placed, compares the read actual number data of the product with product data stored in a database, and rewrites the product inventory record in the database. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-101424 A Summary of the Invention [Problem to be solved by the invention]

[0004] The system of Patent Document 1 uses a scanner to individually read multiple identification marks for identifying products to be managed, but recently, technology has been put to practical use that simultaneously reads multiple identification codes using a high-resolution camera mounted on a mobile terminal such as a smartphone. Information on multiple identification codes can be extracted by extracting information on the frequency components of the identification codes from an image captured by the camera of the mobile terminal, but since the frequency components of the identification codes vary depending on the distance between the mobile terminal and the identification code and the size of the identification code, the identification code may not be detected accurately depending on the distance between the mobile terminal and the identification code.

[0005] The present invention has been made to solve such problems, and has an object to provide an identification code detection device that can accurately detect the code information of multiple identification codes even when the distance between the mobile terminal and the identification codes varies. [Means for solving the problem]

[0006] In order to solve the problems described above, the identification code detection device of the present invention comprises an imaging unit that acquires a captured image including an image of an identification code, a distance measurement unit that measures the distance between the identification code, and an identification code detection unit that detects code information of the identification code by extracting information of a frequency band including the frequency components of the image of the identification code from the captured image, and the identification code detection unit is configured to change the frequency band depending on the distance between the identification code.

[0007] The identification code detection unit may be configured to select the frequency band corresponding to the distance from the identification code, based on a predetermined correspondence relationship between the distance from the identification code and the frequency band.

[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 in an identification code detection device including an imaging unit, a distance measurement unit, and an identification code detection unit, the method comprising the steps of: a step of the imaging unit acquiring a captured image including an image of an identification code; a step of the distance measurement unit measuring a distance between the identification code; a step of detecting code information of the identification code by extracting information of a frequency band including a frequency component of an image of the identification code from the photographed image by the identification code detection unit; having The identification code detection unit changes the frequency band depending on the distance to the identification code.

[0009] The identification code detection unit may select the frequency band corresponding to the distance from the identification code based on a predetermined correspondence relationship between the distance from the identification code and the frequency band. Effect 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 even when the distance between the mobile terminal and the identification codes varies. [Brief description 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. [Diagram 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. [Diagram 3] FIG. 3 is a diagram for explaining a frequency table according to the embodiment of the present invention. [Figure 4] FIG. 4 is a diagram for explaining an operation of detecting an identification code according to the embodiment of the present invention. [Diagram 5] FIG. 5 shows an example of an operational flow of the identification code detection method according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[0013] <Baggage management system configuration> 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 a photographed image 2 including an identification code 3 and detects the identification code 3 using the acquired photographed image 2, and an identification code management server 20 that manages information on the identification code detected by the identification code detection device 10.

[0014] Since the identification code 3 has a specific frequency component, it is possible to extract information on a plurality of identification codes by extracting information on the frequency component of the identification code 3 from a captured image containing the identification code 3. Here, since the frequency component of the identification code 3 varies depending on the distance between the identification code detection device 10 and the identification code 3 and the size of the identification code 3, the identification code 3 may not be detected accurately depending on the distance between the identification code detection device 10 and the identification code 3.

[0015] In this embodiment, when extracting the frequency components of the identification code 3 from the captured image 2 including the identification code 3, the frequency band used to extract the frequency components of the identification code 3 is changed depending on the distance from the identification code 3. The value of the frequency components of the identification code 3 varies depending on the distance between the identification code detection device 10 and the identification code 3, but by changing the frequency band used to extract the frequency components of the identification code 3 depending on the distance between the identification code detection device 10 and the identification code 3, the accuracy of extraction of the frequency components of the identification code 3 can be improved.

[0016] <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.

[0017] The identification code detection device 10 comprises an imaging unit 11 for acquiring a captured image including an identification code 3, a distance sensor unit 12 for measuring the distance from the identification code 3, a central processing unit 13 that measures the distance from the identification code 3 using the distance sensor unit 12 and detects code information of the identification code 3 by extracting the frequency components of the image of the identification code 3 from the captured image 2, 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, and a wireless unit 19 for transmitting and receiving information to and from an identification code management server 20.

[0018] The central processing unit 13 functions as a distance measurement unit 14 that measures the distance to the identification code 3 using the distance sensor unit 12, and an identification code detection unit 15 that detects code information of the identification code 3 by extracting information of a frequency band that includes the frequency components of the image of the identification code 3 from the captured image 2 of the imaging unit 11.

[0019] The identification code detection unit 15 is configured to change the frequency band including the frequency components of the image of the identification code 3, using the measurement result of the distance to the identification code 3 measured by the distance measurement unit 14. This makes it possible to reliably extract the frequency components of the image of the identification code 3 even if the distance to the identification code 3 varies.

[0020] The storage unit 16 stores a frequency table indicating the correspondence relationship between the distance from the identification code 3 and the frequency band including the frequency components of the image of the identification code 3. The identification code detection unit 15 can select a frequency band including the frequency components of the image of the identification code 3 according to the distance from the identification code 3, based on the correspondence relationship between the distance from the identification code 3 and the frequency band stored in the storage unit 16.

[0021] 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. For the distance sensor unit 12, a general-purpose distance measurement sensor such as a TOF (Time of Flight) sensor or a LiDAR sensor can be used.

[0022] The identification code detection device 10 can be configured by a computer equipped with a CPU, a memory, and an interface for connecting to an external device.

[0023] <Frequency table configuration> 3 is a diagram for explaining a frequency table according to an embodiment of the present invention. The frequency table is a table in which the correspondence between the distance to the identification code 3 and the frequency band including the frequency component of the image of the identification code 3 is registered.

[0024] 3, frequency bands of the identification code 3 corresponding to three shooting distances #1-#3 (close to long) are registered. The frequency band including the frequency components of the image of the identification code 3 can be obtained by Fourier transforming the image of the identification code 3 obtained at each shooting distance.

[0025] In the configuration example of FIG. 3, frequency bands of identification codes corresponding to three shooting distances #1-#3 (close to long distances) are registered, but this is not limited thereto, and frequency bands corresponding to more shooting distances may be registered.

[0026] Since the frequency components of the image of the identification code 3 differ depending on the size of the identification code 3, it is possible to register in advance the frequency bands of the identification code 3 corresponding to the shooting distance for each size of the identification code 3, as shown in FIG. 3, in case of detecting identification codes 3 of multiple sizes.

[0027] <Detection of identification code area> The operation of detecting the identification code 3 executed in the identification code detection device 10 will be described with reference to Fig. 4. Fig. 4 is a diagram for explaining the operation of detecting the identification code according to the embodiment of the present invention.

[0028] The identification code detection device 10 acquires a captured image 2 including an image of an identification code 3, and uses the measurement result of the distance measurement unit 14 to select a frequency band in the frequency table.

[0029] The identification code detection device 10 extracts the identification code area in the captured image 2 by extracting information on the frequency components of the image of the identification code 3 from the captured image 2 using a bandpass filter whose passband is the selected frequency band.

[0030] The identification code detection device 10 uses the image in the extracted identification code area to detect the code information of the identification code 3. The code information of the identification code 3 can be detected by A / D converting the image of the identification code in the identification code area.

[0031] <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. 5. Fig. 5 shows an example of an operation flow of the identification code detection method according to the embodiment of the present invention.

[0032] The imaging unit 11 of the identification code detection device 10 acquires a captured image 2 including an identification code 3 to be detected (S1-1). If the captured image 2 includes multiple identification codes 3, images of the multiple identification codes 3 may be acquired all at once, or the captured image 2 may be acquired by selecting the identification code 3 to be detected from the multiple identification codes 3.

[0033] The distance measurement unit 14 of the identification code detection device 10 measures the distance to the identification code 3 (S1-2). When the captured image 2 includes multiple identification codes 3, a representative identification code 3 may be selected from the identification codes 3, and the distance to the representative identification code 3 may be determined as the distance to the identification code 3, or the average value of the measured distances for the multiple identification codes 3 may be determined as the distance to the identification code 3.

[0034] The identification code detection unit 15 of the identification code detection device 10 selects a frequency band in the frequency table according to the distance to the identification code 3 measured by the distance measurement unit 14 (S1-3).

[0035] The identification code detection unit 15 of the identification code detection device 10 uses the selected frequency band to extract an identification code region containing frequency components of the image of the identification code 3 from the captured image containing the image of the identification code 3 (S1-4).

[0036] The identification code detection unit 15 of the identification code detection device 10 detects the code information of the identification code 3 using the image in the extracted identification code region (S1-5).

[0037] In this embodiment, when extracting the frequency components of the identification code 3 from a captured image 2 containing the identification code 3, the frequency band used to extract the frequency components of the identification code 3 is changed depending on the distance between the identification code detection device 10 and the identification code 3.

[0038] According to this embodiment, even if the distance between the identification code detection device 10 and the identification code varies, the accuracy of extracting the area of ​​the identification code 3 can be improved, making it possible to accurately detect the code information of multiple identification codes. [Explanation of symbols]

[0039] 1...identification code detection system, 2...captured image, 3...identification code, 10...identification code detection device, 11...imaging unit, 12...distance sensor unit, 13...central processing unit, 14...distance measurement 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 for acquiring a captured image including an image of an identification code; a distance measurement unit for measuring a distance between the identification code; an identification code detection unit that detects code information of the identification code by extracting information of a frequency band including a frequency component of an image of the identification code from the captured image; Equipped with The identification code detection unit is configured to change the frequency band depending on the distance to the identification code. Identification code detection device.

2. The identification code detection unit is configured to select the frequency band corresponding to the distance from the identification code based on a predetermined correspondence relationship between the distance from the identification code and the frequency band.

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, a distance measurement unit, and an identification code detection unit, comprising: a step of the imaging unit acquiring a captured image including an image of an identification code; a step of the distance measurement unit measuring a distance between the identification code; a step of detecting code information of the identification code by extracting information of a frequency band including a frequency component of an image of the identification code from the photographed image by the identification code detection unit; having The identification code detection unit changes the frequency band in accordance with a distance between the identification code and the Identification code detection method.

4. The identification code detection unit selects the frequency band corresponding to the distance from the identification code based on a predetermined correspondence relationship between the distance from the identification code and the frequency band.

4. The method of claim 3.

Images